Chill filtering of Whiskey

[Jake Holshue]

I know the Scots are very proud of their whisky. Many of them are banding together against chill filtering their product. I have seen their statement on their bottle "non-chill filtered". Any thoughts on this for American whiskey? Do you think the average consumer cares? If you don't chill filter, do you bother to put it on your label?

[porter]

it slips my mind, but someone mentioned here selling non-filtered product, slightly cloudy. Other than appearance I really prefer the unfiltered products.

Why haven't we seen this on the shelves?

[MG Thermal Consulting]

Depends on what the unfiltered "stuff" is, I guess.

You take the "stuff" in cloudy wine and that is tartaric acid crystals, the sediment that can make some people sick.

I have sold glycol chillers for cold filtering, so it is not uncommon. The glycol is supplied at around 25F, so it is usually a stand-alone chiller for that part of the process, and of course, another expense.

[fermental]

So how many small/craft distillers are actually filtering their whiskey?

If you do filter, what process and equipment do you use?

[PeteB]

As I have just started diluting and bottling my first aged whiskies, this subject is of interest to me.

I have "no chill-filtration" on my bottles.

I have gathered from discussions with other distillers that the cloudiness (louching ? flock?) is mainly oils. Oils are part of the flavour profile so make a more interesting taste.

I haven't seen any explanation here, although there was quite a bit of discussion on Gin Louching which I assume is similar.

This is the way I understand it at present,

Without chilling, a flock will often form after dilution,but it takes many weeks. Diluted spirit cannot hold as much oil etc in solution so they form crystals or flock.

The colder the liquid is, the less soluble are the oils so they crystallise out very quickly, and more of the oils will crystallise out leaving even less flavour.

One local distillery lets their diluted spirit rest at ambient temperature for about 8 weeks, then they carefully decant the clear whisky off the top before normal filtering.

Another lets their spirit rest for almost as long then stirs the flock back into the bulk then filters to 0.5 micron.

I put a bottle of diluted whisky in my coolstore at -1 deg C (30 F) and the next day it was very cloudy. I shook the bottle and broke up the clumps and it went clear. Put it back in the cooler and expected the flock to reform but after 2 weeks it is still clear.

Anyone care to suggest what is happening here?

I would also like to know the technique that small distilleries are using for chill filtering. You certainly have less risk of "floaties" forming in the bottles.

[Valerii_Fedorov]

It is rather do not matter of oils, but colloidal stuff and nonorganic cations, such as calcium, iron, copper and so on. That is why chilling and after it some time of standing at this low temperature and then filtering is very important for stability both brandy and whiskey.

[bluestar]

Not oils, mostly flocculation of proteins and some wood extractives. We only see it in the barrel aged product, never in the bottled new make. You can often agitate it back into solution (or at least, de-flocculation). We have tried chilling before filtering, does reduce effect. We filter either way at 1 micron.

[Valerii_Fedorov]

After chilling and exposure some time at cold (for instance for wine brandy t=-8-12 C and time is 7-14 day) would be better filtrate by plates through press-filter, but the plates should to be treated by solution of citric acid in order to remove calcium from the cellulose plates. But before the bottling undoubtly better to apply filter elements of cartridge type.

[PeteB]

Not oils, mostly flocculation of proteins and some wood extractives. We only see it in the barrel aged product, never in the bottled new make. You can often agitate it back into solution (or at least, de-flocculation). We have tried chilling before filtering, does reduce effect. We filter either way at 1 micron.

With some scientific evidence I could be convinced otherwise, but at this stage I am still going with flocculating oils. I double distill with alembic pot (no plates) and after the first run there is always a very fine oil slick on the low wines, not visible after the second run. I think some of it has been dissolved in the higher ABV. My un-aged White Dog still forms a floc when I dilute it, so it is not just from the barrel.

You mentioned proteins, my nephew is doing a lot of work in the fish oil industry. He chills and flocculates the oil which traps the proteins that cause a lot of the "fishy" smell and taste, then filters it out.

Does anyone have any links to evidence that chill filtering does change the taste of whisk(e)y, or is it just an excuse if a bit of cloudiness forms in the bottles?

