ferment

Making Simple Fermented Beverages

Copyright 1993 by E. Chris Garrison (chris@homebrew.net)

Contents:

Introduction

This is meant to be a simple guide to basic fermentation procedures, and is not meant to be a comprehensive manual. Most is based on personal experience making meads, wines, and ciders. The intent is to use as little special equipment or ingredients as possible, using whenever possible those things easily obtainable at a grocery store or hardware store. Some recommendations are made for things that may be bought at a beer or wine making supply store, but all of these suggestions are optional.

Equipment

  • Some kind of seal-able container
    • 1/2 or 1 gal glass jug
    • plastic pickle bucket with hole in lid for cork
    • plastic 2-liter pop bottle
    • glass or plastic carboy (several gallon jug)
  • Fermentation lock
  • Size 8 stopper (for 1/2 or 1 gal jugs)
  • Siphon tubing (clear vinyl tubing (1/2 inch dia) from a hardware store)

Possible Ingredients

  • Honey
  • Sugar (sucrose)
  • Corn Syrup (glucose) (watch out, most commercial corn syrup has vanilla added)
  • Corn Sugar (dextrose)
  • Fruit (dried or fresh)
  • Fruit Juices (can be concentrate, but no preservatives, watch out for Potassium Sorbate, it is often mentioned in small print even in “100% juice”)
  • Molasses
  • Maple syrup
  • Acids
    • Acid blend (tartaric and malic usually)
    • Ascorbic (Vitamin C, can use lemon, orange juice, acts as an antioxidant as well)
    • Citric (found in citrus fruits with Ascorbic)
    • Tannin (can use tea or raisins)
  • Yeast Nutrient (in theory, can boil yeast from previous batch for this, but commercial seems to work best)
  • Spices (cinnamon, cloves, ginger, etc)
  • Pectic Enzyme (optional unless you use fresh fruit pulp, though some fruit juices (pear and apple notably) require this to clear)

On Fermentation and Yeast

Yeast is essential to all alcoholic beverages. It is a living thing, trillions of cells in your fermentation vessel, all hungrily turning sugars into carbon dioxide and alcohol for you.

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.

On Sanitization

Yeast is tough and tends to beat out most competitors because of its ability to live in a solution of alcohol, where bacteria and fungus tend to die even at low alcoholic percentages (though some can live almost as well). It also survives well because of its rapid reproduction rate as compared to other micro flora and fauna. However, survival isn’t everything, since even a small infection can spoil the odor and flavor of your beverage. You can’t get sick from these infections, since anything bad will SMELL too bad, and taste worse.

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!

Procedure

  • Prepare the yeast. You can either start from a package of yeast or from the leftover yeast from a previous batch. If you’re using a package of yeast, it can just be thrown in the must, but works better if you re-hydrate it in a (sanitized) glass of water, covered with a plate or plastic wrap. You can also give it something to do by tossing in a spoon of sugar or by substituting some fruit juice for water, but this is not necessary. Re-hydrating only takes about 15 minutes.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). 
  • Prepare your must. (the must (or wort, if you are a brewer) is the unfermented mixture of sugars and acids and juices and nutrients). There are different schools of thought on how this should be done, whether you need to boil honey solutions, or even juices. You really don’t have to boil at all. It helps to fend off infections and blend ingredients, but tends to change the character of whatever you’re preparing, and sometimes this can produce less desirable results. Personally, I like to heat honey solutions to almost boiling, but I don’t boil (or even heat) fruit juices. I do like to pour boiling water over pieces of fruit to get wild yeast and bacteria off of the surface of the fruit. This also makes the fruit easier to crush and extract juices.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.

     

  • Add the yeast to the must. Be sure to leave “head space” at the top. If you are fermenting a gallon jug of apple cider, pour off about two cups of the juice and save it for later. (Add this back in after you lose volume to racking). If you don’t leave space at the top, the foam that results from the vigorous initial fermentation will blow out of your fermentation lock making a terrible mess!
  • Put on the fermentation lock. (in a pinch, rubber-banding plastic wrap over a lid will work, though it is harder to tell how the fermentation is progressing without the satisfying bubbling of a lock)
  • Wait. The fermentation will start within a day for ale or lager yeasts, within two for all others. Fermentations that are started off of cultured yeasts start slower than from a package of yeast, due to lower initial population, but will get going just as fast later. Fermentation obviously takes longer for higher alcohol percentages, but it is not a linear relationship. As initial sugar concentration increases, the time to ferment goes up much faster. Beer strength beverages (about 5%) can take as little as a week or two, while heavy meads can take a couple of months. Most wine-strength (10-12%) beverages take about a month or so.
  • Racking. After the initial burst of fermenting, some yeast will fall out of solution and form a thick layer on the bottom of the fermentation vessel. If the must is left on top of this, a process called autolysis may set in. When yeast begins to have to compete for sugars more, sometimes they’ll turn to dead yeast for food, which produces a sulphury smell like rotten eggs. To avoid this, it is desirable to siphon off the liquid, leaving the sludge (“trub”) behind. This is known as racking. The first racking is the most important, though you should rack whenever a fairly thick layer accumulates (though not more often than once every couple weeks, or you’ll lose too much liquid). You can add more juice or honey or sugar when you rack to revive the fermentation if you like, but toward the end you probably shouldn’t if you want it to clear more quickly.
  • Clearing. After the fermentation stops, the yeast will start falling out of solution. If, after some time after it has stopped, it still isn’t clear, you could have fruit pectin or by-products of fermentation still in solution. This can be prevented by adding pectic enzyme anytime in the process (see the bottle for amounts). Also, a clearing agent like bentonite (a kind of clay) or gelatine can be used to clear it. If you don’t mind it being cloudy, don’t worry about it.
  • Bottling. This can be as simple as siphoning into a sanitized and rinsed plastic pop bottle or as complicated as using wine bottles and forcing corks in with a bottle corker. You can use half gallon glass juice bottles quite well too.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.
  • Aging. None of these have to be aged in theory, though the quality improves a lot with age. Carbonation takes about a week to two weeks. It is usually best to wait at least a month on anything, and the longer you wait, the better it will be. Most references say wait at least six months or a year, especially for pure meads, but I’ve found things to be drinkable earlier. Keep the bottles in a cool place out of direct sunlight. Things age better if not jarred or disturbed as well. You can age things in the fermenting vessel as well, but bottle aging seems to work best for me.
  • Drinking! Ah, this is what it’s all about, the end product!
Advertisements