UCSF Brewers Guild

Spectrum

Members of the UCSF Brewers Guild (Yug Varma, Kenton Hokanson, Ryan Dalton, Scott Hansen, and Rober Schiemann) discuss the science of beer making.

Transcript

Speaker 1: Spectrum's next.

Speaker 2: [inaudible].

Speaker 3: Welcome [00:00:30] to spectrum the science and technology show on k a l x Berkeley, a biweekly 30 minute program bringing you interviews featuring bay area scientists and technologists.

Speaker 4: Good afternoon. I'm Rick Karnofsky, the host of today's show. Today we're talking about the science of Beer with UCF brewers guild members. You've Varma, Kenton, Hawkinson, Ryan Dalton, Scott Hansen, and Robert Shimon. Can you guys please introduce yourselves and say what your research focuses on?

Speaker 5: [00:01:00] Hi, I'm Yogi. I am a post doc and I studied the human microbiome. We study bacteria associated with the human body.

Speaker 6: I'm Kenton. I'm a Grad student and I said he synapses and the regulations. Mostly I am concerned with homeostasis and the idea is if you perturb one half of us in attic pair, then the other half somehow recognizes this and quickly adapts itself to maintain normal neuronal function.

Speaker 1: I'm Ryan, I'm a graduate student in neuroscience [00:01:30] and I study the olfactory system. My name is Scott Hansen. I'm a graduate student and the questions I've been interested in are how cells interpret signals from their environment. Being a biochemist, I tried to understand how the proteins at the cellular level are being rearranged and forming different complexes to produce shape changes. My name is Robert Shimon. I'm a first year graduate student. I'm setting bioinformatics and uh, I got into brewing beer as an undergrad. When that [00:02:00] my hobbies, I kind of start doing something and I get completely obsessed with it. So I, at first I was, uh, didn't drink beer at all or didn't drink any alcohol and then, uh, had my first taste of beer and then decided within a couple of months that I'd start brewing and haven't looked back ever since. Cool.

Speaker 5: Scott, can you please explain what the ucs F brewers guild is?

Speaker 1: The UCSI brewers guild was founded by myself and Michael Schulty and Colin does more about three years ago. So we decided to just hang [00:02:30] out every month and just talk about the beer that we were making. Shortly after that, I joined forces with some people at linkedin laboratories and a the Soma San Francisco and they provided a venue for us to start having biannual beer brewing festivals.

Speaker 5: Youth, how do we get beer? So beer is a holy confluence of hops, east malted barley or malted grains [00:03:00] and water. In fact, there is an ancient beer law [inaudible] which is the earliest consumer protection law and that says that beer must be only malted barley and hops and water. At that time. They of course did not know that east made beer. That discovery was made by Pester in the late 18 hundreds but essentially that's what beer is. Can you explain to us Robert? So the majority of grains used in brewering are malted grains. [00:03:30] And so what that means is basically after the grain has been harvested, it's taken, it's soaked in water, are allowed to absorb a certain amount of water and then allowed to germinate. And then once it reaches a certain stage of germination, it's roasted too to help germination and prevent the the seed from converting all of the starches into simple sugars.

Speaker 5: But it's allowed to germinate long enough such that it produces the enzymes next necessary for the conversion of the starches into the sugars or the other reasons to get out these simple sugars. Some of these simple sugars are available [00:04:00] to the yeast right at the end. The chief reason why some of these start just have to be converted to sugar is because the next step is to roast them. Right? And the roasting process stops the germination, but it also causes a lot of the mired reactions to occur. The different flavors that you get from Malter because of two reactions. One is caramelization, which is just a sugar caramelizing, which gives you the Tophi sort of, you know, sweet caramel flavors. The other is the mired reaction, which will give you anything from bready to bread [00:04:30] CROs to nutty Biscotti chocolaty coffee. You know, that's the progression of flavors depending on how long euros and how dark the roast is.

