Mash thickness

[Gillman]

Good article by Chuck Cowdery in the current Malt Advocate on the nature of continuous distillation and its role specifically in the manufacture of bourbon. A representative of Vendome (the renowned still manufacturer in Louisville) is quoted that in the last 45 years, the amount of water in mashes has fallen by approximately half (from 44 gallons per bushel originally to mid-20's currently).

This is done to economise on energy costs (it costs less evidently to heat less water).

It seems a still can vaporise the thicker mashes just as well, or maybe the extra cost to do so efficiently is much less than to process a mash holding 44 gallons per bushel.

I find this interesting and I wonder if the taste of new spirit is different when made in the newer way.

Gary

[MGades]

I hesitate to comment because I haven't read the article (is it the Third Quarter 2007?), but what is the relationship between the concentration of the mash and the content of the beer? (Isn't it the Beer and not the Mash that is introduced into the still?)

Since distiller's beer is now about 10% ABV, does this mean that the beer used to be about 5% ABV 45 years ago when there was 2x as much water in the mash?

[cowdery]

I can't comment on Gary's taste question, I don't know. Contrary to the PR departments that like to portray the distilleries as never-changing, they are in fact always trying to "tweak" the process. My assumption is that they reduced the ratio of water to grain gradually and didn't find a negative affect on taste.

I can perhaps clarify a little bit for MGades. With American whiskey, the mash goes into the fermenters and ultimately into the still intact, i. e., containing grain solids, so the mash is the beer. Nothing changes except the addition of yeast and the conversion of sugar into alcohol, but the water:solids ratio does not change. I guess it makes sense, logically, that a thicker beer would have a higher ABV.

Remember, the whole object of the exercise is to concentrate the amount of alcohol by eliminating water. If you can eliminate some of the water by never introducing it in the first place, that's efficient. The main energy "cost" in the operation of a distillery is in boiling water, so less water to boil, less cost.

Yes, it's in the Third Quarter 2007 issue. Cover headline is "Judged by the Cover."

[jeff]

Not completely related to whiskey, but here is some information on mash thickness as it relates to beer:

The grist/water ratio is another factor influencing the performance of the mash. A thinner mash of >2 quarts of water per pound of grain dilutes the relative concentration of the enzymes, slowing the conversion, but ultimately leads to a more fermentable mash because the enzymes are not inhibited by a high concentration of sugars. A stiff mash of <1.25 quarts of water per pound is better for protein breakdown, and results in a faster overall starch conversion, but the resultant sugars are less fermentable and will result in a sweeter, maltier beer. A thicker mash is more gentle to the enzymes because of the lower heat capacity of grain compared to water. A thick mash is better for multi-rest mashes because the enzymes are not denatured as quickly by a rise in temperature.

That is taken from John Palmer's How to Brew, an excellent resource for home brewers. If the above is at all applicable to whiskey "beer", then it would seem counterintuitive for the distillers to mash thicker, as a thinner mash would produce greater yields.

[Gillman]

Good point, Jeff.

Could special enzymes be added to a thick bourbon mash which would resist the inhibitory quality noted by Palmer? Home brewers (at any rate) wouldn't do this, but commercial brewers, and distillers, do so on occasion I understand.

Could the new makes (and therefore the aged ones) made by either process taste the same? Seems unlikely, but how they might differ I cannot say...

Gary

[barturtle]

Not completely related to whiskey, but here is some information on mash thickness as it relates to beer:

That is taken from John Palmer's How to Brew, an excellent resource for home brewers. If the above is at all applicable to whiskey "beer", then it would seem counterintuitive for the distillers to mash thicker, as a thinner mash would produce greater yields.

This is my first thought, too. As using less water would mean that the starches would reach stasis (the same amount in the water as in the grain) at a level that would leave more in the grain that would never get fermented, this is wasteful.

This lossy stasis level would also present itself in the oils and such that are extracted during the mashing process.

The question is then how much difference in total starch/oils/other good stuff is lost...Some quick thoughts (without any evidence to back them up) tells me that to take the remaining fermentable/other materials from say 4% to 2% would require twice the water...at some point this doubling of water(an exponential curve) has to hit a point of diminshing returns...where the point at which the losses in the beer start to show up in the minimal amounts of flavoring agents that make it through the still, I can't say...but I'm betting one of the labs at the distilleries has a good idea.

[cowdery]

Some distillers do use synthesized enzymes but Jack Daniel's, for one, makes a thick mash and does not use enzymes.

Wouldn't the fact that American whiskey mashes are cooked affect the statis level and allow the starch to be almost completely dissolved, regardless of the water content? Wouldn't this fact also make the comparison to beer mashes irrelevant?

[barturtle]

Wouldn't the fact that American whiskey mashes are cooked affect the statis level and allow the starch to be almost completely dissolved, regardless of the water content? Wouldn't this fact also make the comparison to beer mashes irrelevant?

