9UNP1299SD_Nick_Smith_WordPress

- Welcome, everyone to Wednesday Nite at the Lab. I'm Tom Zinnen. I work here at the UW-Madison Biotechnology Center. I also work for UW-Extension Cooperative Extension, and on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association and the UW-Madison Science Alliance. Thanks again for coming to Wednesday Nite at the Lab. We do this every Wednesday night, 50 times a year. Tonight, it's my pleasure to introduce to you Nick Smith. 

He is the brand new enologist here at UW-Madison in the Department of Food Science. He was born in Lionel Lakes, Minnesota, and went to the University of Minnesota for his undergraduate on the Minneapolis campus. Then he got his enology training at Oregon State University, worked for a couple of years in California, came back to the Twin Cities to get a master's degree in food science on the St. 

Paul campus, and then in April came to Madison to be, as far as I know, the first dedicated enologist here at UW-Madison. I think it's a great time to be thinking about grapes and wine here in Wisconsin. Please join me in welcoming Nick Smith to Wednesday Nite at the Lab. 

(Applause)

- Thanks, Tom. Good evening. Happy you all could come out tonight and talk about some Wisconsin wine. Occasionally I have a little trouble switching to Wisconsin since for so many years I said Minnesota. 

(Laughter)

Forgive me if I make a little slip up there.

As Tom mentioned, I am the first dedicated enologist here at University of Wisconsin, part of the brand new Fermentation Sciences program, which I will introduce shortly here. Kind of a rundown of what we'll talk about tonight. I'm going to introduce myself a little bit, although Tom did a very good job of that already, as well as the new program and the new project that we have going here at the University of Wisconsin. 

And then kind of go into discussions of cold climate grapes, what makes them unique, how those uniquenesses impact wine production and what I study and research and work with the industry on improving, talking about a bit about quality and what that really means, and then talking about the research that we have going on here at the University of Wisconsin, both of what I'm doing and a bit of what the horticulture department is doing as well as the genetics department here, right above us actually. 

So it's a brand new position. I started March 28th. So I've only been here a few months. So it's part of the Fermentation Sciences program. Dr. Jim Steele is the chair of that program. We're getting that started so I'm basically the first employee of that program as well. So they're doing a lot of research on beer and wine production up there. What makes this interesting is this position was started by an initiative from the industry itself. 

It is not a university based, they did not sponsor it initially. The Wisconsin Vintners Association, along with the Wisconsin Winery Association, the Wisconsin Grape Growers Association, got together, teamed up, and wrote a grant to fund this position. And we got funding for several years to get the position started. What's fascinating about this from my perspective, having worked in other states in the industry, is that the first one on there is the Amateur Wine Association out of Milwaukee. 

So to have an amateur wine association be one of the biggest supporters and proponents of our program I think is pretty amazing. And they've been very helpful in getting this all started and organized. So the position itself main focus is on improving the quality of Wisconsin wine. So my main objectives are to go out, meet with wineries, address quality concerns, do analysis, as well as formulate research to help improve the overall quality of Wisconsin wine and grapes. 

My background, as Tom mentioned, is I originally got my undergraduate degree in finance and marketing from the University of Minnesota's Carlson School of Management, ended up continuing on in food science for a while. During that time, I spent a year at Oregon State studying food science, finished up that year, and the headed south into California where I started an internship a year ago, 10 years ago in August of 2015. That's when I kind of got full on into wine. 

So I worked at a facility that used to be owned by Ste. Michelle Wine Estates out of Hopland, California. Finished my internship there and got a job, position at Beringer Vineyards working as a wine chemist doing lots of lab analysis. Before I actually went out west, I actually did research at the University of Minnesota for the enologist who was there. 

She informed me that there was a position opening up at the University of Minnesota, applied for that position, and eventually moved back to the University of Minnesota about 2006 to do research wine production there. I was the research winemaker and wine analyst for the breeding program.

Briefly between here and University of Minnesota I did go back and do commercial wine production and cider production at Four Daughters Winery and Vineyard down in Rochester, Minnesota. And then when this position opened up, I applied and accepted and shortly thereafter moved here. So it was a very quick succession.

Before we talk about Wisconsin wine history, we're all here tonight so I'm assuming most of you are wine consumers. Is that correct? 
(Laughter)

 All right, so, next question is, how many of you are actually avid consumers of Wisconsin wine? A very good show of hands. Great. I ask those questions in Minnesota and don't always get the same response. So that's good. They've been growing grapes for quite a long time on some level in Wisconsin since the 1840s when Agoston started the vineyard not far north of here, what eventually would become Wollersheim. And the first commercial winery in the state started in 1867. 

