#66: Winemaker Tools for Coffee Producers: Sugar & Acid Additions, Co-Fermentation w/ Fruit

I was going to create a new episode about Infused vs Inoculated Coffees, but much of what we established back in Episode #39 is still relevant. So I am pulling a Taylor Swift and going to re-release a new version of episode 39, keeping what still works and adding some new perspectives from the last 3 years.

In this episode I talk about:

• The sugar and acid additions that French and California winemakers use
• How adding mango to a fermentation tank is completely different from adding passion fruit or citrus
• How to tell when a coffee is infused with a flavor
• Cinnamon flavor in a coffee
• Inoculation vs Infusion vs Co-Fermentation
• The role of enzymes in removing mucilage
• Gravity!

Inquiries about coffee samples or future Fermentation Training Camps: info.luxiacoffee@gmail.com

Support the show on Patreon  to join our live Discord hangouts, and get access to research papers, transcripts and videos.

And if you don't want to commit, show your support here with a one time contribution: PayPal

Sign up for the newsletter for behind the scenes pictures.

Cover Art by: Nick Hafner
Into song: Elijah Bisbee

Transcript

lucia: 0:20

Hello, and welcome to episode 66. Happy August, everybody. Last week as I'm recording this on August 8th and ninth, I attended the Annika fake. in Guatemala city. And they gave a talk about the role of microbiology and coffee processing. And a big focus of the talk was disambiguating infused adulterated and fermented coffees. I also recently did a Hoka. Cafe, which is my other Spanish language podcast for producers. Uh, exploring these themes and explaining them in a lot more detail. And after we kind of did both of those things need to ask me why we didn't have I'm making coffee episode about the same topic. And I didn't think about it because I was sure I had already covered it. in my head. It was recently, but I have been getting more questions lately about the topic and I'm seeing more criticism and confusion about what qualifies as an infused coffee. So I considered bringing up the theme again, but because I was pretty sure I had already covered it. I went back into the archives and it turns out that I had already covered it, but it was three years ago. It was back in September, 2021. When we first had this conversation. And that got me thinking too. The different ways that, you know, there's a disconnect between how I have been approaching the podcast to how most people enjoy podcasts. And due to their episodic nature. I think there's a bias for recent episodes and recent information. Most people when they start a new podcast or they hear about a new podcast, new to them, they start listening when they become aware of the podcast and become regular listeners from that point forward. I think there are very few souls who go back all the way to the beginning and start there. But I know there are those of you and I'm, I tend to be one of those people as well. And I like to have the whole kind of I'm a completist. So I know that when you guys go back to the beginning of the podcast, you try to reach out and you tell me about it. So I know that there are some special unicorns that do that. Listen to podcast in this way. Well, the reason I started a podcast in the first place was to have an audio library so that the knowledge would be accessible and would just kind of exist. Somewhere outside of my brain at any moment. And since we talk about scientific principles, the information doesn't really go stale because there are no trends to keep up with. Actually, I will also share with you attention. I've been feeling about how to bring the podcast to a close. Since my original goal was to have an audio library. The more new episodes that get piled on top, the less relevant the earlier episodes are. And I believe that the earlier ones are some of my best and my favorite. So when a podcast has 300 episodes, few people go back and listen to episode number 15, they want to hear episode 300 and 301. So I've been feeling like the more new episodes I have. It has this unfortunate effect of burying the ones that already exist. When I dreamed up the idea of making coffee, I thought of it more like an audio book, a discreet container of information, not an ongoing rolling perpetual machine. So I'm not ending the podcast today, but I definitely think about how I can avoid falling into that trap of so many of my favorite TV shows. Who don't know when to end. The storyline ended, but the show was so popular that they pump out another season and another, and ultimately end up diluting the memory of the whole thing. So this brings me back to the idea of what to do with old information on the timeline. But. That doesn't really make sense because it's not old information, the information itself, especially when we're talking about scientific principles. Is evergreen, but maybe episode was again three, four years ago. The episodes I've done about how microbes great flavor are still accurate today. But again, it's from four years ago. And I didn't want to bore you, our listeners with the same topics over and over again. But I think that some things bear revisiting. So I was going to create a new episode about infused coffee, but so much of what we established back in episode 39 is still relevant. So kind of being inspired by Taylor swift in the sense, and I'm going to rerelease a new version of episode 39. This is a rerecording I'm keeping what still works. adding some new perspective from the last three years and cutting some of the stuff that potentially was specific to that time several years ago. I started the episode in September 21. By telling you about our discord office hours. These are informal virtual Hangouts that I have monthly, where we chat about whatever is on our minds. Despite the casual nature of the live Hangouts, as