I see where you are coming from with this...imagine cooking pasta with very little water...the water won't be able to take away enough starch and will thicken into a nasty mess...a little more water and while you might not have a mess in the pot, the pasta itself will still be starchy and stick together...a lot more water and you have well cooked, non-sticky pasta.

In this illustration the middle condition is the problem I think could be ran into; the water and the pasta has reached the point where both contain the same amount of starch...lets call this 20% starch...if it took 1 gallon to dissolve that much starch out of the pasta(and at this point the pasta has 20% starch too), then it would take 2 gallons to take it to 10%...4 to 5%, 8 to 2.5%...change this formula to thousands of gallons for the volumes used in a distillery and you start to see an issue in how much water you can use and how much it takes to reclaim the hidden percentages in the grain.

The starch would only be dissolved to the point at which both the grain and the water have the same amounts in them...IIRC water weighs 8lbs/gal Jeff's thinner mash of 2 quarts per pound of grain means that it's a weight ratio of 1/4 grain/water...halve the water and you might not have enough to dissolve enough starch out and would then be wasting lots of fermentable material....but you'd have a great glue for doing paper mache.

Of course, I could be completely wrong about all of this...well, not the using plenty of water to make pasta part...but maybe the mashing stuff...

[Gillman]

Cooking just solubilises the starches, so I am not sure the analogy with beer mashes isn't a suitable one. In the end, you still have a given amount of starchy material to convert just as with a full barley malt mash, the only difference with distillers' mashes is they contain some unmalted materials (some brewers' mashes do, too, e.g. for Guinness).

I would think enough water is added even to a thick mash to ensure all the sugars are converted from the starch and run into solution. Probably in other words we are speaking relatively and the alcohol yield is the same in both cases, just more dilute with a thin mash.

Gary

[barturtle]

I would think enough water is added even to a thick mash to ensure all the sugars are converted from the starch and run into solution. Probably in other words we are speaking relatively and the alcohol yield is the same in both cases, just more dilute with a thin mash.

Gary

Ah, and that reminds me of one more thing...even if you are using enough water to capture the starch from the grain, are you using enough water to let the yeast eat it all before the alcohol reaches the point where it kills off the yeast?

[MGades]

Because the grains are milled and cooked, I'm not sure that it is accurate to say that there are two distinct compartments in the fermenting mash (grain, water). The grain solids that remain after fermentation are more likely to be just starch-free cellulosic cell-wall materials plus proteins and fats that are non-fermentable (although there is much current research into methods of making fuel-grade ethanol from cellulose).

Even if the more concentrated mash resulted in some unfermented starches, this might be an efficiency concern for the distiller, but that in itself shouldn't affect the quality of the distillate if a steam-column distillation is used. (in a pot still, it might be a different story)

What I was thinking is what Timothy suggests in his last post- as the alcohol level rises towards a toxic level to the yeast, the yeast metabolic processes may begin to be altered and the amount of non-ethanol products might be increased. Those non-ethanol compounds might be good or bad, if bad, it might be possible to trim them out with careful distillation, but this might require trimming away favorable components as well.

Modern yeasts can handle at least 10% ABV without trouble, but it seems like distillers claim to use very old yeast stocks/strains. Old strains might be more wild and in that case they would be less alcohol-tolerant. As a result, the old strains which were optimal for a 5% ABV mash might not be the optimal yeast for a 10%+ ABV mash.

[Gillman]

Sounds like a tall order for a thick mash: the higher the sugar concentration, the less the enzymes in the barley (and raw grains always have some, rye does anyway) will work well; the higher the alcohol concentration, the more likely the yeast is to be killed off early, affecting again yield. So how does thick mash work efficiently? Must be added enzymes and/or very efiicient yeasts, e.g., if JD does not use added enzymes but uses a thick mash, its yeast must be able to work well at higher ABV levels.

Gary

[MGades]

My opinion is that yeasts can make a world of difference in the flavor profile. Yeasts are what make the congeners associated with fermentation. Some are good and some are bad. Either way, this affects the qualitative aspects of the fermented product. Compare a fermented neutral fruit juice such as apple juice to illustrate the differences in flavor profiles. A wine yeast will produce a delicate, lightly floral, balanced, and refined product, while a beer yeast or wild yeast will produce a coarser, simpler, more rough product. A wild yeast will also cease fermentation at a lower %ABV.

A quality product could be produced with modern yeast and modern distillation methods, but I think that it would be impossible to do so without modifying methods from what was historically practiced.

[mozilla]

So, I'm sure there is someone at each distillery that is concerned with how this all will affect production costs. Are they more concerned with profits or flavor? How about the marketing group....what's thier opinion?

Jeff M.

