A question of yeast

[jkiiha]

Grain is often identified as the base of a great Bourbon's flavor. I wonder, however, to what degree the yeast used in the initial ferment plays in the process. As I've learned in my experiences as a homebrewer, the variety of brewer's yeast that one uses has a delicate, but very noticable effect on a beer's final flavor. Any thoughts on this? I would guess that the rather "rough" process of distillation kills many of the more subtle notes left behind in early fermentation, but this is all speculation on my part.

On an unrelated note, I would suggest that anyone interested in the process of making whisky learn how to make all grain beer at home. I have toured the distilleries before and after I became interested in brewing beer at home. Knowing a little more of the technical end of things really adds to one's appreciation of the difficulties in distilling Bourbon.

[cowdery]

Just as with brewers (maybe more so), bourbon distillers are very particular about their yeast. Some use "wild" yeast (practical distillers) while others use a pure strain yeast (scientific distillers). Jim Beam, for example, uses a yeast that Jim Beam himself bred on his back porch during the closing days of Prohibition. I think that "wild" yeast strain is responsible for some of the foxy flavor of Jim Beam white label.

The yeast's contribution to the taste of a bourbon seems best appreciated in a young whiskey. This is true of the grain qualities as well. As the whiskey matures, the influence of the wood takes over.

<A target="_blank" HREF=http://cowdery.home.netcom.com>--Chuck Cowdery</A>

[jkiiha]

Interesting. Belgian lambic brewers also use "wild" yeast to ferment their beers. They use open fermentation tanks to allow rain, dust and insects to fall into the fermenting wort. Although beer is made on a differing grain bill, the unique flavors of the yeast become very apparent when beers with relatively low hop schedules are compared. If you wish to see this effect for yourself, sample Chimay Ale against something like Bass Ale.

I am surprised, however, that the character of the yeast is able to survive distillation. Would it be safe to say that most of the loss is water?

Each area has its own microflora and microfauna that are unique in terms of their fermentation properties. I suppose that this makes Bourbon even more of a Kentucky product than I originally thought.

[Guest **DONOTDELETE**]

Yeast just doesn't get much 'air time' here on the forum or in 'the books'. The Regans have about a page. Waymack & Harris have about a paragraph. Jim Murrey mentions yeast in his section on mashing, but doesn't say much more than it's used in making distiller's beer. So really there is only scant mention of yeast as just another ingredient in the mash.

I spoke with Lincoln Henderson awhile back concerning Old Forester, and he mentioned that Brown-Forman had a full time micro-biologist to produce their yeast and to keep the strain pure.

From what little I think I know about it is that the yeast is very much a major player in the development of the character of the bourbon and that it is every bit as important as the mashbill.

I'd like to see an in depth article on yeast. OK everyone start researching and writing!

Linn Spencer

Have Shotglass. Will Travel.

[cowdery]

I may have misled you somewhat. A practical distiller will make a medium believed to be conducive to yeast growth, then allow a wild yeast to alight in that medium and begin to propagate. The distiller monitors its growth--how robust it is, how it smells, how the bubbles break, etc.--and may abandon it if he doesn't like the way it develops. If he likes it, he continues to propagate it and uses it to ferment his mash. Most traditional distillers use open fermenters so it's possible that other micro-organisms will get in, but that isn't necessarily encouraged. I guess I would say the yeast is wild, but may not quite as wild as what the Belgian brewers encourage.

As for the yeast character "surviving" distillation, since bourbon is distilled out at less than 80 percent alcohol, and in some cases as little as 55 percent, a lot of the character of the mash survives. That's the idea. It's what distinguishes whiskey from neutral spirits.

<A target="_blank" HREF=http://cowdery.home.netcom.com>--Chuck Cowdery</A>

[Blackkeno]

The Regan's book often includes information about the yeast strain and how long it has been in use--clearly implying its importance. I thought they mentioned that Maker's Mark had the only yeast strain that pre-dated the repeal of prohibition.