you'll see in this. Coming up is owed. We can still get pretty complex pretty quickly. And episode 39 was inspired by what happened during one of our sessions. One of our podcasts after the podcast. Because in episode 38, I had interviewed Phillipa to heal from Ventura coffee in Antioquia Colombia. And Lucas Quadros from unblended coffee. After the episode, I invited them to our discord hangout. So listeners to the podcast could ask them questions directly and we could just kind of keep chatting casually about some of the topics that came up during the official podcast. And a few things that stick out to me from that conversation. I wanted to share here and a new episode, because what started as a fun hangout, turned out to provide key insights for coffee producers. If you listen to episode 38. You'll know that Philippe is a curious guy and truly enjoys experimenting with his coffee. He has a certain kind of producer and definitely not the norm and definitely not the model of most coffee producers in the world. And episode 38, we talked about Philippe's kombucha processed coffee, a nontraditional way to process coffee, especially in Latin America. And then later he started the discord session by telling us he did a fermentation adding right mango fruit to his coffee. He was the first to say that adding mango to a coffee fermentation tank doesn't result in the coffee, having a mango flavor. So I'm going to say this again, right? Repeat it for the folks in the back. Adding whole fruit to a coffee tank. Usually doesn't transfer the flavor of that fruit into the coffee. So while we were having this discussion, another patron on the live call asked him, okay. But if adding mango, does it make it taste like mango? Why do it? What does it taste like? And it was hard for Philippe to point out a singular attribute, but he said it made the coffee really complex that it had a positive result. He liked it. His client liked it and it worked for him. So it was something that he was no. Now in his toolbox. But let's back up for a moment. You've probably tasted mango notes in your coffee before. And if you haven't trust me, it really can happen. Sometimes a cup of coffee can taste like one of those fruit cups snacks you'd get in your lunch box as a kid. The kind with the cubed peaches and maraschino cherries just wrapped in syrup. Many flavor descriptors that sound like they are made up by coffee stops or marketing can actually be measured by scientists. If you taste mango flavor in your coffee, science can back you up. Yes, it's possible. And we can measure it. Coffee can taste like someone squeezed mango juice into your cup. If you're a new listener to the podcast and this interests you, I recommend you go back to episode 15, where we deeply talk about how this happens. And that episode, I talk about important research where scientists have identified the chemical components of Jasmine and peaches and pineapple and banana, and can trace them back to the microbes that produce them. And as part of your Patrion membership, you can download the original research papers to see the full table with like a hundred different descriptors and their chemical precursors. But because not everyone has a patience to read scientific papers. I will tell you that mango flavor is attributed to beta myrcene and beta myrcene is an abundant monitoring. This compound has been identified in the coffee fermentation and also in roasted coffee. This means that scientists know that the compound was made in the fermentation stage and that it survives the intense heat of roasting. If it only showed up in the roasted coffee and not in the green fermented coffee. Then we could assume that it is synthesized during roasting and from other precursors. But that's not the case with many of these fruity descriptors, they are found in the fermented green coffee and they can also be found in the roasted coffee. In addition to that scientists have also connected east like Saccharomyces service EA and Pichia as microbes that produce turpines. So mango flavor, coffee doesn't happen from putting mangoes in a coffee tank. It comes from having yeast like Saccharomyces and pickier breaking down glucose to produce monoterpenes that tastes like mango. These are basically yeast, farts. Delicious, delicious. E-sports. The other part that I find interesting is that this is not necessarily cutting edge coffee science. We've known this for a long time. Research by Hernandez, Espinosa, Fernandez, Gonzalez, and Brian's dates back to 2003, which was 21 years ago. I'm quoting their paper right now to share what they found. They say. The turpines formed during the coffee mucilage removal process, beta Citra, novel linalool, geranium, and alpha terpene Yael. All originate through yeast, beta glycosade days. Enzymes. In addition, some yeast species found in coffee fermentation, for example, Saccharomyces cerevisiae to realist Bora Del brekkie. And hence any S Bora. Vara can produce terpene derivatives through the mevalonate asset pathway. That citation is from 2005. So perhaps it took a few more years to identify the mechanism of how this happens from 2003 to 2005. even as scientists already knew that it did happen, it just took that extra step to be able to figure out exactly the pathway of how these flavors are produced by these microbes. And then a few years later in 2013 Silva at L showed that linalool produced by coffee associated Saccharomyces cerevisiae and picky at Guillermo. can be detected in beans after the roasting process. The bottom line is this various studies have shown that microbial derived metabolites can diffuse into seeds and remain after the roasting process. Including esters, higher alcohols aldehydes ketones. And terpenoids. But maybe there are some flavors that you think only come from roasting, for example, butterscotch. I have often had coffees that tastes like where there's