Eric Dixon

Eric Dixon joined Lallemand as the Midwest technical sales manager in 2018 after working in the brewing industry for several years at breweries all around the USA. Originally from Delaware and now living in Chicago IL. He’s a graduate of Siebel Institute of Technology. An avid hiker and lover of all things. outdoors.

Pablo Gomez

Pablo Gomez is the Southeast & Latin America Technical Account Manager for White Labs, based in Asheville, North Carolina.

Marcelo G. Cerdán, Ph. D.

Marcelo G. Cerdán, Ph. D.Marcelo G. Cerdán, Ph. D. joined Fermentis by Lesaffre in 2007 as Sales Manager for Latin America, and in 2013 he took the role of Sales Director for all the Americas. At Fermentis, he developed yeast sales, yeast derivatives, and fermentation solutions in all fermented beverage industry segments. He also contributed to several R & D projects in the region and organized training activities in the industry.







Key Points From This Episode:

  • Introducing Pablo, Eric, and Marcelo, three yeast experts, and today’s guests.

  • Each guest gives a brief snapshot of their background.

  • Debunking myths about dry yeast.

  • Why dry yeast is a popular choice for so many brewers.

  • The difference between propagation and fermentation of yeast.

  • Why quality control is so important when it comes to responsible propagation.

  • How co-fermentation and blending strains can be a quick and easy way to diversify flavor.

  • How to overcome issues associated with yeast blends.

  • Different innovations that have aided our guest’s fermentation processes.

  • Advice for veteran brewers with high-tech equipment, and newcomers still green to brewing.

  • Hear about the best practices you can perform in your lab.

Transcript - Yeast Buds




Host: Tim Roberts, Country Malt Group

Guest: Marcelo Cerdán, Fermentis

Guest: Pablo Gomez, White Labs

Guest: Eric Dixon, Lallemand


[00:00:12] TR: Hey, everyone. This is Tim Roberts, and I’m with Country Malt Group on the Territory Manager in Pennsylvania, New Jersey. And in this episode of the Brew Deck, we’re super, super happy to have three yeast experts that represent a huge segment of the business in the US. And I think it’s best to kind of just let these guys introduce themselves. So, take it away.


[00:00:32] MC: Hi. I will start. My name is Marcelo Cerdán. I work for Fermentis since 2007. I am based in Miami, Florida since 2015. And I am a Ph.D. in biology, molecular biology exactly. During my Ph.D. I discovered beer and industrial fermentations and really became my passion, beer on the top of the list. And then I was working with [inaudible 00:00:59] industry since 1999 as a consultant, educator, brewer, founder of a brewery since 2007 with Fermentis. That’s a little bit of myself.


[00:01:08] PG:  I’m Pablo Gomez. I’m technical account manager for White Labs. I’m based in Asheville, North Carolina where we, I guess, three years ago, almost four years ago, we opened a lab. And since I started brewing long, long time ago, I always got connected with fermentation. There was not a lot of information held there, and I kind of like have to figure out on myself how to make better beer. And when I, noticed, when I started like I figured out that fermentation was the most important part, then I got hooked.


My little background, I’ve been working for the Cicerone Program, helping developing the Spanish program for Cicerone. I’m currently the Spanish editor for the Zymurgy Magazine, the American Homebrewer Association. Yeah, that’s kind of like a little bit of background for me.


[00:02:08] ED:  my name is Eric Dixon. I’m with Lallemand. I’m based out of Chicago. I’ve been with Lallemand for a few years now with my background primarily in brewing. Before that I was kind of looking to do something different within the industry, and that’s when I came across Lallemand, and that’s been pretty good so far.


[00:02:27] TR: Great. Well, obviously, as you said, we have a whole lot of knowledge about yeast and fermentations and everything. So let’s get started with it was sort of me taking a visit back to my early career and talking about dried versus liquid, because I was always taught that when you bought dried yeast, you couldn’t re-pitch it. And I think that’s sort of been something that’s either been changed or debunked and maybe a little entry into talking dried versus liquid.


[00:02:55] PG: Yeah. It’s two versus one here. Let’s –


[00:02:58] MC: Two versus one, yes. I can start if you want. But I remember those days. This is not about dry east technology, it’s about the know-how of the companies that are drying yeast. And, no. I think dry yeast technology works. I think the products you have in the market today is really, really good. That was proved before those times. The problem is that when you produce beer yeast or you dry yeast for beer, you need to consider a couple of things, which are very important. Quality is different. So you cannot put bread yeast to produce beer. We can produce beer, but then the risk is very high because you have some other quality needs for beer. So it’s completely different.