So we're going on close to 50 years of having commercial wine production in the state of Wisconsin. Wollersheim started in 1972. They're prominent because they are the largest winery here in Wisconsin. There's been several viticulture areas that have been named and established in Wisconsin viticulture areas are areas recognized by the federal government for having very specific wine growing, grape growing characteristics. 

So it's good for marketing and differentiation of the wineries and grapes grown in those areas. University of Wisconsin didn't really start getting into grape research probably around 2000, 2005, 2008 when they started establishing vineyards at the agricultural research sites around the state, one of which is over here in west Madison. And then in 2015, just shortly not long ago, that's when I came on board. So that's kind of the history of Wisconsin wine. A little bit of statistics. 

Currently, there are actually about 110 wineries licensed in the state of Wisconsin. So you can see from several years ago, that's quite an increase of over 20 wineries. We're growing roughly five to 10 wineries every single year. That's been consistent for the last five or 10 years. Up to probably 700-plus acres of grapes. I would say probably more than that. It's a little hard to get a good estimate since a lot of small growers don't report how many acres they have. 

You can see in the last 13 years, they've more than doubled the size and number of grapes grown here in Wisconsin.

The five largest wineries are Wollersheim, Door 44, Parallel 44, which are the same business, Danzinger Vineyards, Door Peninsula and Elmaro. A couple wineries that I've kind of gotten into recently are Dancing Dragonfly and Villa Bellezza. I think those will probably move into the top five here pretty soon. We should be proud of some of our wineries, particularly Wollersheim Winery. It's one of the largest independent held wineries outside of California, including Oregon and Washington. 

So I think it's about 13th. They're producing 100,000 cases, roughly, every year.

We'll talk a bit about cold climate grapes. Some of you are probably familiar with these particular varieties. Worked a lot with these varieties when I was at the University of Minnesota. Marquette had just gotten introduced when I started there. So I'm probably one of the few people who has the most experience of actually producing that grape.

So the cold climate grapes, these hybrids, they're an interspecific cross between either Vitis labrusca or Vitis riparia and the typical wine grapes of Vitis vinifera. Vitis vinifera are your Chardonnays, your Merlots, and your Cabernets. Vitis riparia is also known as river grapes since that's where it predominately grows are in rivers along the riverbanks. Very small berries, small clusters, dark juice, high acid, very high sugar, herbaceous flavor. 

I talk about these characteristics because a lot of this genetics get carried over into our other varieties that we're trying to grow now. These are the type of things that we have to learn how to handle when we try to make these into wine. On the other side there's labrusca varieties which tend to be a little bit lower in sugar, but they have a very specific flavor profile. The University of Minnesota has relied a lot on Vitis riparia for its cold climate genetics. 

Whereas, Elmer Swenson, who I'll mention again here shortly, since he's a Wisconsin based grape breeder, he used a lot of labrusca based. When we think of hybrids we think of them in kind of one general camp, but there's really two sort of separate angles that they can take. And the challenges that they present aren't quite all the same. So you can see the Vitis riparia is grown pretty much native throughout the Upper Midwest and Canada and down into even Texas. 

You can see from this picture maybe just how tiny and scraggly those grape clusters are. So they're kind of hard to deal with. Very tiny berries. Lots of pigment. It takes a lot of picking to get any real production out of those.

So, in terms of breeding and varieties you might see here in the Wisconsin market, MarÈchal Foch and LÈon Millot... are things that are grown quite a bit here in the southeastern part of Wisconsin. Wollersheim grows a lot of these. Botham Vineyard grows both of these pretty extensively. And they've been around since 1910 or in the 1910s when a French breeder named Eugene Kuhlmann produced those varieties, and they've been very popular ever since. They're kind of the basis for cold climate wine production. And in Minnesota and north and west of here, they don't grow as well as they do here. 

So other breeders, including the University of Minnesota, have been working on trying to improve on those and create other varieties that are better suited for these climates. The University of Minnesota has been working on grapes for a very long period of time, started breeding roughly in 1905, and started coming out with their first round of grapes that they released in about 1944. I highlighted Bluebell there since that's one you occasionally do see wineries producing in the wine. 

