tracey peake:  Welcome to NC State's Audio Abstract. I'm your host, Tracey Peake. Today we're going to talk beer with John Shepard, director of the NC State Brewery. Dr. Shepard is a professor of bio-processing science here at NC State. Welcome, John.

john shepard: Thank you, Tracey.

tracey peake: Beer has been around a really long time. What can we hope to learn now by studying beer?

john shepard: Good question. Beer is, as you know, one of the oldest products in our history of our technological world. It goes back many hundreds of years, and as it turns out, beer process, the brewing process, was one of the first, if not the first process that was worked on simultaneously by engineers and scientists. This was back several hundred years ago in Europe when, especially the Germans, were looking at beer as a very valuable export commodity, and they needed to improve the quality of the beer, especially during the hot summer months, so they engaged both scientists and engineers to try and improve on the brewing process, so it is a very good example of how science and engineering go together in order to help improve technology and product quality so that everybody enjoys better beer.

tracey peake:Beer has essentially, what, four main ingredients? And from those four main ingredients, we can make myriad varieties of beer. Could you explain a little bit about the most basic way that we can make different varieties of beer? Is it just by alternating these processes or amounts or ingredients?

john shepard:Yeah. There are two different ways of adjusting the recipes in order to make different style of beer. One way is to use different ingredients, although there's four main ingredients, you look at malted barley, there's over a dozen kinds of different malted barley that can be used, and so each variety of malted barley has a somewhat different effect on the flavor of the final beer, so that's one of the ingredients that can be varied, so the variety of barley plus the amount of the barley will affect the recipe. Second, most important flavoring ingredient, are the hops, and again, there are dozens of different hop varieties, and depending upon the variety of hops and the quantity of hops used, will affect not only the bitterness of the beer but also the flavor profile and the aroma, so those are the two main flavoring ingredients, although water and yeast do have an effect, especially with lager beers which tend to have less hops and less rich in barley flavor. Yeast can have a major impact, especially with those lager style beers.

tracey peake: When we're talking about yeast, what role does yeast play in the brewing process? 
	
john shepard: Yeast is critical for brewing because yeast is the living organism that converts the sugars from the malted barley into ethanol and carbon dioxide. However the yeast also produces some byproducts of the fermentation, and these byproducts do affect flavor and aroma in the beer, some yeast more than others. The temperature of fermentation, for example, and the variety of yeast will affect these other flavor compounds, but largely the yeast is there to make the ethanol. That's the main purpose of fermentation.

Tracey peake: Which is what makes the beer beer. Yeast is something that you’ve been looking at particularly in the last few years with some species of exotic yeast. Now in your work you have worked with some yeast that come from some unexpected places. Tell me a little bit about those.

john shepard: There are many, many different species of yeast out there in the environment, and most wild type yeast species are really not desirable in the brewing environment, and the reason for that is that even though they may be able to do well in the fermentor, from the point of view of fermenting the sugars, they don't have good yields of ethanol and they often don't make nice flavor compounds. They make what are called off flavors, and these off flavors essentially spoil the beer. The challenge we had, was to come up with a species or a strain from a particular species that gave us the good fermentation qualities of traditional yeast and not the bad things associated with typical wild yeast. Different yeast species inhabit different environmental niches, so some yeast species are easy to find in the air, for example. They'll just settle on your plate of sugar or something because they just fall out of the air. They're there all the time. Other yeast species are found, for example, on the bark of trees. Other yeast species can be found in the grasses. Other yeast species could be found in insects. Other yeast species in higher animals like mammals, even. So every yeast species depending upon how ubiquitous they are, typically they're looking for in different environmental niches. As it turns out, the yeast species that we've recently commercialized came from flying insects, one from a wasp, one from a bee. Not to say that's the only place this species could be found, but it tends to be one of the locations where it's most easily isolated from.
	
tracey peake:	Let's talk a little bit more about these yeasts that you got off of insects. You got one from a wasp. What does that yeast do specifically if you use it in brewing?

john shepard: This was as much a surprise to me, honestly, as anyone, that a yeast that lives inside the gut of a wasp would be able to ferment maltose. Maltose is the primary sugar that is released during the brewing process from malted barley, so it is a sugar that is not commonly found in nature because as I say, it is a product of the brewing process, and is not just usually free in nature, however, this yeast from the gut of the wasp was able to efficiently ferment maltose. The second surprise was that it gave quite good yields of ethanol because one of the issues with wild yeast usually is that they get inhibited by ethanol, so even though they make it, it is a self-inhibitory compound that shuts down their metabolism once the ethanol gets to relatively low concentration, usually one or two percent will stop the yeast from fermenting. This particular yeast was able to tolerate high concentrations of ethanol, in fact up to 10% ethanol, and again how that happened in the gut of the wasp, I don't know. Maybe the wasp is full of ethanol at some point.

tracey peake:	That would be unique.

john shepard: Yeah. That was a surprise, that it had this ethanol tolerance, and the third surprise to me was that not only was it able to make ethanol, but it was able to make lactic acid, which is quite rare in yeast. Almost no yeast makes lactic acid. Lactic acid is commonly made by bacteria of the genus lactobacillus. They're responsible for making yogurt and acidified dairy products, but it's very unusual to have lactic acid produced by yeast, and this yeast was able to produce rather large quantities of lactic acid, resulting in actually sour beer, which is a growing style. It's becoming more and more popular, and so that's really why I decided to pursue the eventual commercialization of this yeast because of its unique characteristics.

tracey peake: So the usual yeast that we have domesticated over the years do not produce lactic acid. This is a feature that is unique to sour beer making, and is that what makes the beer sour, the lactic acid?