That was taken in consideration. The situation changed a lot, and that happened probably more than 15 years ago. That’s basically what we can say. But today, for us, from the perspective of Fermentis, the quality is very important. It’s one of the top priorities. And we are continuously improving quality and working on that. We have R&D programs to improve our quality, the quality of our products. And today you can rely on these products. So today if you start with liquid yeast, dry yeast, you can of course recycle these. You can harvest these and grow to the next fermentation. You need to obviously to take care of liquid yeast with the cleaning process. So you need to clean, like you clean always your brewery. But today it’s more improved a lot, a lot, a lot. Today those are really reliable products.


[00:04:40] TR: And, Pablo, you’ll get your chance. But, Eric, maybe you want to chime in on exactly what changed in terms of the improvement and quality that allows us to re-pitch dried yeast now.


[00:04:51] ED: I think, well, certainly what Marcelo was saying, I think a lot of the technology has come a long way. I think brewers wanted a better product, and that’s what was offered them over time. We’re doing 24 tests on all our batches of yeast to confirm purity and genetics before they get out the door, which is something we weren’t doing 30 years ago.


[00:05:13] TR: Yeah. And it’s my understanding that just the amount of sterols that are able to remain in the drying process is also just a huge aid. And so for the counterpoint, Pablo, what do you have to say about dried versus liquid?


[00:05:29] PG: I totally agree with both of them. I think that dry yeast, that dramatically improved in the past I would say what? Five, ten years? Yeah, I think right now it’s a great product. It’s different than liquid. That’s what I would say. There’s a difference, and you can see it, right? The price is different. Shelf life is different. Dry and liquid, they have the pros and the cons. Personally, I think that in the sensory perspective there is a difference. Like [inaudible 00:06:05] many of sensory panels and stuff with dry yeast versus liquid, with same wart, same everything. And I always – Personally, I always get the difference, and it makes sense, right? I’m not saying one better than the other one, but I’m saying both have pros and cons. But liquid yeast is more expensive. Liquid yeast has a shorter shelf life. It’s more difficult to transport, right? Those are the cons of liquid, but why it’s still more expensive?


And I think it’s a little bit for me on the sensory side of things. We produced yeast basically daily. The freshness of the liquid yeast, I think it makes a difference in the final product. But I think both products, both have pros and cons and it’s up to the brewer what it’s looking for.


[00:07:04] TR: Yeah. I mean I concur. There are definitely pros and cons in both. But we all certainly agree that yeast is just profoundly important in the production of quality beer. And in fact I have friends that refer to themselves and I know brewers that refer to themselves as yeast farmers. And so the idea of farming of course is growing up stuff. And so when we get the sample or the dried yeast or the liquid culture into the brewery, sometimes we pitch it right away and sometimes we propagate it. And I’m wondering if you guys, especially for some of the newer guys out there, would like to discuss about the difference between propagation and fermentation and maybe even offer some tips.


[00:07:44] PG: I think one of the things I see sometimes in the industry, people tends to think that propagation and growing yeast by fermentation, by fermenting yeast, is the same, and it’s not the same. Very few breweries have the right equipment to properly propagate yeast, right? So you can grow yeast by fermenting it, right? But it’s not the same as the propagation a lab will do, right? When a lab propagates yeast, it’s looking for biomass. It’s growing yeast not going through basically fermentation. Very minimal fermentation depending on how you propagate, right? I think dry yeast propagates differently than labs than propagate liquid.


But besides that, I don’t know. Let me tell you some of the differences. Like a lab will propagate yeast with sterile [inaudible 00:08:38] water will use a lot more nutrients than brewer will use. It will be constantly aeration, oxygenating the yeast so the yeast can grow and create more biomass. So those big differences. And yes, there are ways to grow yeast a little bit in the brewery, but I want to just to make sure that people understand the difference between a propagation per se and growing more yeast, growing the cell count a little bit by fermenting.


[00:09:12] MC: Yeah. I agree. I take one word that Pablo said about the biomass production. So I understand propagation as the production of biomass. So you have different ways to do that, okay? In fact, you can do. You can produce biomass in fully anaerobic conditions with symbol to fermentation, but this is not good. Then you have to go through [inaudible 00:09:34] fermentation process. There are some issues, okay? Then you can have an aerobic batch propagation. Then you can have a fed batch propagation where you add sugar sequentially and you take advantage of the Crabtree effect. When we grow yeast in the plants, we add sugars in a way that we keep the concentration of sugars very low. And then when you put oxygen, these does not produce ethanol. This is a very, very good way to produce biomass, because you don’t produce alcohol. All the sugars are used to produce biomass.