butterscotch candies. And I thought that was a purely roast related flavor. But butterscotch flavor has been detected in the fermentation. The chemical that tastes and smells like butterscotch is one hydroxy, two Buda note. It's a ketone. Scientists have also identified a yeast with the romantic name of yarrow yet. At lipo Lyrica, N C Y C 2 9 0 4. That synthesizes Buda known. This challenge is the traditional conventional thinking that all of the flavor came from roasting. Even perhaps some roasted flavors. This is important because we used to use a logic that if you drink green beans, well, you know, they taste like pretty much nothing. But if you roast them and drink them, then it's delicious. So the thinking the very simplistic thinking was it must be the roasting and maybe only the roasting that makes them taste good. And this reasoning is behind the business of buying commodity green coffee. Green coffee seeds were seen as kind of a nerd. You just buy them from wherever they were cheapest. For example, say you normally buy Guatemalan coffee for$2 a pound, but then Guatemala has a terrible harvest season due to climate change. And farmers lose 30% of their yield. So the supply is reduced and the price goes up. Suddenly the price is raised to two 50. Which maybe 50 cents doesn't seem like a lot, but suddenly your cost as a buyer have gone up 25%, which is significant increase. The green coffee is just a raw material. So you exchange it for a cheaper option. You see that you can get green coffee for$2 a pound from Honduras or Vietnam. So then you buy that. You have the luxury of buying only on price because you believe the quality comes from the roasting step. And honestly, the previous example is actually very unrealistic. because what's more likely to happen is that if Guatemala has a bad crop year and producers have a 30% less yield and the supply is significantly less. the farmers, usually aren't the ones who are setting the price. So it's not likely that they, they themselves can raise their prices. It will probably still keep getting paid the same price despite the changing conditions. but producing less coffee. So then therefore going into a spiral of debt, where the more coffee that they produce, the more debt they are in because their cost of production increases, but they are getting paid below that cost of production to produce that coffee. And the answer that we have to most producers who aren't getting paid enough as well, just make more coffee, so you have more coffee to sell. So it's a very circular kind of downward spiral system. And I didn't mean to get lost on that tangent, because this is not an episode about coffee economics. So we're going to put that aside for a moment and go back to talking about the interchangeability of commodity coffee about this. Question about flavor. The example I came up for, this is, let's say you're a carpenter and someone ordered a table from you. And you like to work with Redwood. So you make a table from that and you sell it at a price that you feel comfortable with. But now you get a new order for 40 tables, let's say for a restaurant and that person wants a volume discount. They are buying more. So they want to pay less per table. Suddenly you realize it's too expensive to use Redwood for all those tables. So maybe you look into buying something like a pine. The most important concern for the restaurant is to have 40 tables. So if you switch out Cedar for pine it's okay. Because at the end you will still have a table. And most of the value there, the exchange is in the craft, not in the wood that you use, not in the raw material. It's the craftsmanship. The value is, and the person who turns the wood into a table. I think this is how many first and second wave roasters thought of green coffee as the owner raw material of the craftsmen. And the roaster was the one who turned it into the final product. So that's where a lot of the value add came from. So you could switch out origins and buy whatever happens to be cheaper because you didn't really feel like it affected the final product because you are the artist, not the raw material. Right? The green coffee was just the paint that you use to create, to paint your masterpiece. I knew what specialty this paradigm is absolutely changing. We now know that different origins have different flavors. when we talk about specialty coffee, we talk about appreciating the origin and what makes these coffees different. And it's all about where the coffee came from, how it was grown. Was it organic? we've even taken the step to care about varieties. We all have people that are much more aware of. Are they drinking a bourbon or a buck, a Mata, or I've got. Or a geisha. And all this as well and good. But while I believe we are headed in a better direction, I still feel like many miss an important opportunity in this paradigm shift. I still think many, even in specialty failed to see the producer as an artist as well. We value nature and climate and origin, and we value the roasting transformation in brewing. And too frequently, the producer is left out of the equation or perhaps just overlooked. In fact many in specialty believe it's the producer's job to get out of the way to show the transparency of what nature intended for the coffee. This sounds romantic, but what it implies is that we believe consciously or unconsciously. The coffee producers should be seen and not heard. For many in specialty, we believe a producer has done a good job. When they have not left a mark on their coffee. They're successful only when the coffee is a transparent expression of the land. For many in specialty, a coffee producer is successful when they quietly fade into the background. And what kind of bullshit empowerment is that? I think that's the message. Many coffee producers wrestle with. We tell them that specialty coffee is different from commodity because now