Speaker 5: And so for the Meyer reactions, of course you need amino acids or some nitrogen source and then you need the simple sugar because if you have the complex starch, all it'll do is burn. You're listening to the spectrum on Calex I'm talking to with the UCS have brewers guild. Now, is it fair to say that a lot of the difference in flavor that you get is from this malting process and this roasting process or do you get [00:05:00] differences based on where the multis grown or that kind of barley used for the malt? The variety of multi is important. The where it was grown I think less so. There's two row barley and there's six rolled barley. So two row barley has a lot more enzymes but very little sugar and six roll barleys the opposite. So you want some Touro barley to provide all the enzymes during mashing to break down the starches.

Speaker 5: But you need some starches around six row malt is added to just get the heft [00:05:30] of the sugar in and are non barley and grains molted both that took, some are rice is not because rice is just a ton of simple fermentable sugars. Wheat is and Rye. Yes it is oatmeal. No. Okay. Um, you consider that's a non barley. That's a good point. Um, well you can roast oatmeal at home. I don't know if the oats, you get a roasted [inaudible] you get, [00:06:00] it would not be roasted, but people do toast it in their oven. Oh yeah. And that again, there's a little in my yard magic and gives you some roasted oatmeal flavors. So Kenton, the next process is to boil the granite, is that right?

Speaker 6: Grain carries it inside of, it kind of starts as like a stored energy source. And what we do as brewers is buy grain that has all this starch. We crush it up and then soak it in water that activates a bunch of enzymes, [00:06:30] which are just little machines that chop up these starches into sugars. A ton of thought and work goes into just turning those starches into sugar using nothing but water at the appropriate temperatures and then flushing it out and we try to flush out as much of the sugar as possible. And then we've made sugary water that also has other compounds from the barley that gives a different characteristics. And then we just will, we boil it and he did that to sterilize it. And also it gives you an opportunity to add things that flavor. It's southern most common [00:07:00] of those obviously as hops.

Speaker 6: And when you boil hops, they UI summarize an acid inside of them that turns the the sugar water, which we call wart more bitter. And that's also a time when you can add other things. Coffee, beans, fruit. And what's the spice that we often use? Corn Polo. Oh yeah. We used to the peppers a yeah. Of Coriander. Um, it gives you a chance to dump in anything you like that will influence how the, the final product tastes or if you dump it in right at the very end how it smells. [00:07:30] And so once you've boiled it for as long as you want to, you cool it as quickly as possible trying to keep it from being contaminated by any of the bugs that float around in the air. And then you dump in yeast, which love the sugar that you've put into the water. And so they will just go crazy for a few weeks fermenting when they ferment, they produce CO2 and alcohol and that turns the wart into a beer.

Speaker 5: And Ryan does the boiling process change the malt in other ways.

Speaker 7: You drive [00:08:00] where it called my yard reactions, which are reactions between diverse sugar molecules and the diverse short proteins and amino acids that occur in the beer. These reactions are essentially a linking of these two molecules and because you, you're creating a very heterogeneous set of compounds, you have a flavor that is very complex and it's very hard to replicate without actually boiling this set of ingredients together.

Speaker 2: [inaudible]

Speaker 8: [00:08:30] you're listening to spectrum on Calex Berkeley memories at the ucs after his guild are discussing the chemical conversions at the solutions of multi barley and hops and their analysis of homebrewing data [inaudible]

Speaker 1: so Robert, let's talk about hops. Actually, one trend that I kind [00:09:00] of think is pretty cool and interesting on the technology side of things is that some breweries are using now it's called a super critical hop extracts packet tube full of hops. You pressurize it with CO2 on one end and all of the hot oils are kind of forced out and you're left with all the vegetable matter in the tube and you have all kinds of those. Nice, wonderful, rich oils left out of it. These breweries have taken to using these superhero hop extracts to kind of reduce their losses and beer and also kind of just increase the amount of hot oils you can get into beer and how do we get new hot varieties [00:09:30] and some understanding of how new for hot varieties arise is that they had this group up at Oregon State University. They breed new hops, get different hop varieties, try brewing beers with these new hop varieties, see if they taste good. If they taste good, they'll distribute them to breweries for them to experiment with. If the breweries like them, then they'll become kind of mainstays and you hops propagate by a rhizome.

