Hop Creep Isn't a Myth: Science, Risk, and Real Solutions with Jessica Young

Hey everybody welcome back to the Scarmor and Labs podcast to show where we break down fermentation signs for brewers at every level I'm your host and fill in producer Mark Ruchinski and I'm Richard Praes CEO of a Scarmor and Labs and today we have a Very special guest. We're gonna be talking to Jessica Young from UC Davis Basically, this is our first episode with a guest. So I'm I'm I'm also hoping it goes well Give a little bit of a background about Jess. I've known Jess for a few years now kind of running through the the brewing science circuit But Jess earned her undergrad degree in cell and molecular biology before delving into brewing in Asheville, North Carolina. She joined bearded iris brewing in Nashville in 2017 Then advanced to cellar quality and sensory manager She did all the beer things Jessica has shared her expertise on the master brewers and brewing network podcasts And she has published a research in the master brewers technical quarterly and the journal of food microbiology and the journal of ASBC She's now currently wrapping up her PhD in food science with a focus on beer and brewing at UC Davis Jessica specializes in breaking down complex concepts into digestible bites and solving problems in the brewing industry and this episode is also coming out on International Day of Women and Girls in Science So what better to then to have one of the what I think is one of the rising stars in brewing science on the show Wow, thank you So welcome Jess. Thank you. You made me sound much better than I maybe am That's I think that's my job here. So yes. Yes. I'll keep trying that Perfect. So I I first I guess I first encountered you in some of your work. You were talking about you know how to harvest yeast You know out of tanks with mid fermentation dry hop and I think we can get into that a little bit later But your PhD is mostly focused on hop creep which is a topic we've we've kind of talked about a little bit on the show But we've avoided it because I knew this was going to come up at some point And I'm like we got to get an expert here because there's all sorts of crazy stuff going on under the hood with hops But just to start us off what is hop creep Well after the many years that I've been focusing on it I've come up with what I think is a pretty good definition I define hop creep as the unintended secondary fermentation that comes from adding hops on the cold side So if you dry hop you are getting a secondary fermentation and that is hop creep Okay, so unintended fermentation. Yes. Okay. That's a good way to put it Yes So can you just sort of break it down and obviously there's a lot of different layers to this but What does that mean for the brewer what problem does that cause? So there's a lot of different things that are happening And for a long time people kept defining it as diacetyl and That's a symptom. It's like getting your stuffy nose When you get the flu but the actual problem is the virus or the bug that you have and so hop creep is making this Extra fermentation happen and a lot of people started picking up on it just from the diacetyl And so that's one issue that can happen that's negative Usually Birds will allow that to get cleaned up and then it's kind of fine But what they're also letting happen is that fermentation that needs to happen. So Obviously with fermentation you have an increased amount of CO2 an increased amount of alcohol Which is an issue if you're labeling your cans at a certain level And then you will have a decreased residual sugar because it's eating up the sugar Which means that then you may have increased perceived bitterness And you are also now going to have an inbalanced beer that has higher carb, higher alcohol, decreased sugar and Probably doesn't taste as balanced as you were intending when you made that recipe So and then hopefully That's happening in the fermenter but sadly it can happen in package And when that happens that's when you have exploding cans and you have cans where you pop them that are buttered popcorn So that's where the big issue has come in is when it you accidentally don't let it happen in the tank And then it comes and happens in package so No good we don't want to exploding cans on the shelves Please no And like you said the dash was more of like a symptom but People just were noticing that this was was coming and they had no idea why and oh interesting. Okay cool. Yeah Why do you think it's become I mean no one talked about hop creep like six years ago five years ago. Why is it an issue now? Oh IPA craze maybe That's Maybe we're all start That Or maybe people were also focusing on quality more and they were you know just saying I don't want to put out a beer that isn't you know I'm not measuring the gravity every day and then they'll say oh wait the gravity still dropping and dropping and dropping and dropping Why is it dropping and so maybe it was a both a focus of quality and then also just throwing absurd amounts of hops into beers Okay, so hop hop concentration plays a role um Maybe I mean I One of my first experiments I tested if Essentially two or four pounds per barrel would create more hop creep and found that it did not statistically do it It's slightly more but You would think it would but it's not as much as you think the differences between two and four Not it's like since it's essentially negligible. What what I do remember So that's interesting so um Smoke but not fire basically What I do remember from some of the earlier work you were doing was you saw some pretty big differences in Hop creep potential between hop varieties. Can you talk about that? Yeah, so I would say If we want to say the most impactful thing for hop creep Product type is going to be number one um and so T90 is going to be The most hop creeper I'll say maybe that's a word. I'll say um invent right now uh It's the creepiest Form of hops the creepiest farm um, but it is the most used form But it so it creeps the most but it's actually the most consistent