they have a role. Now we care about how the coffee was produced, but their role is largely to not steal the show from the variety and the climate. It's like we're letting them into the meeting, but telling them to stand quietly in the corner and not say anything. And then we congratulate ourselves on being progressive and inclusive. This is why I made the terroir series, not to say that I don't believe in terroir as a concept, which is surprising how many people think that that's the takeaway. but I made it to show that the concept of terroir simultaneously makes us feel we value coffee more. While relegating coffee, producers to silent partners. And maybe you think I'm being dramatic. Maybe these episodes are prone to drama. But before you dismiss these ramblings, I want to talk about a term I've been hearing that I really disagree with. Adulterated coffee. There's a part of the industry. A small, but very vocal part who would like coffees labeled as doctored or infused if they have some non-coffee element as part of the processing. The reasoning behind this call for transparency from coffee. Producers is said to stem from keeping integrity in coffee competitions. There's that word again? Transparency. And this word I find difficult because it most often seems to be leveraged against coffee producers. The industry calls for transparency. So coffee producers don't hide what nature and climate provide the industry calls for transparency. So coffee producers, don't trick baristas into competing with so-called doctored coffees. Which. It gives me the image of, I think, you know, coffees are doping and getting an unfair advantage and that. They doping copies are undermining the true winners. But I don't think this is what's really happening. Again, I really don't like to comment on anything related to coffee competitions, because I'm pretty ignorant on that matter. This is not an episode about economics or coffee, competitions or baristas. It's an episode about science and history. So I will try to stay focused. My impression from being in his copy space. Is that almost everyone else in the coffee value chain stands to gain from transparency. But coffee producers, they're not seeing the same type of benefits. I think that consumers gain by feeling good about the coffee purchases they're making. Marketers gained by being able to position the coffee in a different market. But what are farmers and producers gaining from transparency? If you're a producer and you feel like you've gained something, please let me know. I would love to be wrong about this. I would be happy if this wasn't the case. I just don't have any evidence of it. I haven't seen it myself. Like I said, I don't feel qualified to talk about coffee competitions or their impact on the coffee industry. But I am here to support coffee producers. And I think with all the talk of transparency, not only are we not including them enough, but we are also forgetting a fundamental truth of coffee. But before we get to that fundamental truth. Let's review some science. Like I said earlier, putting a fruit in a coffee tank is not enough to make it taste like that fruit. During the fermentation, they microbes need to synthesize the flavor compounds and make them small enough to get into the green coffee seed. To fennel, ethyl alcohol, which is the rose compound is a higher alcohol. Researchers have founded in the seeds of cherries and also instrumented copy. This means that this floral, this rose component could be attributed either to the varietal or to the coffee fermentation. Or perhaps the coffee fermentation could be boosting some of the compounds that are already found in that parietal. So yeast, commonly synthesizes, a great variety of higher alcohols during coffee fermentation. Saccharomyces pick yet candida and the bacteria lactobacillus plantarum all produce higher alcohols. Rose Jasmine balsamic butterscotch, and a thousand other volatiles have been identified by researchers as able to come from a copy fermentation. But you know what they haven't found yet. Cinnamon. Researchers do not have the link between cinnamon and microbial activity. It's possible that there is a micro out there that produces a flavor cinnamon as a metabolite. But as of today, it has not been found. So, if you're curious about infused coffee, cinnamon is a good clue. But almost everything else, almost all of these other seemingly esoteric flavor compounds. It's very likely have a biological basis, a fermentation basis. And I'm not saying it's not possible to add essential oils or to otherwise perfume coffee. Of course it is. But just because I, coffee has a certain flavor, you can't assume that it was doctored because there could be a biological explanation. Maybe other thing I want to add about this point is that having a certain flavor profile in a coffee, doesn't necessarily immediately signal this coffee is infused, but I do think that we have very strong clues in terms of intensity. We can. We do have these baselines of, if you do have rose or strawberry or mango flavor in a coffee. If you can find that. There is a baseline of what is found in nature. And then when we test these coffees, we can say, oh, well, in this coffee, it happens to be 10 times anything that's ever been found in nature. Therefore, we can clearly deduce that this copy has been infused with a certain flavor. So I think that when we are going to try these copies or potentially judged them, and maybe it's not being disclosed, whether or not they were infused. Not to look at just the flavor profile, but to look at the flavor profile, plus the intensity of that flavor. And the other point of talking about this is when does a term infused apply? And I think that, you know, if cinnamon is added to a tank, even if it's during fermentation or at any point in the coffee making process, I think that the term infused could be applied should