Rich DeScenzo is a microbiologist with ETS Laboratories in St Helena, California and a grape chemistry expert. Rich has spent a decade researching grape genomics (examining the DNA sequences of grapes) molecular diagnostic methods and fermentation. I was attracted to the ETS booth on the trade show not by Dr DeScenzo’s scientific pedigree, but instead by a large plastic scorpion, the mascot for one of their diagnostic technologies. As he poked the scorpion, Rich told me that ETS is the biggest independent wine laboratory in the United States with about 45 employees who do the microbiological analysis for almost 90% of the domestic wine industry. Their aim is to prevent microbial spoilage at the grape, bottling or beyond stages of the wine production chain, what Rich describes as “full spectrum analysis.” The good doctor was lively and entertaining as he explained the microbiological problems that can occur during the wine making process. Here’s the first part of our conversation.
Richard DeScenzo, Microbiology Group Leader, ETS Laboratories
Danny: So if I’m a Midwest grape called the Norton and I’m not tasting too great…?
Rich: I’ve just tasted two very nice Nortons thank you! One had a little bit of Brettanomyces in it, but not bad. I tasted one yesterday too that had a little of what I might call a microbial funk in it.
Danny: Is that what produces that inside of an artichoke can taste?
Rich: Well there are lots of different ones. I’m the microbiologist so I’m very tuned into microbial spoilage and that’s what we focus on trying to help people prevent and we have all the diagnostic tools. I gave a talk yesterday (Friday 10th February) at 830am, it was the first talk early in the morning…
Danny: Nice to get it out-of-the-way?
Rich: Yeah, yeah! There were about 30 people and they came for a microbiology talk. Historically people have looked at microbiology as regards the wine industry as a forensics tool, in other words, if something goes wrong you call the microbiologist, for example if the wine starts smelling. We have the tools now that we can prevent spoilage because we can detect the organisms long before they spoil the wine. Overall I’ve tasted a number of wines here and I was very pleasantly surprised at some very nice wines. There are some that have some problems but it doesn’t matter if it’s a Norton or a Cabernet from Napa, you still have problems in the wine.
Danny: So people come to you when they have a problem but are you able to tinker with things in the wine?
Rich: We’re able to tell them what caused the problem. If we catch it before it’s a problem that’s really the power we have and what we’re seeing is a gradual shift in the industry towards pre-emptive screening instead of forensic analysis. Now with the chemistry side, the chemistry is the standard, you need to follow things, you need to know, where are my sugar levels? Is sugar dropping? Is all the sugar gone? Is my fermentation complete? Or malolactic fermentation, is it complete? That type of thing. There’s a great deal of science behind this and what’s interesting, really interesting, is that people who want to have the fewest touches on the wine, the very purest, minimal impact, those are the people who benefit most from having all the information. If you’re one of the large manufacturers and you’re adding lots of SO2 and you filter and then you sterile filter in bottling, maybe you don’t need to know as much, because it’s more like an industrial wine production, but for the folks who are really trying to do as little as possible then the more technology they use and the more helpful it is.
Danny: Is there a typical problem that wineries just starting out come to you with?
Rich: I think the biggest problems early on revolve around sanitation, and not sanitation in a way that there is anything that could possibly harm anyone, but sanitation and not understanding the difference between say cleaning something and then sterilizing or sanitizing it. So a lot of times they end up making a wine which is a nice wine and then they go to the bottle and some microbes, bacteria or yeast get into the bottle and they spoil the wine. That’s what we’ve had a lot of comments about in the context that, maybe in the first few years a winery doesn’t have a lot of natural microbial inhabitants, but over time you start building up these populations in your winery, your house strains, and then you can get bugs in there that can cause a problem in the wine.
Danny: Gosh!
Rich: And so that’s probably for the startups, other than the basics people need to know. Invariably they start having problems with microbial spoilage, that’s usually the big one, either that or oxidation, that’s the other big issue.
Danny: Can there be a fine line between the job a microbiologist like you and the task of a winemaker?
Rich: No! We’re completely different. For winemakers, their job is to keep the right microbes in and keep the bad ones out, but there’s so much more to it all in the decisions during the process, like when to harvest the grapes, how to manage the canopies, what crop load on the grapes, what yeast they select, what bacteria, what oak, what toast level. These are decisions they make along the way and we don’t really influence any of that, what we do is work specifically on the chemistry of the wine and then prevent microbial spoilage.
This is the first part of a two-part interview. In the second – and arguably more interesting part – Rich gives his views on Midwest wines and the future of the industry. Part II will be posted very soon.