However, there are some other things you need to consider at contamination, for example. You need to have very strict conditions. I think it’s extremely important that propagation is something that the industry is doing. It’s something very valid. It’s something that breweries can do. But it’s very important to do in a proper way. I mean, it’s important to have all the equipment to do right propagation to have quality control, because you can propagate bacteria, for example. If you don’t do it properly, you can propagate bacteria as you propagate yeast and then you will have an issue with the fermentation. That’s basically what I can say. So propagation could be very risky if you don’t have the right elements or quality control process. And that’s something complicated for small breweries today. So it’s because you need to invest in people, technology, and that’s really complicated. That’s why you also see more propagation in bigger plants today.


[00:11:11] TR: Well, yeah, for sure. I mean, obviously, there’s a cost, an investment aspect to it. But Pablo actually said something that I thought was interesting that there’s a difference in how liquid culture and dry yeast are propagated. And I wonder if you can say a few words on that, Eric.


[00:11:27] ED: The biggest difference in the propagation of those two is the sugar source. So liquid, of course, being grown with wart and then the dry yeast, for us in Lallemand, is done with molasses. That’s the real, real difference. We use fed bash, which I think is what Fermentis uses as well, forced air and some nutrient just to get things off the ground.


[00:11:48] TR: Yeah. Agreed. I mean I think Pablo, what people could take away is the fundamental differences are the incremental or periodic condition of both air or oxygen and sugar, right?


[00:12:00] ED: Yeah. And it was interesting something that Pablo brought up a little while about the sensor in the final beer. And we’ve talked a little bit about that before, and I guess it comes down to how that yeast is grown. I personally can’t tell the difference, but some people can.


[00:12:14] MC: Yeah, there’s a big debate. And obviously I listen that very often, but we don’t see really differences, because of course we do our internal research and we really don’t see differences when we propagate and recreate. Because of course we compare with our own strains. So we can propagate and we can compare with dry yeast, and we don’t see really differences in terms of – But of course I know there are different opinions and there are different perceptions about that.


[00:12:45] TR: It’s strain dependable too. There’s some strains that are harder to find a difference and then other ones, they’re kind of more obvious, I guess, if I will add something to it.


[00:12:59] MC: Yeah. Something it’s important [inaudible 00:13:01] what you’re saying, Pablo, is that not all these strains can be dried successfully, okay? The decision to put one strain to market that you don’t has low viability. That’s very important, because then you would see differences, okay? So that’s part of the quality program of the company you’re working for. So I suppose Lallemand has the same idea. So we don’t put in the market strains that we believe that do not perform very well, because the drying process is not successful.


[00:13:32] ED: Yeah. We have that same hurdle where we got to beat that trailos and sterol minimum before we can even dry, or the cells just fall apart.


[00:13:39] TR: Well, yeah, for sure. Like you guys alluded to. I mean I think there’s some of these standard strains out there like chico or fullers or the common names that you want to call them and all you guys have versions of them, but I know from a brewing standpoint, when you start talking about flavors, know I do believe that there are subtle differences from one yeast bank or one producer to another. And I think we’re talking about yeasts, of course, and they’ve been around absolutely forever, some of the basics of life. And lately there’s been a real, at least for my way of thinking, or maybe I’m just more aware of it, is that there’s been a real proliferation of yeast strains. And I’m wondering if you guys have thoughts on the idea that you’re trying to give maybe brewers another arrow in their quiver by propagating a new yeast or supporting a new yeast and/or isolating a new yeast. And I think that’s kind of something that’s been interesting, but that’s also happened I think probably most notably in the hop producer segment.


[00:14:37] MC: Brewers are crazy. Sorry about that. I love brewers, because they are so innovative and they push us to look for new things in the market. But also if you look since 2012 or maybe before, there are so many words about taxonomy. In fact I think why labs participated in some of them, just to understand the beer diversity. It’s amazing what we have there, okay?


Of course, point of view of a dry yeast producer, we cannot produce all strains in dry. But we try to look for very – For strains that are really representative of the different groups. And then of course we have new challenges every day. We have a huge R&D program trying to understand different easy strains and trying to identify different easy strains and then try to look for the best representative of these groups. That’s our approach.


Of course, one of the – I have to say, I have to recognize that one of the big advantages of liquid yeast is that we can put in the market a lot of diversity, okay? [inaudible 00:15:49], but I think we have a quite good representation of the different groups of beer yeasts.


[00:15:59] TR: It’s an interesting topic, because I guess it depends how adventurous you are. Some lab and some parts of the world, and they’re already playing with modifying the – Genetic modified yeast. There’re some labs that are playing with hybrids. It’s all respectable. Everybody has their own opinions. I love science, so it kind of excites me all that. But at the same time, one of the things that I like the most about brewing, I like the science of course, but I like the art side of brewing, right?