be applied because the point of adding cinnamon. To coffee. Is to get cinnamon flavor out. It's like, you know, one in one out, one cinnamon in one cinnamon out, and there is not a strong case for a microbial basis for this process. But I know that there are a lot of people who would like to use the term infused. For any fermentation that has fruit. Involved when there's any. Kind of addition to the tank. And I don't think that should apply, especially in the case of added fruits in a coffee tank. Because the direct flavor of the fruit is not being incorporated into the coffee. The fruit in the case of mangoes serves as a fuel source for the microbes, you are not infusing mango flavor by adding whole fresh fruit mangoes. What you're doing is that you're feeding the microbes that can transform. Those metabolites into precursors that become the flavor. It's a very indirect transformation of flavor. And I think that's the big key that I want you to keep in mind is. When it's microbes, it's a transformation of one thing to another. And when it's an infusion is a direct preservation, it's a one-to-one we put in cinnamon. We want to get cinnamon out. We put in. Uh, orange essential oil. We want to get out an orange flavor in our coffee. When we're adding yeast, we don't want the coffee to taste like yeast. You're not adding yeast to get a yeast flavor. You're adding yeast to that. The yeast can transform the precursors and make something else. So I think that's, you know, two big categories and too often, I see these two things just jammed into one category. And there are definitely very different mechanisms. With very different aims. And to give you an example of feeding the microbes of how we get this transformation. I want to give you a wine example. The process of adding sugar in wine is called chapterization because in France, the growing season can be really difficult, not warm enough. And some years there is not enough sun and the grapes do not ripe it enough so that you don't get enough sugar accumulated in the grapes to then turn those grapes into a wine. And this is a problem. This is a hazard because if you don't have enough, Initial sugar to convert into alcohol and you get really low alcohol. levels. The alcohol is a tool to preserve the wine longterm. So if you don't get high enough alcohol levels. The wine is. Less stable. So in France, you are allowed to chapterize the wine, meaning you can add sugar or you can add a sweet concentrate to the fermentation to make up for not having enough sunshine in a given year. And this is not a practice that is disclosed on bottles. This is not something that anybody says as an added ingredient at any point in their wine making process. This is just a common practice that winemakers. Sometimes need to resort to, to combat difficult years. In fact in the champagne region of France chapterization is an essential part of making the base wines for champagne. And in that industry, we do not think of these wines as infused or doctored or adulterated. We just think of them as champagne, like. That is just part of the process of sometimes nature doesn't provide. And of sunshine. We, the winemakers make a decision about that. And I think this is essentially what coffee producers are doing when they're adding fruit to coffee, fermentation tanks. Just like the great winemakers or France, they are chapter realizing their fermentation. But in contrast, no one in France is getting mad at the winemakers. They are just grateful to have delicious champagne. So, if you don't understand how microbes make metabolites, I understand how you could be confused and think that copies with fruit should be called adulterated or infused. But once you have more information, I hope many of you who previously thought it was a reasonable ask now, understand that it's quite silly to want coffee, to be labeled this way. In fact, there are some extreme opinions who think that if anything is added, it shouldn't be allowed to be called coffee. But perhaps a coffee based beverage. I think this is nonsense and shows an ignorance of science. But there's something that concerns me more than people who ignore science. I'm concerned about the people who do know how microbes make metabolites, who are informed on the science and who still believe that even adding a starter yeast or bacteria culture should be considered an adulteration. And an article by BMC magazine called why transparency must apply to infuse copies. I read something. I find very disturbing. The quote is. Additions during various stages of the value chain that are not naturally from the coffee itself, including adding microorganisms that are not part of the copy micro flora. Should be considered adulterated coffee and labeled accordingly. And quote. This totally floored me because we're not talking about adding essential oils or even tropical fruit. It's literally about microorganisms. And this was not sad by a consumer or a barista or roaster anybody on the consuming side. This was said by professor Dr. Johanne of the coffee, excellent center of the Zurich university of applied science. He and his colleagues are the ones doing the research to identify the volatile compounds that give coffee its flavor. He's an influential figure. And I'm disappointed to hear him take the stance. So publicly. I wholeheartedly disagree with the quote in reference to coffee. On the one hand, it's a reasonable point to want something labeled that is not original to the product, like adding corn or chicory to coffee. Or adding essential oils to get the coffee, to have the aroma of orange or Jasmine or whatever. So, yes. I believe some things should definitely be labeled. Some additives are unequivocally not original to coffee. But saying that if your producer who uses a starter culture of yeast or bacteria, That you as a producer should be required to label your coffee as adulterated. Is