Why can't alcohol produced by fermentation be any greater than 15% concentrate?!
Why can't alcohol produced by fermentation be any greater than 15% concentrate?
Answers:
Dogfish Head World Wide Stout = 18% abv.
Dogfish Head Raisen De Etra = 23% abv.
Sam Adams Utopia = 24% abfv.
These beers achieved their alcohol levels through fermentation and not distillation.
presumably because the solution becomes toxic to the bacteria that are responsible for processing sugar into ethanol, killing them.
Above 15% the alcohol starts to kill the yeast that is causing the fermentation. Anything above 15% must be distilled to concentrate the alcohol. The distilation ends the fermentation process.
Too much alcohol kills the yeast, therefore the solution cannot continue to ferment. The tolerance of the yeast depends on the specific kind of yeast used in the process. Some types of yeast have a max tolerance of 5% alcohol, others can be upwards to 14-15%.
'Cause yeast dies around 15%
The alcohol kills the yeast.
It is just the bulk of the material can not sustain any more conversion from sugar and starch.
Distilation eliminates most of the excess water.
The alcohol starts to kill the fermentation process at about that strength, although I recall that 17% can be achieved at the cost of palatability.
it can, just not by yeast fermentation alone. the yeast cannot survive in an environment of over 15% alcohol. in fact, most yeast wont make it that far.
if you want to get the alcohol content over 15% you have to freeze ferment it. this technique was used in germany originally when beer drinkers wanted a stronger beer. its pretty simple. cool the beer to about 23 degrees and the water will freeze and separate out while the alcohol stays liquid.
by doing this, you can get much more alcohol by volume. however, the drinkability goes down significantly..
Even 15% is quite a high content if you're homebrewing wine or beer. If you want the most alcohol content possible, without distilling, follow these tips:
- Add plenty of sugar, and in stages, so it doesn't overload your yeast. Plus, more sugar = more alcohol, but this can also affect the taste.
- Add enough yeast - don't sprinkle it in. Follow the package instructions to get enough for whatever amount of wine you need. Make sure you use enough.
- use a wine, or better yet, champagne yeast from a brewing shop, not a baking yeast. They tolerate more alcohol.
- Activate the yeast properly. Normally, you can just let it sit in a cup of lukewarm water, and then stir it up after 10 mins or so, but follow the instructions on the package if tehre is some.
- Use a yeast nutrient/energizer if you can. Then help to create a suitable environment for the yeast to function.
- Allow your wine to fully ferment before siphoning/bottling/racking/fil... Let the bubbles almost stop completely before aging/bottling. That way, the wine is totally done fermenting, and the yesat has stopped and is done allowing alochol to be produced.
- Store your must/wine in a suitable environment: constant cool room temperature, meaning no drastic changes in temperature, and keep it somewhere dark.
But like I said, even following these tips, anything more than 15 or 16% will still be tough. If you're trying to make some kind of moonshine by distillation, that's another story. The more times you distill it, the stronger it gets.
A more practical option to make something like applejack is to freeze your wine/beer. It works well with cider. Put it in a bottle that won't explode or anything, and freeze the liquid until it's mostly solid, adn then filter out the solid, leaving just a liquid. Water freezes, which is what you are filtering out. THe alcohol will stay in liquid state. Basically you've gotten rid of excess water, and in creased the concentration of alochol in the remaining wine. Good luck!
Yeast cultures are not tolerant to high levels of alcohol. When it reaches this limit the yeast actually dies.To go further than 17% one uses pure alcohol and this is known as fortifying, as in Port Wine. Extreme caution should be taken in the type of alcoohl used and under no circumstance should industrial alcohol be used as it is toxic.