Capn Jimbo's Rum Project Forum

[Capn Jimbo]

To O2 or not to O2... that is the question!


In the last section you learned that the early yeast forms propagated by using oxygen to turn sugars into alcohol, carbon dioxide and water (releasing needed energy), and later without oxygen by turning alcohol back into aldehydes.

Aerobic or anaerobic. But here's the deal...

It turns out that there are millions of different kinds of yeast, but we know about only 250 of them can than pull off this trick - and of these only 24 are good in the sense that what they ferment is palatable or tastes good to us humanoids.

It was not long before humans discovered how to use these "good" yeasts to provide tasty, sweet and slightly alcoholic drinks. They discovered that the fermentation had to be stopped before too much alcohol was created, because then the yeasts would then convert the alcohol back into nasty aldehydes.

With regard to grains they learned that left to their own, the budding grains would use the "sweet" (as they called it), leaving little for the yeast to turn into desired alcohol. They learned that by stopping the budding early (by heating), this would leave the sugar for the alcohol producing yeasts.

The early Lambic brewers and distillers simply depended on wild yeasts, especially those that lived on the grain or fruit. They'd simply leave the crushed fruits, malted barley et al uncovered and let nature take its course - but often this method failed when undesirable wild yeasts gained access and spoiled the outcome.

It was then they discovered that recycling the "dregs" from the last good batch gave the good yeasts a headstart, enough to dominate the proceedings and ensure yet another tasty brew. In fact our word "yeast" comes from "doerst", which evolved from "dros" (dregs). The Norwegian word for yeast, "kveik" evolves from the word for "kindling", used to "restart the fire".

Compare to the Jamaican use of "dunder" - the leftovers from a previous distillation to "kickstart" the new fermentation and maintain the line.

Neat, eh! Still, these early brewers really had no idea of what yeast really was, or how it worked. They simply knew that something good happened, and they learned how to make it happen.


The mystery ends!

Understanding and discovering "yeast" didn't happen until really quite recently, in about 1830.

German Theodore Schwann was the first to discover that yeast was in fact a living organism in 1837. Another German, Julius Meyen, finally named it - Saccharomyces, the common name we now all know, or should...
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[Uisge]

Like the use of "dunder", the sour-mash method of producing bourbon is the same thing, recycling a portion of the distillate for the next batch.

Pizza dough maker do the same thing, where there is a "mother dough" that is massaged into the fresh dough.

Yeah, I know trivia


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Capn's Log: Not at all, good points. Dunder just adds the element of time, allowing the dunder to putrefy in the dunder pits (aka mock pits) - it's really quite rank. Dave Broom relates a Jamaican distiller who claimed he hadn't seen the bottom of his dunder pit for thirty years!

The key is the natural bacteria. The Home Distillers group has experimented with dunder (here).