Which I think is something maybe viewers are looking for mostly is to find consistency in their hop creep So although it creeps the most it is actually really consistent And then you know you've got cryo and whole cone is the least but when we talk about the variety There's a lot of interesting stuff that happens there as well because I tested multiple crop years and multiple locations of hops And there was actually consistent they've ended up in the same grouping each time Which I think a lot of people say oh well this year I got more creep and this year I used to this one from Michigan and I got less creep but it's actually really anecdotal because When I tested it I did not see that I would say product type is the most impactful thing Anacdotes in the brewing industry Shocking and shocking I know so I mean I came in and I I was a brewer myself and I made the anecdotes myself in the brewery and um so my first experiment was to test those anecdotes Dry hopping more gives you more hop creep no, you know like things like that so Cool, so if I mean Can you call out any specific varieties that are like like really aggressive for hop creep or like Really neutral sure So cascade Historically is a high hop creeper the most creepy of hops there we go that is the creepiest one okay, okay cascade both years and both um I think I tested three different lots of it but both years were the creepiest both times Most hops actually fall right in the middle So if you're thinking of your favorite variety it's probably right there in the middle um night like a nice little bell curve And then you've got some that are like semi-low so Actually strata was um consistently you wanted to lower creepers all right the goat I know it's my favorite really yes, okay, I can't say favorite. I got to go simco What but strata's up there, right? Didn't didn't you work at Russian River? Come on Yes, so um, but I do love strata. I think it there's yeah There's a brewery that made me fall in love with it in Tucson and I've since then always loved it but Strata was the lowest creeper As well as some like German varieties which we would expect but no one is making Hullertal Blanc double IPAs so it's fine. I hope not Yes Okay That's interesting and so um after that work and I mean I Just sort of speaking from my own experience with seeing some of this research You kind of took that a step further and trying to figure out like where is hop creep coming from and that that's been like this big debate Forever, you know, you have People that'll argue and get data that says oh, it's actually you're getting microbes that come in and you know come into the beer and Make enzymes that uh, you know that causes the re fermentation or you get people that'll say oh no It's it's actually enzymes coming in from the hops that are breaking down, you know The dextrins in the in the in the beer or the wort and making it more fermentable So can you tell me if you've been able to figure that out once and for all and I think we'll probably get into why it gets even more complicated later on Yes, um, so I'm actually Weirdly a pretty good friends which are early at this point in my UC Davis time very thankful fully for that. And he was very amped when I disproved him. He was very excited about it. So Charlie was one of the people saying that microbes are likely the source of enzymes. And my latest work was the discovery of starch. And if you know about starch production, it in order to build and break down starch, it has to have alpha and beta amylase present as well as other ones. And so that proves that at least some of, well, it proves that some of the enzymes are coming from the hops themselves. There still could be microbes producing it, maybe excreting them, leaving it on the cone, and then that gets ground up and put in your beer. But we can at least confirm that the hops themselves are making it in the brack. And it's coming from there. So those enzymes would, yeah, it gets so complicated from there. But it is theorized that those break down dextrins in your beer. So that is one aspect of hop creep. I would say there's many more and probably some still to be figured out after I leave UC Davis. But the enzymes are from the hops. Some might come from microbes, but that's not proven. And we think that those enzymes are breaking down dextrins in your beer. Okay. And it gets, like you did, you mentioned this, it gets even more complicated because hops themselves are bringing starch into the equation. Is that, I know you measured it in the hops and is that something that actually carries over into the beer, like the starch in the hops can be soluble in the beer? Yes. So I, so I've tried to think of where to start here. So yeah, you've got about two to three percent of simple sugar just coming in from hops. So that's going to get fermented. So by weight hops are two to three percent sugars? Okay. Okay. And so there's that. Then there's plant secondary metabolites which release a glucose here and there, which are things like linole, right? That comes attached to a glucose that gets released and then you get linole and blah. So you have some sugars there that will get fermented. And then you have enzymes come in and then you have the starch. And so the starch can be really variable because it changes based on the time of day. And it's actually really different from the starch that's in barley. So barley is storage starch and it's packed super, super tightly in those granules. But because this is diurnal starch, it doesn't pack as tightly because it's not, there's not a purpose in that. It needs to break down entirely overnight. So the plant will build up exactly what it needs for its overnight hang out and then it'll eat it all up throughout the night. So it doesn't make sense for it to be tightly packed. So you have to gelatinize barley starch in order to get it to open up enough so that those enzymes can get in there and create, like, cut it up. But this is transitional starch. So it's already open. It's already available. And actually the beta amylase