[MGades]

So, I'm sure there is someone at each distillery that is concerned with how this all will affect production costs. Are they more concerned with profits or flavor? How about the marketing group....what's thier opinion?

Jeff M.

Anyone care to respond?

Personally, I appreciate any efforts to keep bourbon reasonably priced - but I'm still curious about the answer to this question.

[JeffRenner]

A few thoughts on mash thickness, cooking, enzymes, etc.

Even 22 gallons of water per bushel is a relatively thin mash by (home)brewing standards. A bushel of corn weighs 56 lbs, same for rye, and barley malt is 34 lbs. That means that a bushel of bourbon grain bill weighs about 53 lbs. Using 22 gallons (88 qts.) means about 1.7 qts./lb. (using American, not imperial measures).

Not all of a bourbon mash is cooked, only the corn and rye/wheat. Same with beer - adjuncts (corn or rice) in traditional American lagers are also cooked. Barley malt does not need to be cooked to gelatinize (made soluble) the starch. Of course, this means that most of a bourbon mash is cooked, but less than half of a adjunct beer mash. But I don't think this would make a difference - all the starch ends up gelatinized and accessible to the enzymes in both cases.

If you can eliminate some of the water by never introducing it in the first place, that's efficient. The main energy "cost" in the operation of a distillery is in boiling water, so less water to boil, less cost.

Exactly, but I'll point out that most of the water in a mash never gets boiled. The distillation stops when most of the alcohol gets boiled off, which occurs at ~173F., well below the boiling point of water. Some of the water is vaporized at that lower temperature, of course, but most is not.

I too am curious as to how this practice might affect the final product.

Jeff

[barturtle]

I'm not sure if Chuck was referring to the water used in distillation. I would think he is most concerned with boiling the water for the mash, as the corn is boiled for about 25 minutes before the temp is allowed to drop before the addition of the small grains.

[Gillman]

Even in the column though you would save energy by having less water to heat with steam. Even if the water (all of it) is not vaporised in the column, it is heated which requires energy.

I would think there must be a difference in taste of the new make when a dilute mash is heated in a column still vs. a thick one. There must be some difference from the relative concentrations of water in each beer, i.e., on taste and how vaporisation affects it.

Jeff is right of course that some water is vaporised at low temperatures. Some water does come over at under 212 F. in other words, and some alcohol(s) at higher or lower than their stated vaporisation rate, this results from the conjoining of different types of liquids (water, esters, acids, etc.).

Gary

[Gillman]

I was just reading something on a homebrewing site which suggested that enzymes behave differently in a thick vs. a thin mash. This happens for a variety of reasons including if I got it right mash temperature, pH levels and other sophisticated biochemical factors.

Here is the thing. Take a white dog produced by a thick mash process and one produced with a lot more water in the mash and column. Do they taste the same? If not, what are the differences? Can it be said that one method is preferable based on palate considerations alone? Even if they taste different, will that difference be manifest after years of barrel aging? If so, how will the difference manifest at the end of the pipe?

Gary

[bobbyc]

So, I'm sure there is someone at each distillery that is concerned with how this all will affect production costs. Are they more concerned with profits or flavor? How about the marketing group....what's thier opinion?

Jeff M.

I think it's safe to assume that no one in the industry begins the day with the thought, "Today I'm going to make a sub par batch".

That being said, the bean counters have done their work well enough in the past to kill some dear products.

As far as Profit vs Flavor it may come up, but the fine line is not to kill the goose as it were. Less flavor would translate to Less profit at some point.

[cowdery]

Arguably, the demise of bourbon in the seventies can be attributed, in part, to a pursuit of cheapness that sacrificed quality. Examples would be the use of all-stainless stills and the elimination of doubling.

[Rughi]

...the elimination of doubling.

Chuck,

Could you elaborate on this?

I've read reports on these forums about Barton and JD bypassing the doubler at times, but I'd not heard of this being an industry trend or a systematic way to cut costs.

I also wonder if bypassing the doubler is always a bad thing.

Roger

[cowdery]

As far as I have been able to determine, the rumors about JD are false. They always doubled. The rumours about Barton may be true, but I know they are doubling now. I heard on good authority that someone in Kentucky only recently resumed doubling. My source wouldn't tell me who, but I suspect Barton.

There was, when bourbon started to decline in the 1970s, a real race for the bottom. One of the things people did to cut costs was single pass distillation. It's no problem for the column still to give you whatever proof you want, but it's just not as good as the doubler at removing some of the key bad congeners, especially low boilers. Everybody who tried it either went out of business or went back to doubling because they realized the quality just wasn't there without it.

I have theorized that part of the rationale for Michter's calling its whiskey "pot still" is that they continued to double after the big distilleries in Pennsylvania, like Publicker, stopped. A doubler is a pot still.