So I think if suddenly everything starts like being genetically modified and I create this amazing yeast and can – I don’t know, do whatever. Interact perfectly with mosaic hops and sour at the same time and whatever you want to call it, it sounds exciting. But I think it will lose some of this art, right? So in my opinion, I think that blends are a good answer right now. I don’t think like brewers have been explored. For a while I’ve been doing some recently work on blending different organisms, microorganisms to create something cool. And not modifying anything, doing a hybrid and something crazy in a lab. You just blend in different strains or different microorganisms and you get a different type of beer.


So I think that there’s a lot of things then can – If you want to get something a little different, I would encourage brewers to start like blending not just like 50% of this and this. Use three different strains or use different amounts of yeast or mix it with another microorganism. Mix it with bread or like with wild yes or bread or mix it with a bacteria, whatever it is. And I think there’s a lot of room there for kind of creating different new flavors or things.


[00:18:10] MC: Yeah. I think there is a lot of diversity out there still. We need to learn a lot about – In fact, Kveik is one case. Nobody was talking about this group of strains and cultures in the past. It’s something new. It’s coming.


I agree. So you have hybrids. we are discovering new hybrids very often right now. So the most famous case is the case of lagrangian strains and saccharomyces pasteurianus. But now we know there are some other hybrids that are frequent in the beer industry. [inaudible 00:18:47] are also hybrids, and that generates a lot of diversity. Also, blends, as Pablo is saying, it’s a really, really, really wonderful tool as well. It’s more difficult obviously to know the behavior of these cultures when you mix them. But of course, I think brewers have a lot to play, a lot of beautiful things to play.


[00:19:08] ED: I love the idea of co-fermentation and blending strains. I think it’s a great way to add complexity and new flavors and things in a really quick, easy way. As for innovation, we love innovation. At Lallemand, it’s core to who we are. And I think we’re really just starting to hit a stride where we’re really starting to – We had four strains, new strains this year. And I think we’re really happy with where things are going.


[00:19:32] TR: Well, yeah. And I think as Pablo alluded to, the Clark yeast, which was isolated in rural Scandinavia. And I’d say in my travels around visiting brewers and stuff, I’d say that’s probably the most talked-about strain recently with the idea – People talk about the flavor, for sure. But I think sort of the main attributes of it are that the really hot fermentations, which of course really speed things up. And I’m wondering do guys all carry a Kveik?


[00:19:59] ED: We have uh our Voss and we also have a few others that we’ll be coming out with over the next coming years.


[00:20:06] TR: How about you guys, Pablo and Marcelo?


[00:20:08] MC: . No, we don’t. We currently don’t have in our portfolio. Of course, this is an important topic for us. We have an [inaudible 00:20:14] program as I said before, and we are working to select new strains, and of course, Kveik are part of that. One of the most difficult things with Kveik streams is that most of them are blends. And we still need to learn a lot, a lot. That’s one of the most difficult things we can see today. So it’s well-documented. So most of the cultures are blends today, and of course, we have some of them that are not. But it requires a lot of research yet.


[00:20:43] TR: Sure. And I’m sitting here listening to you guys. Obviously, you guys know a lot more about yeast than I do, but as a brewer, to me using blends was always potentially problematic, because they don’t drop at the same rate. And so when you would harvest them, you’d get a different percentage. And if you guys are sort of packaging plans, is there a way you kind of overcome that issue?


[00:21:06] PG: I would say that that’s the only con maybe you can have from blends. Like it depends on the strain blend if you’re going to be reusing yeast if you’re going to be harvesting that yeast, it will eventually change, right? One stream stronger, right? Always going to take over. Forget about if in the blend you have any Belgian strain. That will take over pretty fast. I guess that’s the thing. If you want consistency, maybe reusing a blend is not the best idea. But I’ve seen cases of brewers reusing blends and suddenly on generation three or four, the blend became even better than what it was at the beginning, right? Like I said, it depends on what type of brewery you have. What are you looking for?


I see blends and stuff as a more adventurous type of brewers. Maybe if you have more like classic and you’re probably not even interested on a blend or something or anything new. You want to do classic things and beers or using yeast then you kind of like know what they’re going to do, right? On blends, it could be a little – Of course, coming from the lab, it will act the way it should or what the lab intended. But then once you start harvesting and reusing it, it might change for good or for bad.


[00:22:40] MC: In the past, many breweries were using blend, and they probably didn’t know about that. So those were cultures that were well-established, okay? Stabilized, we can say. What Pablo say is true. So when you have the first generation with a blend, so there are interactions between the strains, different kinetics. So one easy strain taking over the other one.