is stored directly on the starch, which is really cool because it's right where it needs to be. So my recent work is measuring that starch and I've been putting them in fermentation. It's not possible for me to really see if the starch is making it in there and if it's getting cut up, I can tell you the measured starch, the measured enzyme amount and the fermentation from hop creep. But you can't delineate where that extra fermentation is coming from yet. Someone smarter than me. Well, that's the thing with science. It never ends, right? It's just you just, you know, this keeps going deeper, right? It's fun. Yes, it's fun. It's a humbling pursuit. Humbling? Yes. Okay, so what's the best time of day if we want to reduce hop creep? What's the best time of day to harvest the hops? Well, it depends if you're on the starch side or the enzymes dried, right? Because if you need to break something down, you want more of that thing present. So what I've seen is as starch goes down, beta amylase jumps up. And when the starch is at its highest, the enzymes are at like minimal level. So it's kind of like, are you going to add 10,000 molecules of glucose in there? Or will you add 10,000 molecules of beta amylase? I'm just using random numbers. They're not exact. So I think it's, you're not going to find that sweet spot sadly. So yeah, the answer is you can't win. You don't have to go harvest your hops by the moonlight. Yes. Yeah. Well, it's not fun. I'll tell you that. So from experience. Yeah. What was that time course like? Did you have to camp out? So I went every four hours for 24 hours. Hell yeah. And I'm going to tell you it's really scary on a hot field at 3am. Yeah. Really terrifying. And then I did that for two different days. So not a lot of sleep in there. Everyone's got one of those experiments. Yeah. I'm like, why am I doing? Yeah. I had a couple of heroing ones, but I didn't have to go outside. So I think you win. It was like only slightly serial killerish at times. I think we have a pretty good understanding of what hop creep is and where it comes from thinking practically, like what can a brewer do? If they want to keep putting tons of hops or tons of aroma in their beer, how can they actually mitigate that risk? So I think I will say you need to learn to work with it in your own system is always my first advice. Because I say something doesn't mean that that's the way you should go. I am a fan of mid fermentation dry hopping. I think for several reasons. One, that primary and secondary fermentation are going to happen at the same time. And so for the most part, your hop creep lag is going to be super minimized. So you might have an extra three days at the end of your normal fermentation of an additional little bit of drop. So it's not you're not sitting there for two or three weeks after waiting for that fermentation to end. The other thing to think about is more of like a thermodynamics thing where reactions happen faster at warmer temperatures. You're going to ask those molecules to bump into each other more often. You're going to ask them to bump into each on a each other faster. And so you're asking for that that reaction to take place faster. So when you dry up cold and the yeast is already I'm sleepy. I want to go to bed like and then you're like oh here's more sugar. Come on, let's ferment. Let's take up the diastyl again. The yeast is done. The reaction takes a really long time. Like I don't even want to imagine the amount of time it takes to clean up the diastyl. People are using ALDC which is fine but you're really putting a band aid over something because you're probably not letting that actual fermentation happen. You have to let that fermentation happen. So number one is let hop creep happen and let it happen in the tank and do what it needs to do. I would say safe bet is three days of repeat gravity, repeat pressure in the tank and repeat pH and you're safe. But that's just how I ran my brood and I was very very safe when I didn't want things that go to go into can and be diastyl bombs. But my recommendation is mid-firm dry hopping. I think warmer temperatures letting it happen early get it out of the way. But a lot of people like cold dry hops which is fine but you need to let the reaction take place. Yeah. So you talked to them in mid-firm dry hopping and that's like that's something that comes up a lot with us because it is a common practice but what it means is that it's very difficult or nearly impossible to harvest and repitch the yeast. So you know people people don't like that. East is expensive. So I was wondering if you have any pointers for how someone could crop yeast and do a mid-firm dry hop. Yeah sure. I yeah this is in the NBA TQ if you're really interested super super detailed SOP in there about it. But essentially you can if you have both a blow-off arm and a CIP arm you can hook CO2 into your racking arm and then shoot it just I think I said like 12 psi I don't remember anymore but just shoot some CO2 directly into the racking arm and it'll just kind of flow out. It needs to be during like that really high krausen when it's like very fluffy at the top of the tank and usually if you're going to do that I recommend filling the tank pretty high actually so you have less to travel and usually you can just shoot it right out the top and have super great viability and super happy fluffy yeast. I forgot to say this but the other thing if you want to get through half-crate quickly is to add zinc on the cold side. Absolutely thank you also for that one. Zinc on the cold side. It is I swear by it it really gets get that yeast very happy and healthy and it is going to crank through hot crate. Yeah I will say I mean there's other options to get zinc but yeah cold side soluble great nutrients that have lots of zinc in them also great just kind of harder to control sometimes but yeah I would say that's number one is like a lot of these problems you talk about you know extended diacetyl it's like well there's probably an upstream yeast nutrition problem and then at this