In the beginning there was yeast.  Then came *hic* alcohol!  Well, that may oversimplify things just a bit.  The actual origins of fermentation go back roughly 5000 years to ancient Egypt, when it is said that some grain was left outside in the rain accidentally (and ingeniously, I might add).  The resulting fermentation had some awfully interesting results.  So, alcohol's roots are not exactly movie-worthy, but the progression to today's refined alcohol- be it beer, wine, mead, whisky, rum, vodka, etc.- are much more interesting.  But, you are not here to learn about ancient Egypt, are you?  So, lets get to it...

Yeast is a single-celled organism that, for our purposes, consumes sugar in an aqueous solution and converts it into alcohol (ethanol, to be precise).  It is somewhat more complex than this, which we shall explain shortly, but the important fact here is that sugar + water + yeast = alcohol.  Knowing this basic fact, we can now look at the life-cycle of the yeast cell and how to get what we want from it.

While yeast is a simple organism, it still has nutritional requirements if it is going to perform.  Just like you and I require nutrition to go about our daily tasks, yeast does, too.  Yes, yeast has a much less complex nutritional requirement than we do, but it still requires adequate nutrition in order to do its job.  If you add yeast to a simple sugar and water solution, you can sit back, relax, and watch the yeast do nothing.  It is really not all that exciting to watch.  Add the proper nutrients, vitamins, and minerals to that same mixture, however, and you will see the yeast come to life and happily consume all of the sugar, replacing it with alcohol.  With that said there is another important factor that we need to consider- oxygen.  Yeast will convert the sugar into alcohol providing it is starved of oxygen.  In the presence of oxygen, yeast will bud and reproduce, making more yeast cells.  This is actually a very useful piece of information, as it allows you to control what the yeast is going to do once you combine it with your nutrient rich sugar solution.  If you do not pitch (toss in) enough yeast to do the job, then it will be very sluggish.  The yeast needs more friends and family to help out.  By stirring the mixture vigorously, we can generally drive enough oxygen into the liquid to give the yeast the opportunity to use some of that sugar to multiply.  The yeast will also consume the oxygen while it multiplies, and when the oxygen is exhausted, the yeast will get to work converting your sugar into alcohol.  The time during which the yeast is multiplying is known as a 'lag phase'.  You will generally little visible action during this time, and it can range from less than an hour to a day or more.  In fact, if you continue to drive oxygen into your mixture for the entire process, you can make yourself a nice big bucket of yeast.

Now, with that said it does get a little bit more complex.  Different strains of yeast have different nutritional requirements.  Without proper nutrition, that is, the correct balance of the different minerals, nutrients, and vitamins, the yeast will not perform to the best of its ability.  Lack of proper nutrition will cause stress on the yeast.  And, stressed yeast will produce byproducts which result in not only a foul smelling and tasting product, but for every bit of sugar that the yeast converts into byproducts there is less sugar remaining to convert into alcohol.  Therefore it is in our own best interest to go the extra mile in order to keep our little yeast friends happy, and they will make us happier in return.  Remember, lack of nutrition is only one potential stress on your yeast.  You will also want to always maintain a watchful eye over your fermentation temperature to ensure that it remains within the 'happy zone' for your particular yeast.

Another stress on the yeast that is often overlooked is the optimal maximum alcohol tolerance of the yeast, which can be further divided into two sections- before and after.  In the before zone we have to consider the stress created as you increase the sugar content in your mixture (also called a 'wash').  The greater the concentration of sugar, the greater the stress on the yeast cells.  It is actually possible to increase the sugar content to the point where the yeast simply cannot ferment it.  Even as you near this maximum sugar concentration you will create an ever increasing stress on the yeast.  This stress will increase the production of byproducts during fermentation.  The 'after' stress is the percentage of alcohol that you are requesting of the yeast.  Each strain of yeast has a limit on the percentage of alcohol that it can survive in.  And, yeast is not 'born' with this tolerance, meaning you cannot put yeast with a tolerance to 18% alcohol into a mixture with 15% alcohol and expect it to perform.  This sudden immersion into the alcoholic mixture will kill the yeast.  When we refer to a yeasts' alcohol tolerance, we are actually referring to the percentage of alcohol that it can build its tolerance to.  Sound confusing?  It is actually very simple.  As yeast converts more and more sugar into alcohol, and the percentage alcohol in the wash rises, so does the yeasts' tolerance to alcohol.  It will hit a certain point, however, where the poor little yeast can take no more, and will cough, sputter, and die.  You can actually hear it begging for its life (well, not really, but if you have indulged a bit too much you may at least hear the coughing and sputtering).  I guess you could say that yeast is almost like a guppy; it will eat and eat until it literally dies of its own over-indulgence.  So, it is important to know the maximum alcohol tolerance of the particular yeast strain and stay a little bit below this in order to avoid added stress.