a bridge too far. And this is where we get back to the fundamental truth about coffee that we so often forget. As I covered in the terroir series about the podcast. Coffee is not original to where it grows. So I think it's hypocritical and arbitrary to say that we can import plants that are not native to where they are growing. But then turn around and say, you can only use native microbes to ferment them. You can take a plant from Ethiopia and grow it in California or Columbia or India. And that's okay. That's true. Coffee. But suddenly if you use yeast, that's not local to California or Columbia or India, you suddenly no longer have pure coffee and you must label it as adulterated. I mean, come on. If you're allowed to import the plant, why can't we also import the microbes that are needed, deferment that plant. As an industry, we can decide to make this arbitrary distinction. We can decree the coffee plant material must be imported, but fermentation microbes cannot. That's fine. We can decide that, but I hope that we have enough transparency to admit that it is a random, an arbitrary decision. I hope that we can have enough transparency about ourselves to say we decided this instead of hiding behind the label of natural or purity or true coffee and wanting to label things as unadulterated. Remember from the terroir episodes. When the coffee plants were taken from Ethiopia, they came naked. They didn't bring their original microbes with them. We are already fermenting with non-native micros. Coffee is already being asked to use foreign yeast and bacteria in every fermentation across the entire world. So when we changed the microbes by accident, by the colonial forces, looking to expand the coffee empire. That's fine. That's pure coffee. We're okay with that. But if a coffee producer who inherited the colonial crop wants to change the microbes with purpose and intention, all of a sudden it now becomes something that we need to label and. Rattle on about transparency and call it adulterated and think of it as an inferior product. I mean, Come on. In this sense, we already have adult traded coffee. When it was taken from Ethiopia, we changed its microbiome. So our baseline is adulterated coffee. This is not something new. That's happening to coffee. This is the history of coffee. This is how we got here. Anyway, this is a rare stance for me. You guys know that I love to be precise. You know, I wish there were more words to describe coffee, not less. I want a richer vocabulary. But in this case, the words, doctored or adulterated, I think those words, those labels, I don't think that they need to apply to coffee. I think there's a very, very limited use case for adulterated coffee in our conversations. Okay. But that's not the industry. That's not all I wanted to tell you about, because I want to zoom back now to Antioquia where Philippe was adding fruit to his coffee. Fermentations. He said he had mango fruits, which have a high sugar source to his coffee and he had a positive result. The cup was complex. And my guess is because the Manco provided so much sugar and other nutrients, other minerals to the existing microbes in the fermentation that it made for a really lively fermentation party. And let's not forget when adding other fruits, not only are you adding more sugar. To feed the existing microbes, but that fruit is bringing its own microbes with it as well. So you're double dosing. It's almost like the person who shows up to the party with a keg of beer. When most of the guests thought that they were out of alcohol, it's like a catalyst for a whole lot of other stuff to happen. And as we know, sometimes the after party is better than the party party. Anyway, and his infinite curiosity Philippe naturally thought, okay, I've added mango with a lot of sugar. What happens if I do the opposite. What happens if I add a fruit with low sugar and high acid. What is the opposite of a mango? I don't know, probably 11. And he wondered if I add citrus, can I get better acidity in my coffee? So Phillipa added a lot of citrus to the fermentation and during our live discord hangout, he asked me what I thought happened. At this point, I had never tried it myself. As you guys know, I don't have anything against adding fruit to a coffee tank. I just don't happen to do it myself because I worked directly with adding known strains of yeast and bacteria to get that transformation. But even though it's something I've never done, I was able to tell Philippe exactly what happened because of fundamentals. Philippe was the one who added citrus to his coffee. He fermented it, dried it and cupped it. I've never done any of those things, but when he asked me what I thought happened in an experiment that I've never done or tasted. I didn't even have to think about it. I immediately said. Probably nothing. And then he looked at me like I had performed a magic trick or read his mind. And then with a little disappointment in his voice, he said, yeah, it tasted like normal wash coffee. Meaning that for all that effort and expectation days of fermentation and drying, and finally getting to taste that cup. There was nothing. It was not different from anything else than his traditional methods. It didn't taste like there was any effort or difference in the process. Which was the opposite of the mango fermentation and the kombucha fermentation, which he had done previously and had great success with. So why did nothing happen? Or rather what happened that made it seem like nothing happened. First we already know the fruit flavors are usually not absorbed directly into the copy seeds. But his goal was not to get a citrus flavor. His goal was increased acidity. By adding the citrus. What he did was essentially dramatically lower the pH. In this, he was incredibly successful. When you start a coffee fermentation. They're usually the pH of the water that you use