Speaker 5: Yeah, it propagates by Rhizome, which is actually a route modification under the ground and so it's very easy to swap rhizomes with someone who's growing hops and grow your [00:10:00] own because rhizomes are super hardy. They grow in binds, which are essentially creepers and their stem has this super velcro material, which is great to play around with. You just stick it on anything that has a fiber and it'll just latch on it. It's very, very tough. And anyone who's grown this will attest to it. They're really hard to get rid of once you've had them in for a year or so in your garden. Super Tunnel. Yeah. And they grow super tall and they grow super fast. Uh, you're a newly growing hop. Bine will [00:10:30] grow up to, I've heard a foot a day, which is kind of boggling, but I, I have seen it grow several inches a day.

Speaker 5: Wow. Well, my hops will probably start a blooming in July or August and they're usually ripened by September or October depending on the season. Initially they're these green almost line green or, or darker green upside down sort of papery chandelier's. Uh, they look very [00:11:00] delicate and beautiful and when they're wet, they're kind of soft to the touch. But when they dry out, they get slightly more Brown and get papery and they have a kind of pollen that you can, that sort of rubs on your fingers. And when they get papery and dry, that's when the oils and the mature, and that's when you're supposed to harvest them. Even at that stage, they're usually a little wet, so you need to dry them. Air Drying is preferred over a oven drying over [00:11:30] the lowest possible temperature setting because obviously oven drying will get a lot more of the volatiles out of the house.

Speaker 5: And what does this air drying process do? It just takes the water out. The air drying, partly matures the oils and it removes the grassy flavor because if you ever use wet hops in your beer, it'll taste like a mouthful of grass. The alpha acid that is often talked about by homebrewers is chiefly Humu loan, which is a fluoro all [00:12:00] derivative. And that I summarizes when you boil it into ISO alpha acids. Now, Humu alone on its own is not very soluble, but when you boil it, it gets more soluble. So you actually extract it. It also gets more bitter. The bitterness of course is a little, it gives a little bit of a stringency, which is bracing. But uh, more importantly, uh, hops is the chief antibacterial compound in beer. It Ma, it helps massively [00:12:30] to prevent spoilage. Hops are actually a soporific, right? They are. They're estrogenic. And, um, in fact, one of the, um, other things that I'm going to use them for is make hop pillows, just stuffed them into pillows and uh, apparently they help you sleep at night. Yeah.

Speaker 7: This is spectrum. We're talking with the UCF brewers guild. Ryan, does water chemistry matter? The historical example that everyone always cites is the beers that come out of Burton on Trent versus the beers that come out of Dublin. The beer that comes out of Dublin is black and you know, you wonder [00:13:00] why it's black. It's great. You know, perhaps is not black because the, the people of Ireland, uh, enjoy a dark beer. It's, it's black because the water chemistry necessitates that. And the reason that is is because these enzymes that are converting starches to sugars during your mash depend on Ph and barley that it has been roasted for different amounts of time, have different effects on the acidity of your mash water. In Dublin where the water is quite basic, it needs to be acidified by a dark malt, which has a strong [00:13:30] power to acidify water to bring it into the range where these enzymes are active. Whereas if you have water that is already without adjustment at that Ph range, you do not need to to use dark malts and you can create a a lighter beer. I incidentally, the tap water in San Francisco is really good for a pretty diverse range of styles. And why is there water so good?

Speaker 6: That's very low on minerals. So it gives you a lot of flexibility to add the minerals you want. It comes a little basic to begin with. So we often [00:14:00] add minerals to our mash to lower the Ph, but it'll, it'll turn out most things we, yeah, there like Florida where my sister lives, the water is cell-free and I don't think you could even brew with it. You know, one of the parameters that will affect how your, your beer tastes in the end is this sulfur to chloride ratio. And I don't think you could add enough chloride there. It's disgusting. So you know, in San Francisco we are,

Speaker 5: this is actually funny because usually most a [00:14:30] beer book say, Oh, you know, you should worry about the chloride content of your water because water is chlorinated in most municipal water supplies and [inaudible].

Speaker 7: So do you use regular tap water then or do you filter it in some way reverse osmosis or buy distilled water?

