The process of fermenting is basically feeding sugars and nutrients in solution to yeast, which return the favor by producing carbon dioxide gas and alcohol. This process goes on until either all the sugar is gone or the yeast can no longer tolerate the alcoholic percentage of the beverage. Different yeasts produce different results, and have different tolerance levels. Here is a table of yeast tolerances:
Yeast type Approx max alcoholic % Ideal temp range -------------------------------------------------------------------- Ale 9% * 60-80 Lager 9% * 45-55 ** Bread/baking *** 12% 60-80 Wine 14% 55-75 Champagne 20% 55-75 * Can go higher with time, but slows down greatly at this point. ** Can ferment at ale temps, but tends to leave cloudy results. *** baking yeast can be used in a pinch, and in fact works well with citrus wines, but can leave a bread-like smell and taste in the beverage that some find objectionable.Yeast can't live on sugar alone. It is happiest when it has a real organic soup of acids and nutrients and minerals, like any other living thing. Yeast actually does "best" in an aerobic (oxygenated) environment, but then won't produce alcohol, just CO2. Bacteria also like oxygen, so while it is good to agitate the solution before yeast gets added so the yeast can be fruitful and multiply, it is best to keep as little oxygen from getting to your beverage after fermentation has started.
Honey has a lot of what yeast needs, but is somewhat resistant to being fermented by itself. A pure honey solution will ferment, but it can take three months to a year to ferment. Yeast nutrient and some sort of acid added will speed this up greatly, taking more like a month to ferment, depending on the concentration of honey in solution.
Fruit juices often have all that yeast needs all by themselves. Notably grape juice is a favorite, as it has the acids and tannins and sugars needed. Apple juice stands on its own quite well too. Other juices may need acids (not just for the yeast, but for flavor!), and many commonly need tannins to be added. Watch out when using rasins for tannin, they'll add sugar and color to your beverage, so they might throw off your sugar/volume estimates. Also, I gather that the color change is not that positive.
Yeast is very hardy and will get by with most anything but plain white sugar (though sugar can be added to honey or fruit juice to increase the alcohol yield). It will even ferment white sugar with the right acid and nutrient blend, but this is difficult to do.
To avoid this, keep everything that comes in contact with your beverage very clean. This is especially critical when cleaning the fermenting vessel. You don't need to sterilize, as it would be impossible to keep things sterile anyway. A solution of bleach water (one capful for five gallons will do nicely) will kill most anything. You'll need to be very sure all the bleach gets rinsed off, though, since yeast will have trouble living in the presence of chlorine. Also, even the tiniest amount of bleach can produce awful flavors and odors when it reacts with other things in your must.
If something has just been in use and you're rinsing it out to put more stuff in immediately, scalding hot water out of the tap will do nicely, no need to break out the bleach!
Culturing yeast is the process of taking yeast from the bottom of another batch's fermentor or by taking a bit of a another batch and adding it to a small amount of sugary solution to grow enough yeast to start another batch. This is a handy way to stop buying yeast, but is a bit riskier, since you risk infection from the less vigorous start. You just have to be a lot more careful with sanitizing equipment.
Culturing takes a few hours, but is best done overnight. Be sure the culturing container is sealed against the air (plastic wrap and a rubber band over the top of a glass is fine, or you can get a fermentation lock and stopper that fits a bottle).
A solution of a little less than two pounds of honey per gallon will ferment out to about 10-11% alcohol, which is wine strength.
Most fruit juices, especially apple and grape, will ferment out to 7 or 8 percent, possibly up to 11 percent. Adding a half pound of honey per gallon will make a more potent wine or cider.
Mix juices, honey, tannins, acids, nutrients in fermenting vessel.
If you want your beverage to be carbonated, that's another matter entirely. Don't use the juice bottles, but the plastic pop bottles work very well at holding pressure. If you use something that is not designed to hold pressure, like a wine bottle or a juice bottle or jug, you will have grenades when the pressure gets high enough.
To carbonate, add a small amount of sugar or juice (a half cup of white sugar to five gallons) to the beverage *before* putting it in bottles. This won't work if you are already at the limits for the type of yeast you're using, however.