I don't know if the other three really even exist anymore. I think they might actually be extinct. But the initial emphasis of the program was on table grapes, juice, jelly production. It wasn't until about the '70s or '80s when they actually shift focus and put more energy and effort into actually wine grape production. Their first wine grape was released in '96 called-- which many of you who have been to wineries around the state have probably seen.

They're actually hinting that they'll release a new variety, at least when I was still working there they hinted at it. I don't know what the current status of that is, but hopefully they'll have that out soon.

On top of the university breeders, there's been a lot of private breeders. There's a lot of people with an interest in growing these varieties. So way back even in the 1870s, Lewis Swelter created numerous varieties, but one of his biggest ones was Beta, which would have been one of the most popular varieties grown in the Upper Midwest prior to Prohibition and was actually pretty widely grown in both Minnesota and Iowa. David MacGregor is a private breeder. 

He came up with Petite Amie, which isn't necessarily very popular here in Wisconsin, but you do find some of it in Minnesota. After that, of course, is Tom Plocher. He created the Petite Pearl, which is becoming a popular grape grown, or a very interested variety, here in Wisconsin. It's a relatively new variety so we don't know a great deal about it. We got some of those grapes from the research center this year. So we'll get some new information on those. 

And he's planning to breed at least a couple new varieties here this year. One of the other major universities that does grape breeding is also New York. I mention them mostly because of varieties like Traminette. You might see those in local wineries. Traminette is not cold hardy enough for Wisconsin, but they do grow in Illinois and Arkansas. So you occasionally do see them in tasting rooms around Wisconsin.

I can't talk about Wisconsin grape breeding without mentioning Elmer Swenson, who many consider the godfather of grape breeding, especially the Wisconsin supporters. It should be noted, though, that he did work for the University of Minnesota for about 10 years, and while he was there they joint released two varieties. Edelweiss, which is a common grape variety that is turned into wine, particularly here and Nebraska, as well as Swenson Red. And he created a whole slew of other grape varieties. 

He also produced and released St. Pepin, a popular one, and Brianna around here and a few of those other varieties you might see when you're out and about in tasting rooms.

So, what's the general differences between these varieties? Well, one is color. In terms of red grapes, the color intensity and the pigmentation is very intense compared to, say, your average vinifera.

One of the things that they have besides pigment in the skins is also their pigmented pulp. Cabernet and Pinot noir have a clear pulp. Our varieties actually have a pigmented pulp. So when you press these things out, they're actually very dark right from the beginning. And the white grapes, they have a bit of a yellow tint, but they also can brown a bit. So there's a high polyphenol oxidase activity. 

If you ever cut open an apple or a banana starts to turn brown, so those enzymes also exist in grapes. The hybrids seem to have a lot more of those then many of the vinifera. One thing you'll definitely notice if you try cold climate wines is that they tend to be a lot more acidic. Quite a bit more than Vitis vinifera. Titratable acidity, 11 grams per liter to 15 to 17 grams per liter. A majority of that is actually malic acid, where vinifera is typically 50/50. 

It's got an even split of tartaric to malic, where some of these varieties, like La Crescent, can be almost 75% malic acid, which is important when we discuss later how we manage the acid in the winery. So just kind of a general summary of some titratable acidities just to give you an idea that Frontenac is roughly two to three times more acidic than your average red table wine. Sometimes three times as much. 

So these are some of the challenges that we have to embrace and work with when we're making wines from these varieties. But there are other varieties out there, other styles of wine out there that could fit those quite well. So, sparkling wine is probably a good use for some of these varieties.

One other difference is the amount of tannin in the variety, especially red grapes. Very little tannins in the finished wine. And it's almost completely opposite. So, vinifera have a great deal of tannins and not nearly as much anthocyanin content, where the cold climate varieties have a tremendous amount of anthocyanins and not a lot of tannins. So theirs is kind of reversed. A lot of people would like to see more tannins in their varieties. 

I kind of prefer the fact that we don't have a lot of tannin in that. If we had high tannin and high acid, it'd be a very difficult wine to work with, even more than it already is. Acid tends to increase the perception of tannins, as well as tannins increasing the perception of acid. So having both of those would be a bit challenging.

The sugar content can vary a bit depending on the variety, it's parentage, and where it's grown. One of the challenges I had when I was in Minnesota is that the varieties accumulated a lot of sugar. So it could be a very alcoholic wine or put a lot of stress on these. Don't seem to have that issue down here in Wisconsin, in this part of Wisconsin as much, but those are some of the issues you can have. The fact that it is lower is helpful for different types and different styles of wines. 

