Sweet Mash -vs- Sour Mash

[mickblueeyes]

Pepcycle, I should have been more clear. Yeast don't need it for fermentation.

[mickblueeyes]

Bobby C, I corrected myself on the hops used in the yeast mash. However, the use of lactobacillus in the yeast mash, will affect the rest of the mash.

[Gillman]

Just a few further thoughts based on additional reading. The role of bacterial action in backset cannot be overlooked. Traditionally (1800's) backset no doubt contained lactic acid (via the action of naturally occurring lactobacillus), and no doubt still does on a controlled basis. Also, I feel wild yeasts may have been at work sometimes in the old backset, hence its appeal for home distillers looking for a yeast substitute in 1818. Today, backset is heat sterilised before being added to the mash and will not have live yeast in it, but its acid levels from the action of lactobacillus may hold the key to its continued use, that and its source of any additional fermentables as earlier discussed. We know yeasted mashes work optimally at a certain pH level. Too much or the wrong kind of lactobaccillus culture will prevent a proper fermentation (the yeast can't work), but the right and proper amount will facilitate fermentation: this is what I understand Chuck Cowdery to have said earlier and that is undoubtedly correct. Specifically, there appear to be certain bio-chemical pathways shared by the by-products of yeast and certain beneficial, symbiotic bacteria. Hence the malolactic fermentation methods, innoculation of mashes with lactobaccillus culture and the continued use of backset due to its natural acidity. The chemistry and biology of these processes are dauntingly complex. I await further information (whether from laymen or scientists) to elucidate one of the key processes in making bourbon what it is.

Gary

[cowdery]

taking backset is a traditional methond of pH regulation, nutrient-rich water source and a source of heat to warm the mash.

I'd say that's a fair statement.

To really understand, you have to go back to 1840 or thereabouts. The big problem distillers have is consistency. Even if the distiller controls his yeast properly between batches it can get away from him during the actual fermentation, primarily due to interference from wild yeast. He discovers that backset seems to control this, leading to a more consistent beer from batch to batch.

I have been told that today they probably could control the process in other ways and people are always tinkering, but there's a strong bias to just stay with what works.

[cowdery]

At the outset of WWII, some bourbon distilleries tried to convert themselves to the production of industrial alcohol. It happened again in the 70s when bourbon sales collapsed. Both times they had a hard time making the conversion. Bourbon distilleries are not about using the most efficient and economical method to convert grain into alcohol. They are about making quality whiskey. If you want to know the most productive way to convert corn into alcohol, go to one of the distilleries in Iowa or wherever that makes industrial alcohol. I imagine they don't mess around with nonsense like backset.

[mickblueeyes]

I can't really see how it would be a problem to convert to distillation of industrial alcohol. Did they use pot distillation at that time? I thought pretty much all pot distillation had been phased out by then, with a few notable exceptions. Column distillation 5 times will yeild close to industrial alcohol.

I don't think backset really has anything to do with distillation, just regulation of the mash, and if that is the case, then most distillers would use that process for the mash.

[mickblueeyes]

Gillman, another excellent point. If lactobacillus are utilized at any point in the fermentation, whether prepping yeast or in the mash, it will affect flavor.

[cowdery]

All I was getting at is that making bourbon is different than making alcohol and some of the process is taken on faith, "because that's how my daddy did it."

[mickblueeyes]

Ahh. . .I see what you were getting at. . you are correct!

[tdelling]

Hello, StraightBourbonians!

I've been in the Caribbean for two weeks, and didn't have a chance to
do any recreational web-surfing. It looks like you've been rather
busy! This is a most excellent thread!

>Where are you Tdelling? You know this stuff cold.

That's very flattering! I'm really just a whiskey enthusaist with a
predisposition towards chemistry, a voracious reading habit,
a do-it-yourself attitude, and a few homebrewer friends.

I'm very glad that there are now other people on StraightBourbon
with an enthusiasm for bourbon chemistry. I remember getting
funny looks around here for saying "gas chromatography".

It looks like you guys have pieced together Sour Mash pretty well
without me! The one thing I've learned about whiskey is that the
more you learn about traditional techniques, the more the mystery
deepens.

Just a few words:
1) As someone pointed out, whiskey mash is indeed absolutely crawling
with lactic acid bacteria. This is a totally foreign concept to
homebrewers, who try their darndest to keep such things out, and just
throws a monkey-wrench into their understanding of the bourbon process.

2) Yeast are interesting creatures. Not only are there huge variations
between strains, but a given strain will also behave differently depending
on how it was propigated. Availability of oxygen is an important variable
here, as are nutrients, pH, temperature, etc. So the mysterious and
superstitous methods for yeast propigation are important.

3) I am only just beginning to understand the history of distilling
from a scientific point of view, but it looks like things such as
the sour mash process become infinitely more interesting and complex
when historic (what we would call "crude" and "uncontrolled") techniques
are used.

Tim Dellinger