Speaker 6: A lot of people will cut their water with distilled water or reverse osmosis water to reduce the mineral content. Not Necessary, at least in San Francisco or anyone who gets their water from Hetch Hetchy, which is sort of a natural filter. So we don't, we don't [00:15:00] cut our water with anything. We add minerals to it for almost every brew [inaudible].

Speaker 5: So I, I started d chlorinating my water with Campton tablets. Do you guys do the same? Do you think that's necessary? I started using a, a sorbic acid, just vitamin C, which basically has the same thing as a Campton tablets. But honestly, I haven't noticed any flavor differences in my beard since I've started.

Speaker 6: The San Francisco water report has the chloride content and it's not extraordinarily high. Yeah. So it's probably not a bad thing to do, but it's not necessary. [00:15:30] Yeah.

Speaker 5: Yeah. In fact, one of the best ways of removing clothing from water register boil it boil for 15 minutes and you're pretty much getting rid of all the chlorine. So do you think that in the process of boiling all of the sugar and the wart that's equivalent to pre boiling water? I would say so. Uh, especially by the time it hits, I mean, or rather the heat, the yeast hits the work. Um, you're probably clear if a lot of, or [00:16:00] all the clothing that you should basically be worrying about would have just dissipated. Another way of getting rid of clothing is just, just pour water into a pot and just leave it out for hours and hours. So boiling is much more fast and efficient. Is it evaporating? It is. It's available tile. Um, and you know, it just, uh, it ds as the water is, that's what it does.

Speaker 5: It just drives all the gasses dissolved gases from the water. The only problem is that that doesn't work for chloramines. So yeah, you can convert the chloramines [00:16:30] into chlorine by adding Campton tablets or a little bit of Campton tablet or a little bit of a citric acid or sorbic acid and then that'll convert into chlorine. And then either through boiling or letting it sit out, the chlorine will evaporate. Yeah. But I mean, I frankly love San Francisco water out of the tap is delicious to drink it. It's really one of the tastiest, sort of an unprocessed waters that I haven't drunk.

Speaker 4: What kind of minerals do you add and why?

Speaker 6: So we mostly add calcium [00:17:00] chloride and calcium sulfate. We, we basically drive the Ph as low as we can until our mineral additions get excessive. And we just feel like we're making it hard and stupid.

Speaker 2: [inaudible]

Speaker 4: you are listening to spectrum on k a l x Berkeley. We're talking about the science involved in beer making with members of the [00:17:30] UC Sir Gurus Guild. Kenton. If a person were to just start homebrewing, what do you think is the most important thing that they pay attention to?

Speaker 6: I think temperature that is both really important and also one of the things that you get classically terrible advice about. Get a good thermometer. [00:18:00] If you're going to invest in one thing that doesn't come into standard brew kit,

Speaker 5: you should consider what the temperature is in your house. You should have thermometers in different places in your house. Figure out what temperature is. If it's 90 degrees in the middle of the summer, you're not bro-ing okay. Unless you have a refrigerator. So, so just the temperature is think about what type of beer you want to make and then you know, brew with the seasons. I think that's the best way to do it.

Speaker 6: Ryan, what kind of data [00:18:30] do you record when you're brewing?

Speaker 7: We have a really good time brewing. You hear people say all the time that brewing is both art and science, right? In our brewing process and in our brewing theory, the art is in the exploration, but the science is sort of in making sure that we can get back to where we've been

Speaker 6: for people. Like I think all of us in the room who are like probably unhealthily obsessed with data and getting it consistent and [00:19:00] being in control. Maybe the biggest obstacle to brewing and getting satisfaction from it was the terrible information that's available on the Internet. When you have a question that you want to answer to and you've just go out into the world looking for it, then some of the information is old and some of it is just like willfully wrong where someone has made the decision and like posted authoritatively about it and they're just wrong.

Speaker 7: Yeah, I mean if you Google something and you get your answer from Yahoo Answers, then it's wrong. Right? [00:19:30] But that's basically what you're dealing with when you, when you Google something about beer recipes that no one followed up on, uh, ideas that people have a misinformation pass from one person to another with complete, uh, authoritative tone.