And some of the other properties, are just for processing scape.

Some of the difficulties is some of the labrusca based ones have a slip skin. So it's a very difficult pulp, and it will just slip right out of the skin, which makes pressing extremely difficult for those varieties.

But we're here to talk about embracing cold climate wine. So things that we do well, these varieties are almost all very aromatic. Very distinct. Unmistakeable aroma profiles for these wines, which I think is great and people need to kind of embrace that and promote that a little more. And things we can do with acidic wine with low tannin and low sugar content is we can make things like sparkling wine. It's a perfect option for our varieties as is. As well as things like Rosé. 

I mention here and up and coming style called Pet Nat, which is a carbonated form of sparkling wine but not nearly as carbonated. So what they'll do is they'll take wine as it's nearing fermentation and bottle it. And the residual sugar will ferment out, much like a carbonated bottled conditioned beer. So it's a low carbonated dry wine, which I hear are quite nice. It's an up and coming trend I see a lot of it coming out of Europe right now. 

Dessert wines and ports also work very well with our varieties. Two of the largest and fastest growing markets in the wine world are Sauvignon Blanc, which typically are dry acidic wines, as well as Rosés, which things like Marquette and Frontenac can make very nice Rosés. Now we say that the Midwest is kind of like the wild west of grape growing. There are no limits. There's nothing telling us what we can and can't do. 

So hopefully some creativity and adventurous people will come out and create some new things.

So some statistics on both Sauvignon Blanc and Rosé. You can see that the blended table market was up 33% last year. So I think that's a good opportunity for wineries here to take advantage of that, as well as to maybe embrace some of the lesser sweet styles, like Sauvignon Blanc and New Zealand ones, which tend to be dry and acidic.

I should note that while the blush category is up 33%, White Zinfandel was actually down 7% over the last year.

All that is great, but one of the things I'm here for is to talk about quality. So, quality in Wisconsin wine. My purpose is to help improve the quality of Wisconsin wine, identifying some of the top quality challenges and issues. So last, when I first got here, I surveyed all the wineries in the state to get an idea the things they thought were the top quality challenges for the state of Wisconsin. 

These are the issues that they brought up, and they're the typical culprits of almost any wine production area out there. So, oxidation, sulfide production, volatile acidity, quality of fruit. A little less pressing is just wine style, matching the fruit with the type of wine or good style of wine, and just issues of fruit growing and wine quality So not just figuring out how to make the grapes survive, but how to grow the grapes in a way that they can actually produce better wine. 

So there's like two layers there that we're trying to get to, the first layer and then the second layer.

But what is quality mean? And that's one of the challenges of my position is that quality itself is kind of a vague term, and it varies a lot by individual and who you're talking to. So someone in the service industry might talk about complexity, body, weight, food and wine pairing. 

The Sauvignon Blanc from New Zealand tastes like it should be a Sauvignon Blanc from New Zealand, or if the flavor profile is off, integration and harmony and all these terms that they like to use for their wine quality. From a producer perspective, is it free from faults? Is it bottle stable? Did it produce the type of wine that I was trying to make? That might be what producers are looking for in terms of what they define quality.

Here's two drastically different types of wine. Screaming Eagle being a thousand dollar-plus per bottle cult wine out of California and Beringer producing and $8 bottle of White Zin, When we talk about quality, which one has more quality? Which is a higher quality wine? Well, it depends on how you want to look at it. You might say the Screaming Eagle, because of its complexities and where it's from, is a high quality wine. 

But I could easily say that Beringer is a high quality wine because that wine, I did tons of analysis on that wine so I can tell you that a lot of effort and research goes into that wine production. Very careful about it. A lot of effort goes into it. When you got pick up a bottle of White Zin from Beringer off the shelf, one bottle could be produced last month, the other bottle could have been bottled six months ago, they'll be identical pretty much. That's a difficult feat to achieve. 

That reproducibility that they have should not be understated. So it depends on what you determine quality to be. When you start talking about wine faults and things that are bad quality, it gets to be a bit of fine line between what constitutes complexity and what's objectionable So somebody might like a bit of a-- character in their wine; someone else might think it's the worst thing ever. Where that line is drawn is really dependent upon you as an individual. Your experience with wine. 

How much wine have you drank? How many different regions have you drank it from in your history with that? As well as perspective. The example that I saw of perspective is, say, two individuals smell rosemary in a wine. One person might associate that with a culinary rosemary chicken or some other food application, but another person might compare that with a personal care product, like a lotion. 

