The world of Brewer's Yeast

Probably the most amazing step in beer production is the process of fermentation. It is magical how a small organism, a fungus, can transform unpalatable, sweet wort into the most fantastic beverage we know as beer. In the beginning, brewers had no idea what yeast was, or that it was responsible for the transformation. It wasn’t until 1857 that French microbiologist Louis Pasteur proved in the paper “Memoire su la fermentation alcoolique” that alcoholic fermentation was conducted by living yeast.
Simply, brewer’s yeast consumes the carbohydrates (sugar) in wort producing alcohol and carbon dioxide. Not so simply, yeast is responsible for many flavors, aromas, esters, acids, phenols, mouth feel, and more. Is yeast the most important ingredient in beer? Well, without it there is not beer. However, I feel it is also the most important variable ingredient, a powerful tool in creating specific styles and variations in a craft brewery.
Typically, a brewery uses on house yeast, and rarely another one for special brews. Our brewery has always juggled many yeast strains. Currently, we our fermenting with: California Ale, Irish Ale, French Saison, Belgian Trappist, two Brettanomyces, and two bacteria (I will explain Brettanomyces bacteria in a future post) in our cellar. We are fortunate to have three professional yeast laboratories at our disposal that bank hundreds of yeast strains. We use the California Ale yeast for our standard beer production: very clean fermenting work horse yeast. We are not looking for aroma or flavor contribution, rather the process of turning wort to beer. On the other end of the spectrum, our Saison yeast provides amazing notes of Pepper, earth, and spice. This contribution of character is so important that you cannot brew (in my opinion) Saison style ale without it.
We love using different yeast so much that we fabricated a yeast brink. The photo shows our unique system (we do not have a name for her yet). We are able to grow and clean different yeast strains. A stainless steel mixer is attached and a glycol jacket allows us to cool the yeast for storage. Sanitary ports at the top and bottom allow us to move the yeast in a closed environment. This is prototype #1, we will make a couple adjustments for #2, and eventually have a few of these in our cellar program.
And now, as I love to do for my own fun, is a count of all the different yeast strains and bacteria we have used in our brewery: California Ale, English Ale, Irish Ale, London Ale, Scottish Ale, Trappist super high gravity, Belgian Golden, Kolsh, Hefeweizen, Hefeweizen IV, Weinenstephan Weizen, Belgian Wit, Belgian Wit II, Trappist, Bastonge Belgian, Belgian Saison, German Lager, Dutch Castle, French Farmhouse, Brettanomyces Clausscenii & Lambicus, Lactobacillus, Pedioccocos.

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