Speaker 6: Yeah. So we started pulling together some things. I mean a lot of brewing is has been studied. I mean the breweries know everything and then we, homebrewers are sort of trying to like figure certain things out what we, on what parameters predict deficiency and everything. And so we started pulling together all the formulas, [00:20:00] everything into one place. So we keep track when we brew, we record things like our gravity's, which is the a measure the density of the water, which is a measure of how much is dissolved in the water. And we mostly worry about that being sugar. We feed that in a largely sugar depending on the way we mashed. Uh, so we record our gravity's and we record the lengths the durations are Boyle and things like that. And then we plug it all into what's been an excel sheet, [00:20:30] just a huge excel sheet that we call the beer gulay tricks.

Speaker 6: And it basically builds predictions for us. Like we plug in our brewing plan and it will tell us things like the color and the bitterness, the volume that we should get out of it, how strong it should be in the end, how much it should cost to brew the diastolic power. Right. That the same or different as, as you were saying, different grains have a different amount of enzymes but that's sort of known in a rough way. And so it'll tell [00:21:00] you whether you have sufficient grain that will, you know, power you through the mashing step, things like that. And so we put it all in one place, which is online as well. It will be soon to be real metrics. And so you mentioned that you calculate the costs of brewing beer.

Speaker 1: Is that mainly just you geeking out or do you, is this really a decision point

Speaker 6: whether you brew a beer or not amount? It's not a decision. So we basically want to triumph [inaudible] [00:21:30] the turning point, right? The main thing we look at is our efficiency. And so then we like have a beer that we produced that we love and then we just want to try to make it better. And one thing we can use is like if we're more efficient than it costs less to brew the beer. And that's exciting, but we would never buy less green. Let's save money on it.

Speaker 1: So for the wine making industry, they [inaudible] digital refractometers as gravity changes the refractive index of the liquid with which the gravity is changing also changes. And so when you, as the refractive index changes, if you [00:22:00] place this on the surface of a prism, the critical angle of light passing through this prism also changes. And so you can basically place a liquid sample on a prism ShineLight through the prism. And then from that you can kind of backward compute what the gravity of the liquid sitting on the prism is. And so what I'm hoping trying to do once I get a little bit of free time after I'm done with rotations in classes, my first year is to build, is to build a floating sensor that'll sit in my beer, give me real time temperature and gravity measurements with this little prison system. So [00:22:30] if any of you guys have any experience building, stuff like that, I'd love some help this summer. Scott and anyone else, what kind of advice do you have for aspiring homebrewers? One thing I often see with homebrewers is that they're so attached to their beers. The first batch of beer I made,

Speaker 5: I dunno if I want to like give it out. Holding onto that beer is pointless. The only way that you're going to get good at brewing beer is taking chances and just and just going for it. So the process is [00:23:00] just extremely robust. It's very difficult to make a bad beer so you can invest at any level you like. We like to, to really geek out and, and understand it. We were obsessed with controlling it, but you don't need to do that to make beer. If you can cook, you can make beer. Homebrewers are the most genial, open, convivial fellows I have ever met. They don't hoard recipes. Home brewers in general are some of the best people to hang out with, especially when we're brewing cause we're probably [00:23:30] at our happiest or close to. It usually consists of consuming homebrewers as well. So if you, oh, I think that's a rule. I think that was written down somewhere. So if you're not doing that, you're breaking some pretty harsh rules.

Speaker 1: Well guys, thanks for joining us. Thank you. Our pleasure. Thanks.

Speaker 3: And now for some science news headlines, here's Brad swift and Lisa cabbage.