So which would you rather have your wine smell like? So, two people smelling the same thing are going to have two very different ideas on whether they like that wine or not. And then you get into physiology, which is every one of us smells wine differently. What we're sensitive to and not sensitive to is very individual. So every person's experience is unique. It makes quality kind of a challenge to define. So I refer to Dr. 

Bisson out of UC Davis who defined GRAY, which is generally recognized as yucky. So these are the compounds I focus on when it comes to Wisconsin wine. As we mentioned before, here's a few examples or some of the common examples of issues you might find in wine and cider. 

So, sulfides, oxidation and acid aldehyde, cork taint, which is a compound called trichloroanisole, or TCA if you want to sound hip for your next dinner party, Brettanomyces, 4-ethylphenol, 4-ethylguaiacol, acidic acid, ethyl acetate, VA, and a few other things we'll talk about. I don't know if that is very visible from back there, but sulfides are not a very pleasant compound. They're usually a result of stressed yeast in a fermentation. 

They start kicking out, start out as rotten eggs all the way down to canned vegetables. So these are kind of some of the initial areas of some wine flaws that you might come across. Definitely probably not acceptable except in very tiny amounts.

Another area that's a problem is oxygen pressure on the wine during storage as well as stress fermentations. So if the wine is stored in an environment that has a lot of oxygen pressure on it, whether it is a low grade plastic tank where the oxygen can transmit through the side or a lot of head space, ethanol can be converted over to acid aldehyde. Acid aldehyde at low levels can give kind of a fruitier aspect to your wine. Higher levels start to smell like rotten apples. 

Further than that I get airplane glue, model airplane glue aroma. 

(Laughter)

 Nuttiness but generally considered a flaw, unless you're sherry where it's expected and needs to be in very high levels. So wine flaws are always in kind of an interesting area depending on what you're trying to achieve. 

This is a common sort of flaw that we find in Wisconsin just because of proper application of sulfur dioxide as well as minimizing oxygen exposure, which, as you get on smaller and smaller scales and more surface area, tends to be a much bigger challenge for small wineries to maintain.

So TCA is a combination of mold and chlorine. So a little bit of mold plus any sort of chlorine in the environment, most people think it's based from cork, but it could be from the winery itself. If there's any mold and they use a chlorinated cleaning component, you can get winery borne TCA as well.

Not a very pleasant compound. It's super potent. It's parts per trillion sensitivity. Like as low as five parts per trillion people can start to pick up on this compound. So like one gram in an Olympic sized swimming pool is what we can detect. Cork is, you can see where you might get a little bit of mold or whatever from the cork. That's an agricultural product. So, some unpleasant compounds from Brettanomyces. Brettanomyces is a spoilage yeast. It's present in the environment. 

It's on the grapes. If a winemaker is not in a situation where they have a high pH wine, Brettanomyces thrives well in higher pH environments. Low pH, they don't survive as well. Sulfides are good at maintaining them. But they can produce, and if there's a lot of residual nitrogen left, one of the things I didn't mention before was that a lot of these hybrids actually have a lot of nitrogen content. You need a certain amount of nitrogen content to maintain a healthy fermentation. 

In a lot of cases, depending on where it's grown, I've seen fruit out of Iowa have yeast assimilable nitrogen content, or primary nitrogen content that the yeast use, at six to seven times what the yeast actually needs. A lot of that gets leftover in the final fermentation. If you're not properly maintaining your wine, it can feed spoilage organisms pretty well. it can feed spoilage organisms pretty well. And then you get some pretty awful things. 

Unless, of course, you like sour beer, then those are the things you're looking for. It depends in what you're into.

Another concern here in Wisconsin and a lot of places is acidic acid and the conversion of the acidic acid to ethyl acetate, which smells like nail polish remover.

Acidic acid, if you've got a lot of oxygen present on your wine and you're not properly sulfiding it, then the acetobater can take over and start kicking it out. Otherwise, stress yeast, particularly ice wines, can get a bit of VA naturally. It's kind of a natural process for that.

This mousiness is typically associated with cider. I kind of bring it up because it's an interesting particular compound because you can't smell it at the cider pH. So until you taste it, you won't know it's there. So it's kind of a horrible shock sort of reality.

The pH, and it depends on the individual, so if you're an individual who has a higher pH saliva, it raises the pH of the wine or the cider, and then it becomes nice and noticeable on the finish of your palate. It's not the greatest way to finish a sip of wine.