point you have to think about like what's going on with the yeast they're like they've already gone through fermentation they're like we're done we're going home where it's quitting time and then they're like hey there's more stuff to ferment you know that's not going to be the ideal scenario for the use. You're probably not going to get the best quality of work from the use. So if you feed it some nice nice treats going into its job It might be a little bit more willing to complete that fermentation. Absolutely. Absolutely. So yeah, healthy, East, happy, East, and then just shoot it out the top of the tank and it'll think it's on a roller coaster. Yeah, this is like, I mean, it's a cool method. It's like coming up with a way to do top cropping in a closed vessel. Basically, right? Exactly. Exactly. Yeah. It's like six flasks. We're going back. We had that little poster with like the amusement park of different like brewing things and like the like the world pool ride and like all these different things from the brewers. Remember? I do. And we have this poster up that I think we sent out to a bunch of breweries, but it's it's a little called six flasks. And it's just like this. This was like a COVID fever dream of mine where I like came up with this thing and like sent it to our designer. And like it's just like this, you know, diagram of a theme park, but it's all like fermentation related. So like there's the Tilta whirlpool and the fermentation tower of terror. And just like then there's like a bunch of tips on it. If anyone has one of those, let us know because those are pretty rare. Yeah. But that was a lot of fun. Very much a COVID fever dream of like being stuck working at home for like weeks on end. Creativity blast. So with all of these things considered, I think you've given actually some really, really good practical tips for like how brewers can manage hop creep and just overall general tips for IPAs. I think you're you know, your brewing experience really helps to kind of play into that as well. What's next for you? Oh, I hate this question. Now that my PhD is ending, I get it very often. Not totally sure. I've had a couple offers, but I don't know. I like solving problems. I don't want to be an academic. So I know that I miss being around stainless. I miss the stainless. You know, so trying to get back in the brewing industry somehow and probably still be very close to hops because I still love them after so many years working on them. So, yeah, you want to be near stainless and hops. Stainless and that sounds like a brewery probably. Yeah, yeah. Something around there. Hopefully very, very cool. Is there anything else you want our audience of yeast nerds to know anything they should check out? All hops have hop creep. That is the one thing I would like people to take away. Maybe all hops. All hops. Well, yeah, all of them that I've encountered. Okay. Has anyone come up with us, you know, a hop free product that does the same thing? Huge negative. Okay. I'm sorry to all the hop companies. I love you, but it's not hitting the mark. You still need the plant matter. And my humble opinion. I've not found one that gives the same effect in the beer. I think it affects the mouth feel usually for me. Even sometimes when cryo gets too much, it turns into like a gritty texture. So nothing is giving that. I think real hops are need to be the primary focus of the recipe. You can maybe toy with some of them in small quantities, but none of them have come anywhere close in my opinion. So we don't have the holy grail yet. Nope. Okay. We'll keep searching or just use real hops and let it happen. Because that's the best. I love that philosophy to it's like let's accept that this is a thing and work with it and you know set set up the process for success. Absolutely. Rather than trying to fight it with technology. I think that that is a good philosophy to have. That's the way I think it. People are always asked me when I get to the starch stuff. They say, well, what can we tell the farmers? And I'm like, it's not the farmers job is done. They made a good thing. They made this delicious hop for you. So it's your job now. You know, that's what Brewers are here for. Well, thank you so much, Jess. This was super informative. Really looking forward to learning more about the rest of your PhD. I'm sure there's still some stuff that hasn't been published. So I know I'll be following along and I hope everyone else does too. You want to take us out of here, Mark? Absolutely. Absolutely. I hope I did a good job. Our normal producer Nicole. I'm feeling with her, but she's at the pink boots conference right now. So again, thank you so much for being here. It's been great. Where are we going to be next, Richard? Where are we going to be next coming up? We have master burrs district Eastern Canada is meeting in Montreal on February 17th. We're going to be talking about yeast nutrition. Texas Brewers Guild. That's February 20th to 21st. Come on down. We'll have a booth. We're pouring some beers. Downey Spurs Conference in Frederickton, New Brunswick on March 5th and 6th. Also talking about yeast nutrition. Headed across the pond of beer acts in Liverpool, UK, March 18th and 19th. I'll be with the Lallaman team talking about some of our work with yeast strain development. Then heading over to the Minnesota Brewers Guild April 9th and 10th and then wrapping up our little spring tour at the craft brewer's conference in Philly April 20th to 22nd. We've got a pre-meeting workshop. Check our booth. We're going to have a little evening event and then also talking about yeast nutrition alongside Dr. Glenn Fox. So just as a advisor. That's funny. Yes. Thank you guys so much. Also having me. Oh, it was so great. It was so great. Thanks again. And again, everyone listening, make sure to visit Descarp and Labs.com to learn more about our yeast in science. Send your fermentation questions to help it. Descarp and Labs.com for future episodes. And subscribe to Descarp and Labs podcast. We're review. Listen. Cheers everybody.