for pulping or the water that you use to move the coffee around. Because even if you don't do a submerged fermentation, it usually takes a lot of water to pull up the coffee and move it from one end of the mill to the other. Water, as we know, it's usually around seven pH, but pulped coffee is a bit acidic. So the fermentation starts around six or maybe pH 5.5. Mangoes have a pH of 5.8 to six. So adding mango to the coffee tank, shouldn't change the starting pH. However, the pH of lemon is too, even oranges that are much sweeter, still have a pH of three or four. And remember the pH scale is logarithmic. So pH two is 10 times more acidic than pH three. And if you're going from pH four to two, that's two units, but it's not just something as small as two units. It's 10 times 10, which is actually a hundred times more acidic. So if the mango fermentation started at 5.5 and the citrus one starts at 2.5. That's not a difference of three units. That's a difference of 1000. 10 times 10 times 10. The microbes in an environment are experiencing something that is 1000 times more acidic. Oftentimes we think we are making a little change, like a few degrees change in temperature or one or two pH units. But to the microbes, it's a tenfold change or a hundred fold or a thousand times difference. This is why so often coffee producers tell me that. I did the same thing. I'm doing all the same things, but my coffee comes out different almost every time. And this is a really common refrain because to our human senses, it does feel like we did the same thing. But on the micro level, you could have changed something very dramatically. And especially the producers that aren't monitoring their PHS, who aren't paying attention to this. Feel even more confused of what feels like the same thing, but can actually be an incredibly different result when we're talking on the scale of microbes. So it seems to us like maybe we're dropping a tiny pebble to a microbe can feel like dropping a Boulder. So you remember. P H and acid strength are opposite. Meaning the lower pH value means higher and stronger. The acid content. So Philippe added citrus not to get the flavor of citrus, but to lower the pH of the fermentation. This is actually very smart. And it's also a perfectly common way to preserve food. Check the label of many packaged foods and citric acid is often added as a preservative, lower pH food is a lot more stable and has a longer shelf life. So, okay. Philippe doesn't have citric acid powder, like most food manufacturers, but he does have a farm and he has access to a lot of citrus fruit. So he adds a citrus fruit to the tank. Another quick wine aside about this theme is that almost all commercial wine has this asset adjustment. We add acid to grape juice to bring the pH down and stabilize the wine for longterm storage. If you want to keep wine for five or 10 or 20 or 40 years, of course you want it to be stable and you adjust the pH by adding tartaric acid. This is incredibly common. Just like chapterization the practice of adding sugars. Wineries are not required to, to put this acid addition anywhere on their label. It's just considered good practices like sanitizing and washing your tanks. And you don't need to tell anyone about it. It's not something that you need to disclose and it's not adult trading the wine. It's just part of making a good and stable product. So once again, Philippe is acting like every other winemaker in France who adds sugar to the fermentation or every other wine maker in California who adds acid to their fermentation. There's not a call for transparency from winemakers for these simple additions, because they are trusted to know how to make their own product. And we are grateful to be able to drink French and California wines. Anyway. The first thing is that starting with a very low pH is a good way to control the fermentation. So when producers say they control pH because they have a pH meter and they measure the pH. That's not really controlling it. That's monitoring the fermentation. The Lee bay on the other hand, had a target pH in mind, he added the citrus. Lower the pH to 3.5 and then started the coffee fermentation. That is control. If you remember from episode 36, lactic acid, 1 0 1 controlling, the fermentation is like having security at your party. Only the invited microbes are allowed to enter. Lowering the pH means that you're basically setting the criteria for who are the VIP's that you're going to allow into your fermentation party. This is the opposite strategy. That most traditional coffee has, which is more of the microbial do mucilage donation, like the decomposition sort of the do nothing. And there's enough sugar there that the microbes that are in the environment and that are on the equipment will. In their own time breakdown the mucilage and you can wash the coffee. So it's a very functional form of approaching your coffee fermentation. And what we're talking about here with an asset adjustment. Is a very different form of, approaching your fermentation because having a very low pH having very high acid is also a high bar. It's D it's a demanding criteria. You are basically uninviting a lot of these microbes to your party. You're saying this is not an environment for you. And why is that? Why is low pH such a barrier? Well, it makes sense that it's a difficult environment to grow in. You can imagine the thermophilic bacteria that live in the boiling water of hot Springs. Or the cyanobacteria that live on glaciers, or perhaps you're a member of the halo tolerant bacteria that we talked about in the kombucha episode. So bacteria that are really resistant to high salt, high acid, high heat, or very cool temperatures. All of these create incredibly extreme environments. And while it's true that we still have some crazy extreme microbes that call these places home. By creating those environments, you are