Some other common things are protein formation. Haze formation due to protein instability due to heating of the wine. Potassium bitartrate are obviously little crystals you might get if you chill wine. Wineries still put a lot of effort to remove those from wine. Apparently consumers still might mistake them for glass particles. It's a lot of effort to do that. A lot of energy goes into chilling wine down and getting the potassium bitartrate to settle out of it simply for cosmetic reasons. 

You do get a little bit of acid reduction from that. So wineries who like to do it kind of get a little bit, take down their acidity a little bit.

But, again, depending on who you are, sometimes hazes are good. A couple of kind of recent, last five or 10 years, popular wines is a thing called orange wine. So it's white wine that's been fermented on its skins. Some of it has been fully filtered and processed out to look like a clear wine, but some of it's just left raw, hazy, and kind of natural. So there's a whole group of people that get into that. I talked about Pet Nat a little bit. 

So you get a wine that has sediment in it because of that refermentation of the yeast in the bottle. So the world is kind of changing in the world of wine of what's considered acceptable and unacceptable anymore. So you can see the orange wine on

top there is very cloudy. That's intentional.

So in terms of Wisconsin wine and whether or not these GRAY issues are more common, it's hard to say. I've been to wine regions all over the country and the world, and I've experienced and encountered these problems everywhere. The typical issues obviously are experience in both just recognizing what these flaws are and how to prevent them in production. Expertise. 

One of the things recognizing that commercial wine production is a much different animal than home wine production, which can be a challenge for some people to make that transition and realizing there's a whole new world of technology that they have to learn how to deal with to get better at producing a commercial wine.

A lot of people get into the winemaking world without having a scientific background. Wine production is a very scientific thing. So you'll get people who are close to retirement, decide they want to open a winery, probably haven't had a chemistry class since sophomore year of high school. It makes things a little challenging at times. It's a very capital intensive and expensive proposition to start a winery. 

Having proper equipment and laboratory equipment to do quality wine production can be a bit of a challenge.

So, things we do here. Well, we have analytical services. So we can do some of the higher end analysis for you. I do site visits. I go out and I consult with wineries and help them work through their challenges. If they wish to contact me and work on those, we'll do that. Otherwise, I hold workshops and educational events where we'll address specific winemaking issues. 

And then we're working on some various cold climate specific research to improve the quality of the wine, to understand how we can make wine out of these varieties. So, horticulture has probably presented here, I'm pretty sure at least once or twice, but some of the things they're working on is the impact of fruit shading and sun exposure on the quality of fruit. 

So they're going out and pulling the leaves off and leaving some vines very well shaded, some vines very well exposed, and looking at kind of the differences of what the chemistry of those varieties are. They're also looking at trellising, different types of trellises. Best ways to grow various varieties. One type of trellis system might not work well with one variety than another. They're looking at some pest management as well as disease management options as well.

So on our side over in enology, it was a pretty easy thing to take the fruit shading thing and let's make some wine out of it and we can compare the flavor of that. It's hard to say whether one is better than the other based on your personal preferences, but at least we'll be able to give these examples of shading to winemakers and they can make decisions about the style of wine they want to choose based on the results that we can give them. 

Looking at the impact of skin contact and fermentation temperature. And then I will hopefully focus on the future of wine and research that I was doing at the University of Minnesota, which was biological acid management using yeast and bacteria to help manage acidity in wine and dealing with that high malic acid content we have here. I guess one of my ultimate goals is to identify the flavor compounds in cold climate grapes and understand how viticulture and enology influences those. 

So we can give winemakers a range of options on how to make their wine based on how flavor is influenced.

So some of the research we're doing right now with an undergraduate group doing their senior project is actually looking at skin temperature and skin contact and fermentation temperature during red wine production. Traditional red wine production, seven to 14 days of skin contact before they press it out. Warmer temperatures, 75 to 85 degrees Fahrenheit. And the goal there is to extract as much tannins and phenols and color and flavors from the grapes. 

One of the things I mentioned earlier is that we don't have a lot of tannins and we have a lot of color. It doesn't make sense for us to be using standard vinifera practices to be making wine.

So these undergraduates, a very ambitious group of undergraduates that we have in the department, were evaluating the color, phenolic content, and flavor differences in two varieties of wine, Marquette and Frontenac, and looking at cool fermented and ambient temperature fermentations at different skin contact times.

They're still in process with that. Hopefully we'll have those results and we can bring it to Winemakers for their annual meeting this winter.