One of the things we recommend when brewers do some blend is to take a look at the kinetics and see if you have a very aggressive yeast or another one with – If you put together with another one, which along that phase, that aggressive strain may take over the fermentation. So you will probably not see any effect of the other one. And then you have to play with the rate, the ratio. So there are some things, some tools you may have, you can use before defining the blend. But then when you finish the first generation, that could be completely different. So the ratio could be completely different. Then the [inaudible 00:23:47], segmentation is different. So you may have one strain more prevailing than the other in a different ration. And then at some point, those cultures may be stabilized, but you don’t know when you reach there. As Pablo said, I think it’s not very easy to keep that culture going if you want to have consistency.


[00:24:10] ED: When we first started looking at [inaudible 00:24:11] all the samples that we got were blends, and they were pretty big blends. I think they were like nine to ten different strains. And going through those we just sequenced them out and found the dominant strain in that blend and just did some more test on that strain. That’s how we came up with the products we’re making now.


[00:24:29] TR: Yeah. That’s interesting. I was lucky enough to be visiting a brewery in England and was talking to the brewmaster and it was a fairly sizable one who had run into a yeast problem in the 50s. And they borrowed some yeast from the brewery down the road and then just kind of forgot about it. Got more of their yeast and – But what had happened is they had both taken hold in the brewery and like 70 years later they existed after they took it to the lab in the brewery samples at almost exactly 50-50 blend after 70 years. So obviously an example of two evenly matched strains. I just thought it was a pretty phenomenal story.


[00:25:09] PG: Yeah.


[00:25:12] TR: Yeah. It’s strange. I guess I should not name names, but maybe when we’re down here, I’ll tell you about that a little bit more detail. We’re talking a lot about innovation in terms of flavor, and I think for the brewer, that’s probably ultimately for most of us, it’s what drives us to – Gives us the passion for brewing great beers, of course, the flavor. But there are serious processing questions for yeast that, for example [inaudible 00:25:37] rather ferments so quickly. And I’m wondering what role in innovation, just sort of processing advantages play for you guys.


[00:25:46] PG: During the pandemic, one of the things I needed to get myself busy. So I went to our bank and I identify all the different Kveiks trains we had in there. And I started doing trials with six different Kveik strains. Right now we have four available [inaudible 00:26:10], Sigmund, which is the Voss, known as Voss. We have Stranda and then we have [inaudible 00:26:15].


It’s interesting. What I found is it’s basically what is interesting about Kveik is not that it can’t ferment at those hotter temperatures. Any strain can ferment at 90 degrees. Now, is any strain going to make good beer? No. Right? It’s going to be full of fusal alcohol, esters and name it, right? But these Kveiks were able to ferment at those temperatures, which the hotter the temperature, the faster. That’s the whole secret, right? It’s not under any special that they ferment fast because they have some specific gene. No. They ferment fats because you fermented it at 90 degrees, 90, 95, right? That’s why they ferment so fast.


The secret I think they have, and it’s not really a secret. I got a theory. Well, it’s not that I created, but by talking to people, talking with [inaudible 00:27:13], which is kind of like the guy behind all this. The point is like these Kveik strains can keep it cool at those hotter temperatures. They don’t produce a lot of this crazy amount of esters on any other strain can produce at that temperature. But they’re all different, right? That’s why we decided – last year we have only one strain out and, and this year we released three more after this research, after these trials, because we’ve seen different characteristics in these strains. It’s very interesting what’s going on with the Kveiks and why they can ferment that clean, let’s say, at those hot temperatures.


[00:28:02] MC: I agree. This is really interesting, but sometimes – The other day I was – just one story. I was talking about [inaudible 00:28:13] where we were presenting about a couple of strains that we recommend, and that was a conclusion in a really important R&D program. There’s a question that is coming very often. Can we do it with Kveik? I don’t know. People, they put a lot of expectations in these new strains. But I believe that today we still have a lot of diversity out there. And Kveik will be incorporated in the brewing process more often. But at the end of the day will be a new tool, something new for the brewers. But I don’t think it will essentially change the process for the breweries. That’s my personal opinion. I think it’s something more, something else really nice. But I don’t think it will change the things too much.


Another thing, for example, talking about temperature. We have another strain that normally – Of course, you know, [inaudible 00:29:11] ferment between at very low temperatures, but you know after some work, some application tests, that that strain performed very well at high temperatures and you can have a very nice lager fermentation at 68 degrees Fahrenheit, for example. Those are things we are discovering every day when we do more and more research, okay? And we are telling people, you can produce a lager at 68 Fahrenheit. People, they look at us and say, “Okay, that’s not possible.” Yes, it’s possible. So we show that about that.