severely decreasing the population that's available. And severely decreasing the population on purpose is also a form of controlling your fermentation and getting reproducible results. And you might be confused because many coffee fermentations can have an ending pH of 3.5. And it's true. It's not a completely outrageous pH value. It's a very normal pH value in almost all coffee fermentation. But it is an outrageous pH value to start with. So many microbes as they grow and divide, they adapt to their environment. As they proceed with the fermentation, they themselves, by their byproducts are changing the environment. They are making the environment more acidic. And in the case with yeast, they are producing more alcohol with each subsequent generation. And the longer the fermentation is allowed to progress. The more difficult the environment becomes for the microbes. So in a way they're basically poisoning themselves, but they're also with each new generation creating defenses. So for example, most Saccharomyces service EA can tolerate alcohol to like a 16 to 17%. level. But that's about all the poison that they can handle. I think I have seen one strain that can tolerate up to 18% alcohol. And if you need to get an alcohol level higher than that for another beverage, then that's when you need to distill and concentrate the alcohol. So 16, 17% is really the limit that you can accomplish with a straight up fermentation without having to resort to other methods of, of distilling. So there is a limit. And while microbes can become more resistant to their environment, they need time for this resistance to develop. So a sacrifice, the ServiceNow needs to start with zero alcohol and slowly build up the tolerance over many generations, and then they get stronger. And then the alcohol is slowly building to 16, over 16%, over many days. But if you rehydrate brand new baby sacrifices and put them in a tank with 16% alcohol, most will immediately die. You can also think about it with that saying about putting a frog in cold water. And if you slowly turn up the temperature, it will acclimate to the heat and stay in the pot. And eventually. Boil alive. but if you do the opposite, if you try to put a frog in boiling water, it will do its best to jump out. I know it's a gross image, but it's essentially what's happening to the microbes. In the citrus acidified environment. They didn't have time to acclimate and many cannot live and grow in that environment. So the either go dormant. Die immediately or never even get invited to the party. And like I mentioned earlier, there are microbes who thrive in extreme conditions. So it's not like you're completely sanitizing and killing everything and have absolutely no fermentation. It's just that there are fewer of the extreme microbes. So you have less diversity, which, you know, sounds like a bad thing. We like diversity. But when it comes to producing consistent coffee, fermentations with a consistent flavor profile, less diversity in your fermentation tank can be a good thing for that repeatability. Lack of micro diversity means you can have more predictable results and then you can reproduce those results. And then that allows you to scale those results from. Dealing with nano and micro lots to then transfer that information or transfer those results into tons and tons of containers of good, consistent coffee. I mentioned the low pH meaning high acid made a very extreme environment that very few microbes can survive. So Philippe basically rented a big hall decorated with balloons, bought a bunch of food. Got an expensive sound system to play dance music. And by adding citrus, it was like he put a bouncer at the door and told everyone to go home. No one was allowed to come in. It was an empty house party. And remember previously Philippe did a kombucha fermentation. And after that fermentation, when he cut the coffee, he had an explosion of flavors and the coffee. So first there was a micro party in the fermentation tank, and then there was a flavor party in his mouth. And this interest process, he was expecting something like what happened last time. But when he dried the copy and cupped it, it tasted like no one had been at the party. I don't remember exactly how long the citrus fermentation was, but I know that it was several days. And yet another mystery. In his mind, he threw a party for many days, but it didn't taste like it. Fermenting coffee for several days usually has some dramatic effect on flavor. And yet this didn't. This gives us a clue that little to no fermentation activity happened because we don't have the proof of fermentation. The flavor is approved. That's something happened. But this leads to a second mystery. If you're a regular listener to this podcast, you know that one of the problems we've had in communicating is that the traditional role. and the way to talk about fermentation was about removing the mucilage and wash coffees, not about flavor development and adding value. Second step E in remove. And have any of the mucilage epi. If there was little Ergin B COFA flavor, but we all the fermentation or you to remove. And we bet all that. Mucilage. In there. What. Proof of. Well, it could not have been because their roof or their, is that the On YouTube sometimes. magazine and. The FICO complicate and. then explain it. Uh, picks includes each genetic and music theater, but my feature recently astrophysicists in PhD, gravity at multi levels in the video gravity. A child than a high school is college It's apt, but also. The meaning. Gravity pool, falling to the, throw something in gravity and gets pulled back. Gravity's And for a college do faces. Curve is a field space and same as flooding. Well, good. That must come down a longer. True in college can reach us and never come back. Even though they say they are both at levels. For a graph. Gravity is about ours and we're Lycoming