It's going to be impossible to read, but there's an arrow pointing at the skin and then there's a long list of things that we find in the skin. That's where the skin contact research comes into play here is, are all those compounds in the skins of hybrid varieties things we actually want in the wine? And is it better to do a shorter skin contact versus a longer skin contact fermentation?

We know that from other research that exposing the fruit to more sun does lower acidity, gives it more sugar, and increases the phenolic content and gives it a different flavor profile. The three varieties that we're looking at for this year are Marquette, Frontenac, and Petite Pearl.

Horticulture is examining the basic chemistry of these things throughout the growing season. And we're going to take them, we're fermenting them right now, and we're going to look at the flavor differences and see if there is a change in the kind of hybrid herbaceousness and vegetable character of some of these varieties, and whether or not shading or unshading is actually a positive or negative attribute.

So in terms of tannins, Cornell University is doing a lot of research on tannins. I say there's not a lot of tannins in the final wine, but there's actually a fair amount of tannins in the grapes themselves. An active area of research is trying to figure out why there's not tannin in the final wine. 

There are hypotheses, and research indicates that there's a grape solid, a grape particle that during fermentation is binding with the tannins and is causing those tannins to settle out of the fermentation. They've done research where they've added tannins at the start of the fermentation and measured how much tannins were afterward, and it takes a tremendous amount of tannins to get any result. So these particles are very powerful and very active.

So research that I've done quite a bit of back in Minnesota and will continue to do so moving forward here at the University of Wisconsin is looking at acid management because one of the things that we're having one of the biggest challenges we have are the high acidity of these grapes and grape varieties, particularly malic acid. It's not just so much purely sourness that we got to worry about, but it's the interaction of acid with other compounds. 

So the more acid we have in there, the more likely you're going to taste some of the bitterness compounds that might be present and the more likely you're going to have some astringency because malic acid itself has an astringent character. So in terms of what we have available to us to manage acidity, there's really, once it gets to the winery, there's a couple, a few methods we can deal, use. So there's some chemical methods, and then there's using biology.

So as far as chemical deacidification, we have potassium bicarbonate, calcium carbonate or chalk. Otherwise, you can use water and try to reduce acidity that way, or add a lower acid. Grape to it. In terms of biological deacidification, we have the bacteria in yeast.

So potassium bicarbonate, calcium carbonate are two of the main ones.

The important factor to realize there is that most of those only work on tartaric acid. They won't reduce the malic acid content. So if you have a variety of lots of malic acid, we can't really reduce that acid very far. And it leaves a much higher level

of malic acid ratio there, which kind of gives it a more harshness to the wine.

So we're trying to use biological methods to reduce acidity. We're looking at yeast and bacteria that convert malic acid to some other byproduct. So, bacteria convert malic acid to lactic acid, and then there's yeast that convert malic acid to ethanol.

And we can do that, and there are yeast strains that have been identified that do that very well. There's some nontraditional wine strains. So Saccharomyces is the traditional strain we use for wine production and beer production. But there's a strain of yeast called Schizosaccharomyces pombe, which does a great amount of malic to ethanol fermentation. 

And then research here potentially in the genetics department might identify some yeast strains and produce some yeast strains that can do some biological acid management as well. So there are certain strains out there that have been identified that do some level of acid reduction.

71B I've used in the past can reduce acidity by two grams per liter, which is a significant amount of acid reduction.

Then there's malolactic fermentation using malolactic bacteria. And, besides acid reduction, winemakers use malolactic bacteria for flavor and style as well as microbial stability. That's just one less thing that an organism can utilize from fermentation once it's gotten bottled. And there's a range of organisms out there capable of malolactic fermentation. Lots of lactic acid bacteria. A strain that we commercially use is Oenococcus. 

So malolactic fermentation is not really actually a fermentation. It's kind of a misnomer. Most fermentations take sugar and convert it to an acid so it actually increases the acidity of what you're trying to do. So malolactic fermentation is actually reducing the acidity, and it does that using an enzyme that converts to malic acid or lactic acid.

Some other byproducts or other compounds there. It can also begin to chew on and use to produce other compounds. It can break citric acid down into diacetyl and pyruvate and acidic acid. I bring up diacetyl because it's a compound that's produced and it masks fruity aroma in wine. So we look at using bacteria to manage acidity in wine. This is a byproduct that's a negative aspect. 