Speaker 9: [00:24:00] The Economist reports that Dr. David Kaplan and biomedical researcher at Tufts University who has studied silk for 22 years and devised ways to use silk and biomedical applications, has developed a new way to pack medicines into tiny silk pockets that make the medicines almost indifferent to heat boiling silkworm cocoons in sodium carbonate. Caplin separates out of protein named fibrillin. He mixes the fibro in was salt. Then mixes that solution with the medicines [00:24:30] to be preserved and spreads the results out as a film before freeze drying them. The process immobilizes the medicines molecules preventing them from unfolding and thus losing their potency. Dr Kaplan and his team demonstrated the effectiveness of their new technique by trying it out on the measles, mumps, and rubella vaccine, as well as the antibiotics, tetracycline, and penicillin. The medicines when stored using this process retained 85% potency after six months at 45 degrees Celsius. The next step is to begin human testing [00:25:00] of the silk film medicines. If successful, this process will have enormous benefits for the global distribution of medicines. Currently, most medicines, including vaccines, require refrigeration to retain potency. The World Health Organization estimates that half of all vaccines produced are destroyed because refrigeration is lost at some point during distribution.

Speaker 10: Science magazine reports that an international team of plant biologists working with the u s da have found that mitigating [00:25:30] climate change through carbon sequestration actually pumps more carbon into the atmosphere. Increased carbon dioxide stimulates the growth of our boosts dealer. My Corozal fun guy, a mF , a type of fungus that is often found in the roots of most land plants. Experiments were conducted in greenhouses as well as fields of wild oats, wheat and soybeans. Lay Chang post-doctorate fellow in plant science at Penn state said elevated levels of carbon dioxide increased [00:26:00] both the size of AMF colonies and decomposition. AMF colonies are found in the roots of 80% of land plant species and play a critical role in Earth's carbon cycle. The fungus receives and stores carbon. A byproduct of the plant's photosynthesis from its host plant in its long vein likes structures as the carbon transitions to the soil. The AMF triggers additional decomposition of organic carbon near the plant's root systems. This decomposition releases more [00:26:30] carbon dioxide back into the air, which means that terrestrial ecosystems may have limited capacity to haul climate change by cleaning up excessive greenhouse gases. The big fear is that this will turn the soil into a carbon source

Speaker 9: rather than a carbon sink. A regular feature of spectrum is a calendar of some of the science and technology related events happening in the bay area. Over the next two weeks. Here's Brad swift and Lisa cabbage. Scott Stevens, [00:27:00] associate professor of fire sciences at the UC Berkeley College of natural resources and a past guest on spectrum will present a lecture entitled fire and Ecosystem Resiliency in California forests Thursday, September 13th from noon until 1:00 PM room one 32 in Mulford Hall on the UC Berkeley campus. The California coastal cleanup day is Saturday, September 15th from eight 30 to noon. Historically, this is the largest statewide volunteer event. The cities [00:27:30] of Berkeley and Oakland are organizing shoreline cleanups. The East Bay regional parks district is also organizing shoreline cleanups along East Bay waterways. Pick up every bit of human made debris you can find and record what you remove. Data collection is important. Your data goes into ocean conservancy's international database.

Speaker 9: Used to identify the sources of debris and help devise solutions to the marine debris problem. To get involved and get more details, contact Kevin Fox at the East Bay regional [00:28:00] parks district. Patty Donald at the city of Berkeley and Brin Samuel at the city of Oakland or a search online for California Coastal Cleanup Day on September 16th from 11 to 12:00 PM the UC botanical gardens at 200 centennial drive in Berkeley will present a lecture, small space orchards growing fruit trees in small gardens, Claire and author of California fruit and vegetable gardening. We'll show you two simple techniques for growing [00:28:30] a small orchard in a typical bay area home garden. You'll learn the best fruit varieties, space saving techniques and plant and care for container grown fruit trees and much more copies of Clare's book will also be available for purchase. You must register in advance

Speaker 2: [inaudible].

Speaker 3: The music you [00:29:00] heard during say show was Palestine and David from his album book and Acoustic

Speaker 2: [inaudible].

Speaker 3: It is released under a creative Commons license version 3.0 spectrum was recorded and edited by me, Rick Karnofsky and by Brad Swift. Thank you for listening to spectrum. You're happy to hear from listeners. If you have comments about the show, please send them to us via email. Our email address is spectrum [00:29:30] dot [e-mail] join us in two weeks at this same time.

Speaker 2: [inaudible]

Speaker 3: [inaudible].

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