So in our last blog I debated (pretty inconclusively I might add) on the Alcohol content in wine… But as promised here are some of the methods used to reduce high alcohol levels in wine. This can be done either in the Vineyard when the grapes are ripening in order to reduce Sugar levels in the grapes, or in the winery to remove some of the alcohol. Hopefully this might bring us closer to an opinion on the whole thing!
In the Vineyard: So if the sun is the problem for increasing sugar levels than why not simply move to a cooler climate?? Nearer the ocean, or at high altitude should do it… But this is only really practical if you are starting off… and looking for a good place to plant. If you’ve already been growing grapes in one area for a while then changing could be pretty expensive. Another idea would be restricting irrigation- if the water is restricted around the time when the grape skins change colour (veraison) then the vines are stressed and their metabolism switches from leaf growth to maturing the fruit which results in less photosynthesis (remember that from the leaving cert?) and therefore lower sugar accumulation in the grapes. Chemical Sprays- not really proven or anything, in fact biodynamic growers say the sprays it actually increases the sugar levels…. of course the counter argument to this is that…. well before biodynamic farmers came along spraying was much more prominent in the past when alcohol levels were generally lower… Nighttime picking- One for the Biodynamic heads out there! The thinking is that grapes take up water overnight and may also collect some dew which dilutes the sugar levels.
In the Winery: obviously there are certain things the wine maker can do after the grapes have picked to reduce those alcohol levels. One big one is to do with the yeasts which ferment with the sugar. A lot of work is underway, Australia especially, with finding what yeasts will be less efficient at converting sugar to alcohol. Generally it si found that one of the best is actually wild yeast that will grow in the Vineyards. Also because of this the grapes are picked at lower sugar levels because they want to avoid the fermentation getting stuck because wild yeast will not multiply as quickly. Another method is to use open-top fermenters. This is where an open-top fermenter will allow some of the alcohol to be driven off. If this is combined with a warm maceration (basically when all the good stuff is separated from the bad stuff…) between 1 and 1.5% can be taken out of the alcohol. Adding water- pretty self-explanatory. Its legal in California (within limits) but illegal in most other places… obvious bad points of this- it ruins the wine if its done too much! It’s not Mi-Wadi!
Anyways there we go some of the techniques used for lowering alcohol levels in wine. A bit of a sciencey blog today, you can tell by the serious lack of exclamation points I used!!!!! So there you have it- hopefully ye found it interesting!