So how do we manage your diacetyl production and malolactic fermentation so that it doesn't decrease the fruitiness of wine? Especially if you're going to use it on Rosé or a white wine where you want to enhance fruitiness as much as possible.

A couple of formulas. Always feels to good to throw some of those on there. But, basically, we're converting malic acid, lactic acid just by using the enzyme to cleave off one of the carbon groups on the malic acid.

And so the research that I look into then is the timing of malolactic bacteria additions. One of the reasons why we look into that is that we know that yeast can convert diacetyl to another compound that's not nearly as strong smelling. It doesn't have as nice a name as diacetyl, 2, 3-butanediol.

It's helpful to know that if the yeast is present we can alter the timing of malolactic fermentation such that we can remove that diacetyl and be able to apply it to fruity wines that we don't want the diacetyl mass character.

The challenge, though, is that a lot of people around here make sweet wines, and then to prevent further fermentation they'll use the compound potassium sorbate.

It inhibits further yeast activity in the wine. The only problem is is that they're using that typically because they don't feel confident enough in their sterile filtration to prevent further fermentation once the wine is bottled.

Consequently, if there is a bacterial infection or a bacterial present with wines that have potassium sorbate, then there's a geranium taint issue that can result. So they convert that sorbic acid into a compound that smells a lot like geranium leaves.

When I was at the University of Minnesota, my graduate research project was looking at malolactic bacteria additions and timing on Marquette wine production. And one of the things I found was that it did reduce the time of malolactic fermentation completion. That's another advantage of a co-inoculation strategy, which is adding bacteria within 24 hours after adding your yeast versus the traditional method, which is to add bacteria after alcoholic fermentation is completed. 

The impact, no impact on the liking of the wine and it reduced malolactic fermentation overall time. So, knowing that there's all these advantages to using bacteria, looking at how we can apply that to white and sweet wine production would be great for the Wisconsin wine industry. The other biological method that's out there is Schizosaccharomyces pombe, which is a commercial product under ProMalic. It's naturally considered a spoilage organism. 

So what this company did was encapsulate it in an alginate shell. So we can put them into these mesh bags, add them to the wine. It starts doing the malo to ethanol fermentation, and then once we're complete or reached the desired level of acid reduction, we can pull it out and hopefully take all that yeast with us so that it doesn't result in some of the negative sensory aspects that people believe it can produce.

I would like to research that a bit further and actually look at other strains and see if there's a way to actually use it in its natural form without the alginate shell to see if we can produce wines that have low acid content. I've used the ProMalic in the past and have had some success with it. So I've taken La Crescent that had a TA, titratable acidity probably in the 12 to 14 range, and had a final product about 6.5 grams per liter. So it does work, and it can work quite well. 

But just a matter of what are the fermentation conditions that we can succeed with that as well as minimizing flavors and trying to tailor that to specific wine styles.

At one point there was a group of researchers out of British Columbia who actually took both the aspects of Oenococcus and S. pombe and created a genetically modified yeast called MLO1. It was on the market for a while. It got approved by the Tobacco, Tax, and Trade Bureau. I believe it's still potentially out there. 

This was originally sold under the Red Star brand, which eventually got bought out by a French company called Linares French aren't very happy about genetically modified creatures so this kind of disappeared from the market after that merger. But it is something that was out there and was approved by the TTB.

One of the things that we hopefully can develop here is that the Hittinger Lab upstairs has found ways to create some novel yeast strains under a new technology. So right now it's being applied mainly to beer production but could some of these yeasts actually enhance and produce interesting wines and ciders. So hopefully we'll be able to start researching that in the future as well.

So, embracing the cold climate wine production, looking at and identifying processing techniques that influence flavor, managing acidity, coming up with some new yeast strains. And I like to say there's a lot of room for experimentation and creativity in this industry. Canada, for example, some researchers up there are looking at grape drying. The Amarone raisin style wine production. 

Instead of just taking grapes and putting them into the attic of a barn and blowing air through them, they've looked at a wide range of doing that, including using retired tobacco dryers to rapidly dry down grapes and create different types of wines and take advantage of the properties that those grapes have available to them. So there's opportunities out there, and there's not restrictions. Not Europe where you have to grow your grapes a certain way, produce your wines a certain way. 

There's all sorts of options and opportunities. So, if you're, I guess, an adventurous sort, growing grapes and wine and making wine here in Wisconsin is kind of a great place to be. And with that, I thank you all for coming. There's my contact information, if you have any other questions about making wine in Wisconsin. 
(Applause)