This blog provides information for educational purposes only. Read our complete summary for more info.
Distillers Yeast Review
We get a lot of questions about yeast. Folks want to know "which yeasts are the best" for making high quality whiskey and other spirits.
Admittedly, our experience with distillers yeasts is somewhat limited. We found a yeast we liked using a while back and stuck with it. We hadn't really done much side by side experimentation with other yeasts...until recently. We decided to test the 4 most common yeasts used by home distillers (with the exception of a wine yeast) and pitted them head to head against one another. Here's how we did it.
We made a 2 gallon batch of rum mash using 3 pounds of pure cane sugar and 2 pints of unsulfured molasses (with a potential alcohol of 12.9%). We then split the mash into 4 glass carboy's and added a different yeast to each container.
We tested bread yeast, champagne yeast, super start distillers yeast, and Turbo Yeast.
We let the batches ferment for almost 3 weeks (to make sure we had maxed out the potential of each yeast), then we conducted a taste test. We were never able to actually distill the batches of wash because mother nature just wouldn't cooperate with us (it was too damn cold outside).
Our assumption was that the bread yeast had not met its alcohol potential and would be sweeter than the rest of the samples due to excess sugar. We also assumed that the turbo yeast might taste and smell a bit funky, because that's what a lot of people report about it. We also have some experience with turbo's ourselves and have noted these characteristics. We thought the champagne yeast would be dry, and weren't sure how the super start would taste among the rest of the samples. We hadn't taken a final specific gravity reading before the taste test, so the alcohol content of the samples was not known to us as we were sampling them.
As it turns out, our assumptions were dead on, with one surprising exception. Here's what we noted:
We tested Liquor Quick's Turbo Pure X-Press (dehydrated), which is rated to produce up to 18% alcohol. According to the manufacturer, this yeast was created to produce "a very clean wash with minimal congeners." We disagree with the first part of that statement.
The wash was anything but clean. It smelled and tasted absolutely awful, most likely due to excess nutrients that weren't used by the yeast. In defense of Liquor Quick, perhaps if we had added more sugar and the yeast were able to work longer (using more of the nutrients) the wash would not have tasted so bad.
We actually agree with the second part of the above mentioned statement. The wash contained very few congeners. Congeners is a fancy term for all of the tasty ingredients found in the mash. The more congeners, the more mash flavor, the less congeners, the more devoid of taste the wash and final product will have. There was hardly any trace of the cane and molasses flavors. However, remnants of the nutrients were still very present and the wash tasted and smelled terrible.
In summary, we don't recommend turbo yeast for making high quality spirits. If you're making gas for your lawnmower, turbo will work just fine. Otherwise, we recommend you avoid it at all costs.
We tested Red Star's Pasteur Champagne Yeast (dehydrated). The champagne wash sample was extremely dry. Molasses and cane flavors from the wash were almost completely gone. A very slight bitter taste from the molasses was all that remained, which is definitely not the best part of the molasses flavor. The yeast itself also imparted little to no flavor to the wash, making this sample extremely clean. If one is striving to make a neutral grain spirit, such as vodka, we think champage yeast would work very well. However, it is now apparent to us that this yeast is not appropriate for flavorful spirits such as corn whiskey, full bodied, authentic rums, etc..
Super Start Distillers Yeast
We tested Crosby & Baker's Super Start Distillers Yeast, now known simply as Distillers Yeast (UPC: CB 9904A*). This stuff is available by the pound and is given no description by the maker. Over the years this is the yeast we've become accustomed to using, partly because it's sold by the pound (and It takes a long time to use an entire pound of yeast) and partly because we experienced what we felt were good results. Our assumption was that this yeast was going to blow the competition away. However, we were wrong.
