Issue link: http://winesandvines.uberflip.com/i/543749
WINEMAKER INTERVIEW August 2015 WINES&VINES 45 avoided the Saran/tin liner because of reduction problems in the wine. That seems to be a pretty well-documented phenomenon. For some wine styles it fits, but not for what we are doing. Our first screwcap bottlings used the Saranex liner. We used it because it let in about the same amount of air as a natural cork. However, we now have moved to the VinPerfect screwcap. I think their liner construction is state of the art. They give the winemaker the ability to control the oxygen transmission rate (OTR) level and have a consistent OTR level. There are studies that show Saranex liners can have a wide OTR range, which you don't see with VinPerfect. Q How do you decide which closure to use with a particular wine? Fletcher: The closure is part of the package look, so that decision is made in concert with our marketing and sales departments. In a perfect world, I personally would use VinPer- fect ROTE closures on everything we make. But there are a lot of other considerations that go into the decision, and consumer acceptance is a major one. I think you'll see more screw- caps on expensive wines as the consumer be- comes more comfortable with the concept. Q You've done trials with a variety of screwcap liners. What have you found? Fletcher: Like most wineries, we started doing closure trials many years ago. We have a trial at Chimney Rock using cork, Saran/tin and Saranex screwcaps on Cabernet Sauvignon and Sauvignon Blanc that goes back to 2006. We have older studies but not as well con- trolled. For the Sauvignon Blanc, I don't think there is any question: The Saranex-lined screwcap gave the best results. The last time we tasted the trial, it was everyone's prefer- ence. I don't think it is as clear-cut with the reds. The cork-finished wine had aged in a very nice way. The Saranex-lined screwcapped wine was fruitier and seemed younger. There was a lively discussion about preference. We also have a two-year trial at Terlato comparing all the different screwcap liners that were available at the time. The trial is looking at all the VinPerfect liners along with Saran/ tin and Saranex. I want to see if there is an ideal OTR for different styles of wine. When I set up the trial, I thought I wanted a liner with the least OTR that didn't cause reduction. How- ever, after two years I'm not sure that should be the objective. One of the wines with a Vin- Perfect liner that lets in more air than a cork had developed more complexity without any apparent oxidation. So maybe wines for early consumption could be bottled using this kind of liner. Ask me the question again in five years—maybe I'll know by then. Q Do you need to adjust your sulfur di- oxide additions? Fletcher: No, you don't need to adjust SO 2 levels, but VinPerfect screwcaps give you the opportunity to consider it. But before you consider changing SO 2 levels, you need to make sure you have removed most of the oxy- gen from the headspace. There is a lot more headspace in a screwcapped bottle than a corked bottle, so you need to make sure it isn't full of oxygen. The only way we have found to solve that problem is by using a liq- uid nitrogen drop system from Chart (Indus- tries) Liquid Nitrogen Dosing between the filler and capper. Once you have solved that problem, you can consider different levels of SO 2 in the wine. If you use a screwcap liner with a low OTR, why not lower the free SO 2 ? The liner will allow less oxygen into the bot- tle, so maybe you can get away with less SO 2 to preserve it. However, we haven't played with it much ourselves. A resident of the Santa Cruz Mountains, Laurie Daniel has been a journalist for more than 35 years. She has been writing about wine for publications for more than 21 years and has been a Wines & Vines contributor since 2000. MEASURING GRAPEVINE EVAPOTRANSPIRATION TO SAVE WATER California wine producers are looking for ways to conserve water in light of the state's historic drought, and Terlato Wine Group is no exception. To that end, the company in 2014 started testing new technology for measuring water use by the vines in several vineyards. "This new technology developed by Tule Technologies is going to help make irrigation decisions easier," says Doug Fletcher, Terlato's vice president of wine- making. "It's pretty amazing technology. It measures the crop evapotranspiration rate (ETc) directly." Fletcher notes that previously the only way to measure the ETc directly had been by using a lysimeter, which was expensive and cumbersome. "Using the surface-renewal device from Tule is like having a lysimeter in every vineyard," Fletcher says. "For the first time, I can measure the real plant water use. By using this device in conjunction with soil moisture data, we are starting to get a handle on how much to irrigate." He says he's discovered that "plants have access to water we hadn't thought about," which has allowed reduced water use. "In the past, I guessed at how much to irrigate. Now I know how much water to use." Tule sensors measure crop evapotranspiration directly. Bottles are filled and sealed with a natural cork closure on the Terlato Wine Group's bottling line. TOP: ALAN WELLS