Combined Stress...  So, you know the optimal temperature range of the yeast strain, and its alcohol tolerance.  What if you near the limits on just one of those?  The yeasts' tolerance for the other is reduced.  For example, if you get very near the top end of the yeasts' temperature limit, it will not be able to squeeze out quite as much alcohol.  The combined stress will be too much, and it will die out before achieving its normal maximum alcohol potential.  So, it is best to avoid pushing the extremes of the yeast without knowing exactly what you are doing, and just what the repercussions will be.

So, how do you know the optimal nutrition for a given yeast strain?  If you have a laboratory and a degree in fermentology, then it is really quite simple.  And, if you don't have a degree and an in-house lab, well, you might as well give up now.  Hmmmm, maybe I was a bit hasty.  There just may be another way.  Choosing the correct yeast for your application may not be so difficult, after all.  There are some very good pre-packaged yeasts available that combine specific yeast strains with an optimal mix of nutrients, minerals and vitamins, based on the proposed use of the yeast.  This allows you to simply decide what you intend to produce, and select a yeast accordingly.

Sugar Fermentation
The simplest wash of all is a basic combination of sugar and water.  Unfortunately, sugar offers absolutely no nutrition for the yeast, so if you toss in a basic yeast- even one sold to you as a "distiller's yeast", then nothing will happen.  What is being sold through various home brewing and home distilling companies as "distiller's yeast" is nothing more than a high-alcohol tolerant strain of yeast.  That is not to say that it does not have its place, but having read the preceding information you already know that yeast needs nutrition, so this yeast on its own cannot perform.  A well known brand of such yeast is SuperStart by Lallemand.  Unfortunately, this yeast is generally sold in 1lb containers, making is less than optimal for long-term use after opening, due to the tremendous increase in speed at which the yeast cells will die after the package is opened and the yeast comes into contact with the humid air.  There is a reason that wine, beer, and high-alcohol yeasts are nitrogen packed!

So you have this high-alcohol yeast, packed in just the right size package for your needs- how do you know what nutrients, minerals, and vitamins to add?  You don't.  However, if you have been talked into purchasing such a yeast, there is a generic product known as "distiller's nutrients' that was developed with a cooperative effort between Brewhaus Inc. in the USA and Gert Strand AB of Sweden.  The product is a standardized mixture of more than 20 nutrients, vitamins, and minerals that most high-alcohol yeast strains require.  While it is not optimized for any given yeast strain, and therefore will result in a higher than normal production of byproducts, it does give a relatively clean fermentation, and given that the alternative is throwing away the yeast (a waste of money), then it suddenly becomes a darn good idea.

So, you don't have the laboratory or degree, and have not been duped into purchasing yeast with the expectation that it will 'be all that it can be'.  Where do you go from here?  Fortunately for you, in the 1980's a company in Sweden that worked with many small distilleries saw this very issue and came up with a solution.  They compiled the right mix of nutrients, minerals, and vitamins for a yeast strain, and packaged it all together in a single-use size.  Given virtually perfect nutrition the yeast worked so quickly that it was dubbed Turbo Yeast.  Since then several other producers have copied this concept, some more impressively than others.  To ensure that you are using the best Turbo Yeast possible, it is best to stick to brand name yeasts such as Brewhaus, Alcotec, and Prestige.  Doing so can help avoid ruined batches, uncompleted fermentations, or elevated byproduct production.

Non-sugar Fermentation
We already know that yeast ferments sugar, only sugar, and nothing but sugar (so help it... well, you get the idea).  So, what is this talk about non-sugar fermentation?  It can't be!  Tell me it isn't so!!  Relax.  You have not wasted the last 20 minutes reading everything that got you here.  By non-sugar fermentation we are simply referring to the fact that we are not just dissolving basic sugar in water and tossing in our beloved Turbo Yeast.  No, we are actually going to have to work for the sugar now.

Sugars are quite simply a short-chained component in things much larger, such as starch.  Yes, you heard right, and no, that does not mean that you can steal your wife's laundry starch and turn it into booze.  Starch, such as those found in abundance in potatoes, corn, barley, and a host of other foods, are an excellent source of fermentable sugar, if you are willing to go get 'em.  These starches are simply long-chained sugars.  And, yeast is too lazy to efficiently ferment starch, so you have to do part of the work for it.  Without getting into extensive detail (which could cause me to ramble even more, leading into an instructional book the size of War and Peace (with the Peace coming from the alcohol that you have so painstakingly produced)), you require enzymes to act as a hatchet, chopping the long chains into short ones.  Well, that sounds simple enough, now give me a potato and some enzymes.  Don't we all wish it were that easy?

Coming: Basic sugar wash instructions

Coming: Basic mash instructions

Coming: To test, use hydrometer.  Pull instructions from BH site.