Alcohol %age

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deesloop

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Hey all.

So alcohol is produced by the yeasts conversion of sugars.
Is it true than the more sugar you add the more alcohol can be produced - assuming the yeast is hardy enough?

Lots of yeasts I see are advertised as being capable of handling up to 18% which is fine for wine,
so can I simply add more sugar to a wine that previously yielded 12% in order to make stronger wine?

And, how do they make spirits with 40% ABV? This site sells whisky yeast but is only certified to 15%? How can that be?
Who would ever drink 15% whisky? My whisky club friends would show me the door is mentionedd rinking something like that!

Plus I have bottles of cask strength (you USA types call it Barrel proof) whisky hitting 62% what do they use, and could you use those in wine?

Thanks
 
Your first principle that more sugar will produce more alcohol is correct to the point (as you know) the yeast can’t handle any more. To.a degree you can add more sugar to bump a 12% wine kit or recipe higher though once you get to 1.100 specific gravity, I’ve found the 18% tolerant yeast to refuse to begin fermentation. The best method increase the alcohol to 18% is step feeding. That involves adding sugar in increments during primary fermentation.

Sprits begin as fermented grains but go through the heating and cooling process that creates a vapor and concentrates the liquid. For a better understanding you need to watch YOUTUBE or visit a whisky distillery. We aren’t supposed to talk about spirits on this forum.

Fortified wine involves adding a spirt (usually brandy) to a wine either during primary fermentation to stop active fermentation and retain some residual sugar or after primary fermentation.
 
Thanks for the info, while it was more a question about the resiliency of yeast, my apologies for straying into the spirit realm.
 
it was more a question about the resiliency of yeast
If unfed, yeast will die, roughly around the 9-12 month mark.

If your question is regarding restarting a commercial wine, the answer is no. You'd need to add fresh yeast, and I don't recommend trying it as the results are hard to predict. If you want a stronger wine, buy a stronger wine.

Regarding homemade wine? It depends on how long since the fermentation ended. The longer the period, the less likely a renewed fermentation is likely to happen. Please note this is regarding an intentional refermentation. If you don't want the ferment to restart, there is a corollary to Murphy's Law that says it will. ;)

The yeast used makes a huge difference, although the published tolerance level is an average measured in a laboratory. The actual tolerance of the yeast may vary, e.g., a yeast stated to handle 16% ABV may actually handle 15% or 17%. It's a living creature and it varies.

The ABV also makes a difference -- the higher the ABV, the more difficult it is to get a renewed fermentation. Step feeding small amounts of sugar is often necessary.
 
This site is for winemakers and beer brewers. As a reminder, and if you did not realize, distillation of any kind is illegal in the USA. This is true even if you are producing distilled spirits for your own personal use.

There are other sites that are dedicated to distillation, but we like to stay away from that subject.

Since the underlying theme of this thread is the tolerances of yeast, I will not remove it, but please keep what I have said in mind.
 
Actually didnt know it was illegal and it may well be the same in the UK, I dunno.
Apologies for straying into the gray areas, no offense intended
I now understand the difference between fermentation and distillation.
Distillation is like concentrating the alcohol so yeast doesnt actually work up to 50%.

I'm not really looking to create high alcohol wine its juse the kits and the from fruits I have produceahve been 9% tops - which is OK for a white but not so for a red (IMHO), should be 12% if not 14-15%.

Will read some more but thanks for responding.
 
Distillation is like concentrating the alcohol so yeast doesnt actually work up to 50%.
In general, wine yeast strains all reach their max alcohol tolerance at 18% ABV or lower, although @salcoco recently said he step fed EC-1118 up to 21%.

In general, yeast is yeast -- it eats sugar and emits alcohol and CO2. "Wine yeast" are strains that provide the most benefit to humans when fermenting grapes into wine. "Beer yeast" are the same, except it works best for roasted barley (and similar grains). "Bread yeast" are ... you get the picture. I'm sure there are thousands of strains for which we (humans) have no practical use.

"Wild yeast" is whatever happens to grow on the grape skin or is in the air. There are thousands of strains of yeast, so it's luck of the draw. Although, the most successful wineries of Europe probably got lucky in having a good strain prove dominant in their vineyards. This is a very extensive topic, although the short answer for home winemakers is to consult a yeast chart that lists the characteristics of various commercial wine yeast and picking the one that fits your needs.
 

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