So we are discovering new things every, every, every single day. Everybody, not Fermentis, because of course there is a lot of research going on there. And Kveik I think it’s part of the innovation, but not the solution. I think it’s something else that will do to beers, something we’ll reach. You will have one more option. That’s my perception.


[00:30:07] ED: I think that versatility is tremendous you know. Especially in brewing, to sit down and see people make stouts and IPAs and sours and all from the same kind of yeast is really incredible. They’re all kind of flavorful and good. So I think that’s huge.


[00:30:23] PG: Yeah. One thing I found at least on one strain, the Hornindal. It’s our WLP521. It’s that it’s high in and producing glycerol. And glycerol can give you a contribute to a body perception, kind of like more sweetness type of thing. So I found that when brewing like say a New England IPA, that was kind of one of my favorite. And I was wondering why. And then by doing research we found that. And I think that’s a good tool to use. That’s kind of why you’re looking in a New England IPA. But yeah, there’s a lot of more research to be done. These trains were used to ferment totally different beers in Norway than what brewers are using it for here.


I heard people brewing lagers with Kveik, right? By starting the fermentation on lower temperatures and then when reaching 50 attenuation or so, then raising the temp to the 30 Celsius, 90 something Fahrenheit, and having good result. I don’t know. I haven’t tasted it. What I like about it is like there’s more to do about it, and it’s kind of exciting.


[00:31:48] ED: Norwegian Hard Seltzer.


[00:31:53] PG: Yeah.


[00:31:53] TR: Yeah. I mean, and like you guys are talking about, I mean there’s sort of – There’re a couple tandem questions there. There’s a flavor of yeast obviously, but then there’s also performance. And like you guys have alluded to also that there’s been an explosion of breweries in this country obviously in the past decade or so. And I’m wondering if you guys have any tips for either the more experienced brewers that have access to nice propagation equipment and yeast storage and harvesting and/or the new guys that are really sort of first trying to approach the problem of getting the right number of cells and the right amount of work that has the right strength and the right aeration. So I guess my question sort of hinges around propagation and storage for the bigger guys or the guys with a little more resources and sort of first steps on making a consistent beer for the new guys.


[00:32:45] MC: When you talk about small breweries, you can see that all the top zones you have in the US today, it’s really amazing. So the diversity of beer is amazing. And I think also the yeast probably in the past was [inaudible 00:33:00] were trying to work with what single culture and try to produce as much as beer as they can with that culture. But now most of these breweries are looking for more diversity coming from yeasts. Like you select hobs and malts, brewers are starting or they already started to select easy strains to produce specific styles, okay? And then you can imagine today that you have in one single brewery, maybe one brewer using 10 different kind of yeasts, I think. How do you manage propagation? How do you manage the cultures in this case, okay? I think it’s at some point you need to decide, “Okay, if you want to have diversity coming from yeasts or you want to have your own culture and then propagate and then recycle and then keep that culture in very good shape. And that’s where probably dry yeast could be a solution also because you avoid propagation. You can go directly into fermentation. For those small breweries, it’s a real solution.


At some point what brewers cannot do is to play in probably all the spaces. You cannot propagate, recycle, and then use 10 strains in the same brewery when you have a very, very small brewery. That’s something very difficult, and that’s creating a lot of problems. And then you have diastatic of yeast. A lot of things that you need to manage and you increase the complexity when you use a lot of strains. So when you have the possibility to simplify your life. I mean, if you just pitch, you use hops like you use yeast and malt, it’s really very easy, okay? So sometimes you cannot do everything. And then brewers needs to make a decision at some point where they want to go.


[00:34:44] ED: Buy a good microscope. A real good –


[00:34:50] TR: I mean, like, Marcelo, you were saying. To me, it is always a question of investment and equipment and what you’re able to do. But I do agree the dry yeast, that kind of gives you a little bit of flexibility. And at least for the first generation a little bit of – Like you know what you’re pitching for sure. I don’t know what your thoughts on that are, Eric.


[00:35:11] ED: I agree with that. I think when you want to get into re-pitching, I think learning about yeast nutrition is important. Making sure you have enough oxygen, dissolve oxygen [inaudible 00:35:20] nitrogen, things like that. Really help when you get on a generation four, five, six. When you keep going down the line, you want to make sure that your yeast is able to perform. Having that microscope gives you a better way to get some cell counts, staining. Those are all important things.