john shepard: In the traditional sour beer process, it is not the yeast that produces the acid that makes the beer sour. It is bacteria. As a result of that, the traditional method is very long and very tricky because you have a mixed culture of yeast and bacteria making the sour beer, and it can often take one to two years to make sour beer, and at the end of it, it may or may not be drinkable, so-

tracey peake:	It can be a waste of time.

john shepard: Right, and so it's quite a difficult style of beer to make using traditional methods, so the fact that your yeast is able to do this as a monoculture, that is without any bacteria, is a big advantage, and the fact that it only takes three weeks versus one to two years is also a very advantageous situation.

tracey peake: You also got a strain of yeast off a honey bee. Is that correct?

john shepard:	It's the same species of yeast that we got from the wasp, but it was a bumble bee.

tracey peake:	A bumble bee.

john shepard:	Yes. A bumble bee.

tracey peake:	It's the same species of yeast that you found in the gut of the wasp, but it's on a bumble bee.

john shepard:	In the gut of the bumble bee.

tracey peake:	In the gut of the bumble bee.

john shepard:	Yeah.

tracey peake:	Okay. With the strain of yeast that you're using that came from the bumble bee gut, would it also make sour beer?

john shepard:	Yes, it did.
	
john shepard:	Depending upon the fermentation conditions, I'm able to adjust the level of acidity, and I can actually make non-sour beer with either yeast as well.

tracey peake: That's pretty good. Do you have any plans to look at the guts of other flying insects to see if you can find some other strains?

john shepard:	Well, right now we have multiple strains from a variety of flying insects. We have a total of seven strains that I'm working with, and two of them I say are commercialized, and five of them are still at the development level, so we are working on new ones.
	
tracey peake:	Let's move on to the craft brewery industry in North Carolina. What are your thoughts on our local industry? We're obviously not the powerhouses on the coast yet, but how do you see us coming along?

john shepard: It looks to be a healthy industry here. We do have, especially compared to other states in the southeast, we do have a rapid growth in the number of craft breweries here over the last 10 years, and it still is climbing quite rapidly. I do see some warnings on the horizon. I think the market will become saturated within the next few years. There's only so many outlets for products. There's only so many consumers out there that are interested in craft beer, so it is growing still. The total consumption of craft beer and the consumption of standard industrial beer is going down every year, so there is a larger and larger market share, and I see North Carolina as being one of the more healthy environments for the craft industry. That being said, and I'm not making a political statement, but the taxation system here is not the best for the craft industry. We have one of the higher taxes from the state, however, I don't see many craft brewers closing right now, so that's a good sign. I think most of them have been able to carve out a market niche for themselves. Perhaps they're not going to get as big as they would've if they had started 10 years ago. I think the market is more crowded now, and maybe they're going to have to settle with a slightly smaller business than they might have if they had gotten in a bit earlier.

tracey peake:	Are there any beer trends on the horizon that you think are interesting or that you would like to see?

john shepard:  Well, I'm a traditionalist from the perspective that I think it's a major challenge to make beer in the traditional way consistently with high quality, and I've been somewhat dismayed by the craft industry where in the past, there's been a tendency to have the beer of the week, that there always had to be something new, always had to be some kind of new taste experience, rather than trying to perfect what their main flagship beer is, and trying to produce it with consistent quality. There was a tendency to always come up with a new flavor of the week, and I think customers ultimately don't want to have that forever. Ultimately, customers want to have consistent, high quality from a brewery of their choice that they're going to go back to time and again, and so I kind of see a return to more standard traditional styles of beer, especially European lager beers. I think focusing on quality and traditional styles to me is the way to go for a craft brewer that wants to stay in business on the long-haul. Some are doing that and some still are trying to experiment with new flavor profiles that maybe attract customers in the short term, but I think in the long term, it's not necessarily the best business strategy, so that's my take on where the craft industry has been and is going, and I think there will be a shakedown there within the next five years or so, and those that have consistent quality and have developed a really strong customer base will survive, and the other ones that are more experimental may find it harder.

tracey peake:	What is your favorite type of beer?

john shepard:	Well, I don't really have one favorite type of beer. I must say I'm just overall a beer lover.I think that's one of the big appeals to beer is that there are so many variety of styles available now, especially, that it depends on your mood and your tastes. What attracts me to a beer is balance and harmony in taste, and that means that just like a fine wine, you have different flavors that in one way compete with each other, but in another way, they harmonize together so that you don't have this war on your tongue. It's a subtle, sophisticated flavor, aroma experience that I value in a well-made beer.

tracey peake: Is there anything else that you would like to leave us with thought-wise on beer?

john shepard: Well, I think it's a really fascinating time to be involved in brewing in the US right now because it is so dynamic a situation. There's so many people interested in it, and I must say, when I first started in brewing something 25 years ago, nobody was interested in interviewing me. It wasn't really something you were supposed to talk about even, so now the fact that there is such public acceptance and it is such an important fabric to our society both culturally and economically I think is just great.

tracey peake:	It's kind of nice to think of this as maybe an American beer renaissance where we're getting a little better.

john shepard:	Exactly, and there's a lot of interest in Europe in the American brewing industry. I think they're really wanting to learn a lot of things from the craft brewing experience here, and I think they've been traditionalists to a fault in Europe, and I think they're now seeing the potential for going back to local pubs and local breweries and trying to get away from that consolidation of the brewing industry that happened in Europe over the last 20, 30 years.

tracey peake:	Well, thank you so much for being here today, John.

john shepard:	Thank you, Tracey. It was my pleasure.

tracey peake:	Wonderful. I'm Tracey Peake. We've been speaking with Dr. John Shepard, professor of bio-processing science here at NC State. Thank you for listening to Audio Abstract.