[Guest **DONOTDELETE**]

J.D. there is at least one person on this forum that has some real yeast knowledge, and that is Jim Butler. I was hoping that he would provide some input.

From what I have encountered in talking with various master distillers is that they are very proud of their yeast and that is about all that they will say. I do know that Brown-Forman has a full time micro-biologist that propagates their yeast and keeps the strain(s) pure.

Yeast is an integral flavor/character factor in any mashbill. The toughest part of acquiring real bourbonic knowledge is in the seperation of fact from fiction. There is just a whole lot hooey floating around out there masquerading as facts.

Linn Spencer

Have Shotglass. Will Travel.

[tdelling]

>Yeast is an integral flavor/character factor in any mashbill. The toughest part of

> acquiring real bourbonic knowledge is in the seperation of fact from fiction.

I certainly agree with that!

Interestingly enough, in talking to Fritz Mayrtag, I learned a few things concerning

yeast. Apparently a number of distilleries buy commercial yeast. He didn't

mention which distilleries, or what products (whiskey?, gin?, vodka?). I think

he said that some places use a mixture of home-grown and commercial, and

the home-grown is as much for showmanship as for taste. (Since a brewery

is one big yeast factory, Fritz has no need to buy yeast...)

Also intersting was that he mentioned the importance of bacteria. Sour mash

or not, you're going to have bacteria, and they're going to effect the taste.

Tim

[jbutler]

Linn is absolutely correct; there is much misinformation re: yeast and it cultivation in this industry.

I made a couple phone calls this morning to inquire about yeast maintenence. Specifically, those calls were placed to Drs. James Devay and E. E. Butler, both professors emeritus with the dept. of Plant Pathology, University of California at Davis.

Before one can assume the persistence and integrity of a particular strain of yeast, one must consider the methods employed to maintain the strain. In a hypothetical situation, say distillery X wants to maintain the particularly luscious and exclusive strain theyve stumbled upon. How do they go about it? The mash is subject to open air fermentation, which produces tremendous difficulty right off the bat, though this situation is probably dealt with by pitching enough starter into the mash to preclude the massive growth of airborne wild yeast strains.

Anyway, I digress. It's not enough to simply get hold of a few scoops of the bottom of the vat slurry and hope that youve maintained the culture for the next batch. The microbiologist at the distillery has an extremely difficult job. The microbiologist knows what his yeast looks like and how it behaves. He examines a culture under the microscope, selects cells which have similar appearance characteristics, propagates those cells, then has to test them to determine if the end product matches the desired flavor profile. That's a cursory examination, and I apologize in advance to anyone in the industry who feels their job has been grossly understated. I'm sure it's a very in-depth and detailed process, but not tremendously different from that which their counterparts at Parke-Davis have to undergo to ensure the integrity of their penicillium cultures.

The bottom line is that since yeasts are constantly mutating as a function of time, any given distillery has nearly zero chance of maintaining a particular strain. What they can do is maintain a performance profile. That is -- they know what they want, and can propagate yeast cells that get the job done, but the notion that somebody has the same bunch of yeast now that they had 80 years ago is fairly difficult to swallow.

Cheers,

Jim Butler

Straightbourbon.com

[Guest **DONOTDELETE**]

Thanks Jim! I'm going to find out just who that microbiologist is at Brown-Forman and give him a call. I'm sure that there are certain things that he just can't tell us and still keep his job, but there should be plenty of enlightenment available to make Bourbonia a better place to live.

Linn Spencer

Have Shotglass. Will Travel.

[ratcheer]

A little off-topic, but not much:

Years ago, I remember reading about one of the world's great beers, Pilsner Urqell from Chekoslovakia (I probably misspelled that). The article said that it is brewed with a yeast culture that has been maintained for over 1300 years! (I read it a long time ago - maybe it was since the 13th century, but I think the 1300 years figure is the correct one). It has been nurtured and protected throughout not a few wars and other upheavals.

It that is true, it amazes me.

[jbutler]

Pilsner Urquell ... now that's some good beer, one of my all time favorites.