[00:35:35] TF: Yeah, absolutely. And not much of an investment. Marcel, you mentioned diastatics, which is of course like Kveik. It’s in the news a lot, and there are devices that you can buy in your brewery like the Paul-Jean disc and the Brew Pal, and then there’re services like Invisible Sentinel. And then of course there are strains that are diastatic as strains even though it strains, the peace of mind of the brewer to brew that into – To bring that into the brewery. But I’m wondering if you guys think – What are your thoughts on the topic, I guess? I guess, Pablo, I’d throw that to you to start.


[00:36:14] PG: Yeah. Well, diastatic has been in the industry forever, right? Like any [inaudible 00:36:20] strain, any Belgian strain will [inaudible 00:36:23] positive. The thing is, like Marcelo said earlier, before, long time ago brewers were using only one strain in the breweries, right? So an English brewery will never have [inaudible 00:36:41] strain in the brewery.


So I guess that’s what – Before people drink fresher beer, right? They will just make a beer for their taproom and drink it. Now there’s distribution. Now you send them beer across the country. You send beer to a different country. So diastatic thing became a little more relevant with the modern type of brewing industry. You find diastatic as in grain, right? So cleaning is another big thing. Diastatic was always around us, but now it became a more important topic.


[00:37:25] TF: Well, I think coupled with the PCR detection.


[00:37:29] MC: I have experience with PCR, because that was something that I was using during my Ph.D. But it can give you an opinion about the tools you have today in the market because to be honest, I don’t have experience on this kind of tools. But a PCR, obviously, it’s a tool that brewers have today to detect the presence of the SDA gene, okay? Which determines the potential for over-attenuation, okay? But also it’s just a potential because you don’t know how if you detect the SDA gene, it doesn’t mean you will get over-attenuation.


Today one of the things that it’s important to talk about is about the accessibility of these tests, okay? And that’s something that we have to put focus a lot in our plans. So we have developed specific tools, those are proprietary tools to detect the presence of diastatic strains. And in fact, we have involved the external labs for that. But today we are not using the tools that the industry is using. So we have our own development and we had to look for a better sensitivity of these techniques. So we need to provide to the market very product that it’s safe so and that’s the reason we have to look for that. But it’s something that from the producer perspective we are really taking care. It is very important for us.


[00:38:56] TR: Yeah. Well, man. These days we’re sure talking a lot about sensitivity and testing, huh? Eric, I think you were the one that said the word that indicated the elephant in the room here. And I think uh you all know where I’m going with this, is seltzers. I’ve asked questions about seltzer fermentation and yeast nutrients all the time. And I’m sure we could talk all day about it. But I don’t know. Do you have any advice for brewers that are starting to dip their toes in that water?


[00:39:25] ED: Strain selection is important. Make sure you have a strain that can handle that kind of stressful fermentation. Nutrient is a real big important thing to monitor. I mean you’re basically trying to ferment something that has no nutrient. It’s important to buffer the PH of the solution. Because as that ferment fermentation goes, you end up dropping PH, and then your fermentation stalls out. But that’s my two big pieces of advice. Get a good nutrient. I don’t like really the nutrient blends. They sometimes can have a lot of zinc. And then once you get to the level of nitrogen you need, the zinc is poisonous. So you can really get all those products on your own and formulate your own blend that really works. I also think optimizing that process is a smart thing too. Do it a few times and measure some of those results and really start to look at what’s really happening.


[00:40:15] PG: Yeah, I agree. Seltzers, they seemed like something really easy. And then people were calling having a lot of issues. Like brewers were like, “Yeah, I brew beer. I can easily brew a seltzer,” and they were having a lot of trouble. And it’s basically because, like Eric said, like it’s just pure sugars, just glucose. Has no nutrients, no anything. So yeast will struggle.


So we developed a new nutrient called seltzer max that we kind of like look into what it was needed to have a good fermentation, like, of course, nitrogen, vitamins, minerals. So when this started, everybody was kind of like not knowing what was going on, right? And another thing that I believe that’s important is like the healthy yeast, the pitch rate, right? Since it’s going to be hard for yeasts – Pitch a good amount of yeast.


And the other thing is a little bit outside fermentation, is the expectations of the brewer, right? Because they all used to drink this – I don’t know if I can say the name of the brand, but let’s say the most famous one, right? And they all look like crystal clear, perfect. Well, for a craft brewer, that’s very difficult to do. These companies who make this most famous hard seltzer waters, they probably have filtration system the size of the craft brewery. When you’re a craft brewer and you don’t have filtration system, it’s difficult to make this crystal clear. It will look pretty good, but it’s very difficult to get to that point. And I want to mention that, because if you as a brewer, craft brewer, trying to make a seltzer, you should know about that and then do the best you can to make it look the best way possible because that’s another thing. Some people are calling, “Oh, it kind of look a little hazy or kind of look this and that.” That hard seltzer water was introduced and produced by a massive company with a lot of equipment that the craft brewers mostly don’t have.


