Lots of that going on in the wine world right now. If you’re picturing yourself in a bathtub full of cold water, you’re not too far off. The term is literal, but there’s no water involved.
The cold soak is a technique that delays the onset of fermentation by keeping the must (crushed grapes) cool (yeast likes it warm). If the grapes come in at night or on a very chilly morning, it’s just a matter of keeping it that way and with stainless steel tanks, it’s very easily done. When the grapes come in warm, the most common way to chill the must down is to blanket it with dry ice (the solid form of carbon-dioxide). The cold soak usually applies to red wine. It’s a good way to get some color, flavor and tannin from the grape skins without extracting bitter seed tannin. There’s no avoiding seed tannin entirely because alcohol is a solvent, so as per a recent post, it’s important that the seeds are mature – not too bitter – before they’re harvested. One winemaker I know follows the cold soak with early pressing (separating the wine from the grape solids before fermentation is over). This is another way to minimize the extraction of seed tannins. And, one of my clients does a 3-5 day cold soak and fermentation is followed by a few weeks extended maceration (leaving the wine on the skins after fermentation is over). The idea is to get even more flavor, working on the theory that the tannins form a chain during those days or weeks, which softens the mouthfeel. That’s the great thing about wine – there aren’t a lot of rights or wrongs, unless the wine is spoiled, of course 😉 Grape juice and yeast make wine and the countless variables along the way are a matter of personal preference. When one winemaker zigs where another zags, you get a different result! Cheers! Send me your wine question For a free email subscription go to home page, right column
The Tasting Group 