Q&A #2 with Four Roses Master Distiller - Jim Rutledge

One question that has rolled around the bourbon sites has to do with chill filtering and the effects it has on the bourbon. I've never been able to get a reasoned answer when asking the enthusiast population but the question was posed to Jim and his response made for some good reading.

Q: Jim, there has been an ongoing debate for some time as to the impact of chill filtering on the flavor and mouth feel of whiskey, Some claim it has little impact others say it has little. Do you feel chill filtering impacts your bourbon and if so in what ways? Does Four Roses chill filter every bourbon that has water added to it

JR: Chill filtering came about in `70's after the minimum strength of bottled distilled spirits was reduced from 86 proof to 80 proof. The more water added to reduce the strength the greater the probability of fatty acids precipitating out and it didn't take long at 80 proof for this to be discovered. The precipate first forms a haze and eventually visible solids floating in the liquid. The solids resembled a small piece of cotton; I call them "puff balls." I was involved with the first incidence of fatty acid precipation with a Seagram shipment, via rail car, to Washington or Oregon. The rail cars were stranded for more than two weeks in Idaho in late January after a blizzard with temperatures well below zero. Soon after R&D finished their studies of he returned bottles Seagram began chill filtering Bourbon that was bottled below 90 proof. Fatty acids are present in nearly all foods and are Absolutely Not a health issue, but when a precipate develops it is definitely an aesthetic and marketing issue. One of the reasons it was difficult to first get a grasp on the seriousness of the issues is when a bottle is disturbed (a little swirl will do it) the fatty acids quickly go back into solution and disappear.

FRD chill filters YL and both Small Batch and Single Barrel, and I've tried to explain the NON-necessity to chill filter both higher strength labels. We don't chill filter any of our Limited Edition offerings or barrel strength private barrel selections.

Chill filtering involves lowering the temperature of product to below 20 degrees F. and letting it set for ~24 hours. After that period of time the fatty acids are not visible to the naked eye, but they have begun to solidify and may be filtered. I'd far prefer Small Batch, and especially Single Barrel were Not chill filtered. With removal of fatty acids some flavor, and body, are lost. In lieu of chill filtering some distillers add a chemical to generate a precipate. Of the two options I prefer chill filtering - even if it is far more costly....

I don't think it makes a difference what type equipment is used to chill the Bourbon, except from an efficiency perspective. The major change we made a few years back was in our filtering media which after changed aided us by not removing as much color in the process. Flavor was not impacted - once the fatty acids are gone they're gone. I'm an advocate of chill filtering Bourbon equal to or less than 86 proof, but when it's not necessary I'd far prefer Not Chill Filtering. 

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