[00:42:41] MC: Yeah. I think if I can add something. As they say, it’s very easy to mix water and sugar. The problem is then to ferment. But I think the fermentation step is essential here because if you have a healthy fermentation, then your product will be clean and maybe you don’t have to work a lot downstream, okay? So basically you need to provide nutrition, that means vitamins, minerals, nitrogen. Then you have also to work on the buffer capacity. That’s very important. And then also if you produce high gravity, you have the possibility to dilute also and to dilute a lot of volatiles, okay?


So today I think we have also recently launched this year. It was product, the name is Spring [inaudible 00:43:31]. It’s a quite complex mix of nutrients and we provide everything they need to ferment. Also, there are different fermentation strategies you can follow. You can, for example, add the sugar sequentially to decrease the osmotic pressure. We can add some oxygen at specific times of the fermentation. So there are different fermentation strategies you can follow to achieve a healthy fermentation, and then that means that you will get a product, which is more clean and less downstream processing. That’s very important. Of course, it’s a challenge. It’s a challenge for us. We are all understanding how to be more efficient to ferment this kind of substrates.


[00:44:20] TR: Well, yeah. And kind of like you were saying. What I talk about is that it probably has more in common with brewing than you think. You’ve eliminated work, which is obviously one of the big building blocks. And so if you guys, I think the brewer necessarily has to put a lot of faith in your companies. And I’m just wondering if you could all talk about sort of best practices in your lab or maybe just reassure us all that you guys are sending us a microbiologically pure and viable product.


[00:44:53] MC: We have specific specifications, okay? Those are very strict. And we are improving. I think today the specifications of the dry yeast you have in the market are exceptional for the beer process. Of course, we have some partnerships with external labs for specific things. But especially quality for us is the most important, probably the most important point. We want to bring the best quality to the brewers, the best quality we can. And today we are really happy about what we are supplying to the market.


Concerning to practices, I think it’s in the brewery. I think quality could be good, bad, whatever. But you can’t have the best quality. But if you don’t have the best clean process, you will have issues, okay? With liquid ease, with [inaudible 00:45:41], with everything. And I think that’s very clear for the brewers. But sometimes it’s good to say that.


Also, something which is important, we were talking about diversity and all these kind of new beers where you put a lot of hops, chocolate. You put a lot of ingredients. You can imagine that everything is bringing different stuff to the fermentation, okay? So when you do these kind of things, you have to assume as a brewer, you have to assume some risks, okay? And it means that at some point you need to sit down, think what you’re doing and to implement very good quality procedures, identify the risks. Those are basically the things we can tell brewers. But the other message is we are doing the best in terms of quality to ensure that you have a reliable product. That’s the message I can bring to them.


[00:46:34] TR: Yeah, I agree. That’s super important. We have a process of 17 to 21 days that it takes for us to propagate yeast. Our system consists on like, once we start growing, always, every lot, every batch starts from an initial culture. Meaning coming from this cryogenic freezer. And then we assign a lot number from the beginning. And every step of the way on those 17 to 21 days, we scan every checkpoint, every QA, QC point, can it. And some of that information, for brewers, they can see it by going online on yeastman.com. The [inaudible 00:47:20] report of every single lot is there and we kind of created like some sort of like traceability type of a system where we can go back or forward, back and forth and see whatever we need to check in the past or moving forward. So it’s a key point for labs.


And then yeah, Like Marcelo said, it’s a matter of keep improving and keep getting better. Currently, we are working, developing a kit for targeted yeast propagation with invisible sentinel. So I think it’s going to be – Once done, it’s going to be really, really interesting too.


[00:48:05] ED: We have a 24 test that we do on our yeast, and that includes a two-week QA/QC after the yeast is packaged. We test for stability, for genetics. We run mock fermentations. And we’re really proud that when you pick up a brick of wild and yeast that it’s 100% pure and stable and we really stand behind that.


[00:48:27] TR: Excellent. I certainly didn’t mean that as a gotcha question, and you certainly all work for really well-established and respected yeast banks and suppliers. Unfortunately, our time here is pretty much up. I had a lot more to ask. And who knows? Maybe the first-second episode of the Brew Deck. And I know on the BrewDeck we’ll probably have you guys contact information, certainly representatives for your company if anyone has questions or is interested in more follow-up. But at the end of the day, thank you guys, all of you, so much for taking time out of your day and helping to make this a fun and really interesting and educational podcast. Thanks a lot, guys. And we’ll talk soon hopefully.


[00:49:13] PG: Thank you.


[00:49:14] ED: Thank you.


[00:49:13] MC: Thanks very much. Thank you.