Although it's sounds like the stuff of legend, it's hard to believe that a society that didnt know about the existence of micro-organisms until about 150 years ago could successfully maintain a yeast culture for more than a millenium. It's not so difficult for me to believe that they started with a batch of yeast 1300 years ago, and are still working with the descendants of those organisms; i just can't buy that the yeast cells they are using today resemble their antecedents in any way other than that they are yeast cells.

Cheers,

Jim Butler

Straightbourbon.com

[kitzg]

I suspect you are right -- but I, like you, love the beer -- especially when it is fresh in Europe.

Greg

[cowdery]

Sour mash is a big part of the equation, because it creates an environment friendly to the good yeast and hostile to outsiders.

But as for propagation of a particular strain, Jim hit the nail on the head. What a practical distiller cares about is performance, not the genetic purity of the strain. They judge this more with their noses than with their microscopes. That is why they keep the yeast going in multiple locations, so that if one batch "goes bad" (i.e., mutates into an unfavorable form), they can get some of the good stuff and pick up where they left off.

<A target="_blank" HREF=http://cowdery.home.netcom.com>--Chuck Cowdery</A>

[kitzg]

Based on those talks with Master Distillers I'd summarize that yeast can be just as important as the mashbill. And you're right about the 'hooey."

If you want to taste what difference in yeast, lower corn content, and mingling will do get to Kentucky or Indiana and try a bottle a top seller in Europe, Four Roses yellow label. Smoooooooooth.

Greg

[Guest **DONOTDELETE**]

OK Greg here we go!

This is a good example of how simular men with simular tastes like very different bourbons.Greg and myself are both devastatingly handsome middle aged men with beautiful blond wives. We both like bourbon. Here the simularity ends.

Greg loves wheaters, but I as rule do not. Greg likes Basil Hayden's, but I do not. Greg likes Four Roses yellow label 80 proof. I don't. Greg calls it smooooooth. I call it blaaaaaand. Tastes like a canadian blend to me. I bought a bottle once and will never buy another.

So who's right and who's wrong? We're both right! We find what suits our taste buds and drink it. We also say good things about the bourbons we like. We don't take personal umbrage if someone doesn't like what we like or think the way we think.

We do rag on each other from time to time, but all in good fun.

Linn Spencer

Have Shotglass. Will Travel.

[tdelling]

>Sour mash is a big part of the equation, because it creates an environment

> friendly to the good yeast and hostile to outsiders.

That's certainly true, but there are other ways of going about it than the

sour mash process. The idea is to merely lower the pH, which can be

done easily with a litle of your favorite acid (often citric acid). In order to

deflect criticism that you're doctoring up your bourbon with something

other than grains/water/yeast, you might be able to include it in your

"yeast nutrient" that's required to keep the yeast culture going.

I have a feeling that the sour mash process also keeps the same

strains of bacteria going, but that's just a hunch.

[jbutler]

Tim,

I think you got that right. Brewing supply houses almost universally have their house brand of "yeast nutrient" and are almost always secretive about it's ingredients. It's usually just a small bottle of white powder containing anthra ... I mean calcium carbonate, amongst other things. I've always thought about sticking a piece of litmus paper into it, but just havent done it. I'm pretty sure I've got some of the stuff in stock ... I'll give it a shot, then let y'all know of the outcome.

Cheers,

Jim Butler

Straightbourbon.com

[cowdery]

Remember that sour mash evolved in era when the science of what was happening was little understood. Although there might be more efficient ways to accomplishing the same thing today, there's got to be an "if it ain't broke, don't fix it" attitude at work. Also, we know there are still more than a few mysteries to bourbon-making, another reason not to tamper with success.

As I understand it, although the mash is monitored carefully for the presence of unwanted microorganisms, the sour mash process does a pretty thorough job of keeping them out by conditioning the mash so it is hospitable to the wanted bugs and hostile to the unwanted ones.

<A target="_blank" HREF=http://cowdery.home.netcom.com>--Chuck Cowdery</A>