Oils in Bourbon

[Gillman]

Mike Veach, in earlier posts on this forum, and Chuck Cowdery in his book, have commented that bourbon from decades past stretching to pre-Prohibition times tasted and looked (in the glass) noticeably oilier than bourbon today. Amongst the congeners of non-rectified alcohol are various oils (fusel oils so-called) that probably accounted for that taste and texture. It is a goal of modern distillation largely to eliminate these from spirits, however. When thinking of this I was also pondering the fact that some Irish whiskey is noticeably oily in taste and texture: the potstill Redbreast comes to mind in particular. I note that such oiliness in Irish whiskey makes the drink fuller, softer, easier to swallow. Contrarily much modern bourbon is not oily. Its texture often depends on wood sweetness (good as far as it goes) but sometimes even quality whiskey feels a bit rough, too "clean" in this respect. I am wondering if modern bourbon distilling, albeit that it meets the legal standards for bourbon, may be rubbing out the oily quality of whiskey. The 1800's whiskey blending manuals warned (for health reasons) against adding glycerine to neutral spirits to imitate whiskey. The injunction shows however that a smooth, slippery texture was considered part of old time whiskey taste, as Messrs. Veach and Cowdery seem to have confirmed by sampling whiskies bottled many a year ago.

I decided to add a few drops of Mazola corn oil to a glass of bourbon - what better oil to add than one from corn? Modern oils are refined to make them mild in taste, but Mazola tastes to a degree of corn and offers certainly the texture of a true oil. It is remarkable how this improved the bourbon. I added literally only a few drops to two fingers of whiskey. It made it go down better than normal, it deepened the body and smoothed down the ethanol edges. I believe I came close to duplicating the oleogineous aspect of old whiskies that Mike and Chuck wrote about.

This whiskey - but not the imbiber - was well oiled.

Gary

[cowdery]

Interesting observations and certainly it is correct that as the ability to "tune" a still has become more sophisticated, distillers have eliminated some of that oiliness. Most people, even people who like a robust and flavorful whiskey, didn't like that "oily" flavor.

It might, however, be a leap too far to assume that "oiliness" as a taste in a whiskey comes from oils. I'm not saying it is, but it might be, an argument I will support with the simple statement: "There aren't really any raisins in there either."

But you are also right about modern white dog, especially from certain distilleries, being very clean. I have noticed this recently with the Weller Centennial and 12-year-old. I'm getting a clean, sweet flavor from them that is otherwise almost as flavorless as simple syrup. There's a little bit of wood, but not much, so their main attraction is how clean they are.

[angelshare]

Most intriguing, Gary! Whether your theory is correct or not, I think we will likely try this sometime soon.

[Bamber]

That's a crazy experiment and a very interesting idea Mellow Corn is almost like drinking Mazola, but it's pretty good. It looks and tastes to a large degree like corn oil. To pick up on Chuck's point, it would be very interesting to determine the actual fat content (i.e oil) of this whisky. I'd wager it's around nil but that stuff is the oiliest whisky I've ever drunk by a country mile.

[Gillman]

I think in fact fusel oils are related to other types of oils (petroleum-derived) we are familiar with. Redbreast potstill has odours and flavors very reminiscent of such oils, some say linseed oil. (Which makes me wonder why linseed though, I am not even sure what linseed is. It is like those wines that are famously bramble-tasting; as Father Henriques, the American wine writer, once wrote, "when was the last time you had any brambles?").

If as stated the Mellow Corn tastes oily that makes sense to me because young whiskey won't have the fusel oils (or much of them) rubbed out by aging. Aging can change those chemicals into esters and other more pleasing compounds. True, fusels can be disagreeable (and plumb dangerous if present in too large concentrations) but I was thinking too of their (presumed) contribution to texture and body, hence my Mazola experiment. Aging of course would have done its work in the old days just as now but I am speculating that new whiskey back then had more fusels than new whiskey today. And therefore, long aging in the old days wouldn't have removed all the fusels because there were so many to strat with. Also, Chuck, you wrote in your book of a pre-Prohibition 17 year old whiskey that didn't taste that old: maybe it was very congeneric to begin with so that 17 years only took out a part of the congeners; thus, a 17 year old product then might be more comparable to an 8 year old product now. On the other hand, we have read of four year old products of that time that tasted much more mature than a four year old product of today, which cuts across what I just said, I think. But I think too each whiskey then may have had its own explanation for how it evolved. Small plants may have produced congeneric monsters which needed 15 years or more to start taming. Others may have produced more refined but low proof products that aged beautifully in four years. The wood used then probably was naturally seasoned for longer than today (for those whiskeys aged in all-new wood, not all were) so again a further variable. The more I learn in whisky, the more I don't know..

Gary

[tdelling]

This is a really great observation! I can't wait to try the corn oil
addition myself... we use olive oil for pretty much everything, so we
don't have any corn oil around.

I wonder how oiliness effects "mouthfeel" and the sensation of "dryness".
Although I've read a lot about taste (sweet, sour, salty, bitter... umami)
and smell, I haven't really read much about mouthfeel. I would guess
that viscosity and umami might play a large role in that, but oilyness would
certainly have an effect. I would guess that oiliness might balance tannic
astringency and make a less dry drink... but again, this is speculation.
I'm excited to add corn oil to EC 18, which is pretty much as dry as it
gets (at least in my collection).

One of the problems with talking about oil content and oiliness is the
definition of exactly what an oil is. There are lots of definitions
(most centering around saturated hydrocarbons of various lengths), but
I suppose a more functional definiton based on taste tests or a given
sep-funnel extraction might be more appropriate.

Corn is, of course, a VERY oily grain, and so distillations of corn mashes
are in many ways different than, e.g., barley mashes.

I tried a little sip of Cointreau (triple sec) to try to calibrate my
"tongue" with respect to oiliness, since it's got a lot of citrus oil
in it by design... but it's also got sugar in it, so I think it's not
an apt comparison to whiskies.


Tim Dellinger,
always interested in the science of distilled spirits