The Super Start wash tasted almost exactly like the champagne yeast wash. They were actually a bit difficult to tell apart. The only difference was that the champagne yeast had a slightly cleaner taste and smell. Yeasty smells and flavors were a bit more prevalent in the SS sample. In our opinion, because these samples didn't taste anything like cane or molasses, these yeasts are probably better suited for making high alcohol, neutral grain spirits than they are for making sippin' whiskeys. Because the champagne yeast had a cleaner taste than the Super Start, we'd venture to say that it'd be the better choice between the two.
The performance of Super Start in this experiment is actually good and bad news to us. It's bad news because we have a lot of Super Start on hand. It's good news because we're always looking for ways to make better whiskey, and moving away from SS is an obvious change we need to make. Accordingly, due to the results of this experiment, we now no longer exclusively recommend Super Start as our yeast of choice. We're currently planning our next yeast experiment and will re-test champagne, super start, and a few other high alcohol yeasts to determine which we think is the best for making high alcohol, neutral grain spirits.
The surprise of the day was bread yest. We tested Fleischmann's Active Dry Yeast. Our initial assumption was correct: the bread yeast tasted slightly sweeter than the others. Much more of the cane sugar and molasses flavors were present. Overall, this was actually the best tasting wash, which we kind of half expected. We assumed that the bread yeast sample tasted better because the yeast had hardly done anything and hadn't produced much alcohol. However, we were dead wrong.
The ABV of this sample was on par with the rest of the samples (see below). This means that bread yeast had managed to produce as much alcohol as the rest of the yeasts, but had done so without stripping out as much of the natural mash flavors. This wash tasted great and we see no reason to recommend against using bread yeast for creating flavorful spirits. However, in our next experiment we're going to test bread yeast against other yeasts designed for crafting full bodied whiskeys.
We determined potential alcohol using a beer hydrometer. We also did some calculations by hand to back up hydrometer readings (and to prove how smart we are). Also, our brix refractometer was missing on test day, which is the other reason for the hand calculations.
Our beer hydrometer displayed a starting gravity of 1.10, corresponding to a potential alcohol of 13%. Between the molasses and the cane sugar, we ended up adding a total of 969 grams of sugar to a total of 3785 grams of water, for a brix of 25.6 and a potential alcohol of 12.8%. Because the result of both calculations is so close we're very confident that the potential alcohol was somewhere around 12.9%.
The final gravity measurements of wash samples were almost identical. The samples were all within a half percent of 12.5% starting alcohol, with champagne being slightly higher than the rest. In other words, each yeast essentially maxed out its alcohol production potential by eating more or less all of the sugar present in the wash.
These results convey absolutely nothing meaningful about the alcohol production potential of champagne, turbo yest, and Super Start yeast. It's obvious that these yeasts should be able to produce 12.5% ABV or higher. If we wanted to compare the alcohol yield potential of these yeasts we'd need to bump up the sugar content of the wash and give the yeast samples more to work with.
However, the experiment sheds some interesting light on the alcohol production potential of bread yest. We assumed that bread yeast would have stalled out well before consuming all of the sugar in the mash. We can now say with confidence that bread yeast (at least the brand we used) is able to produce 12.5% starting ABV, and maybe even higher. This is surprising news to us, as our previous (limited) experience with bread yeast suggested a much lower potential ABV.
Additional Yeast Resources
If you have not read our article "Making Moonshine - Fermentation and Yeast" check that out as we go into more detail about the fermentaiton process. We strongly suggest purchasing a copy of the book "Yeast" from Amazon.com. This books is 300 pages long and was written by professional brewers and scientists. It's an awesome resource on the topic of yeast. We've been reading this book and have learned a ton of stuff about yeast. Yeast is just as important as the other ingredients (corn, barley, sugar) in fine spirits, and without it, there'd be no spirits, as yeast is solely responsible for making alcohol during the fermentation process. Get this book if you want to improve the quality of your whiskey. Also, checkout our article "Bourbon, Whiskey, Vodka and Moonshine - How Much Yeast?" for more information on how much yeast to use on a batch of mash.