[Valerii_Fedorov]

I suppose, here are two different by nature phenomena. The first one, when in clear distillate are oils as a products of the distillation, which are dissoluting when content of alcohol is increasing and are visible in spirit when content of ethanol is decreasing. For instance, 80 PROOF visible "oils", 86 PROOF-fully dissoluted ones and spirit is transparent.

But when we aging the spirit in barel, here take place flocculation and opalescence on the base of proteins, other organic compounds and some wood extractives. Of course, in the case of chilling it is possible remove by filtration with plates these organic colloidal compounds, as well as organic and nonorganic salts (and other compounds) of calcium, iron, copper.

In any case filtration after chilling by plates does not remove the "oils". I think chill filtering does not worsen both taste and smell of whisk(e)y.

[Roger]

Valerii - love your interest , but you English is killing me:)

Dissoluted: Full Definition of DISSOLUTE

: lacking restraint; especially : marked by indulgence in things (as drink or promiscuous sex) deemed vices <the dissolute and degrading aspects of human nature — Wallace Fowlie>

[bluestar]

With some scientific evidence I could be convinced otherwise, but at this stage I am still going with flocculating oils. I double distill with alembic pot (no plates) and after the first run there is always a very fine oil slick on the low wines, not visible after the second run. I think some of it has been dissolved in the higher ABV. My un-aged White Dog still forms a floc when I dilute it, so it is not just from the barrel.

You mentioned proteins, my nephew is doing a lot of work in the fish oil industry. He chills and flocculates the oil which traps the proteins that cause a lot of the "fishy" smell and taste, then filters it out.

Does anyone have any links to evidence that chill filtering does change the taste of whisk(e)y, or is it just an excuse if a bit of cloudiness forms in the bottles?

Well, other than the fact that I am a scientist, I am not going to give you a slew of references. But proteins will go back into solution (deflocculate). Oils will not. And oils don't flocculate, not physically possible, unless they do so with other macromolecules, like protein. In which case it is protein flocculation with oils. Oils separate on their own either by going into suspension (not the same a flocculation) or just phase separating. The results look different, even to the naked eye. Oil suspensions look evenly cloudy, like when you louche absinthe. Protein flocculations usually end up in lots of floating, wispy, cloud-like fragments, that will have a tendency to settle to the BOTTOM of the bottle. Oils, if they separate (come out of suspension) will float to the top.

Flocculation (in polymer science): Reversible formation of aggregates in which the particles are not in physical contact.

So in your case, is it homogeneous, settling to the bottom, or floating to the top? That usually can determine which phenomenon (and which material) it is.

I see the same effect when making my corn whiskey as you describe: corn strip will produce significant amounts of oils and waxes that appear in the tails. We get an oil slick on the top of new make in the latter stage, and we get cloudy suspensions at the very end of the tails. So I am not saying there are no oils in your product, of course there are. But they don't flocculate.

I don't see any flocculation in the production of our corn whiskey if unaged, but rested in SS. I do see flocculation in the bourbon made from the very same new make, although not excessive. This leads me to suspect the proteins might be leachate from the barrel. But I can't rule out they were in the new make and modified by aging in wood.

[Valerii_Fedorov]

Valerii - love your interest , but you English is killing me:)

Dissoluted: Full Definition of DISSOLUTE

: lacking restraint; especially : marked by indulgence in things (as drink or promiscuous sex) deemed vices <the dissolute and degrading aspects of human nature — Wallace Fowlie>

Thank you, Roger. Of course, sometimes my mistakes in English are quite ridiculous.

[kkbodine]

Depends on what the unfiltered "stuff" is, I guess.

You take the "stuff" in cloudy wine and that is tartaric acid crystals, the sediment that can make some people sick.

Off topic but I have never heard of people being sickened by tartaric acid crystals. Tartaric acid is a main acid in grapes.

[Valerii_Fedorov]

I think, it is salt of the acid: potassium bitartrate.

[MG Thermal Consulting]

Many people with food sensitivities get severe headaches and stomach/colon distress from wines with excess sediment.

It is fairly well known effect.

[Roger]

Many people with food sensitivities get severe headaches and stomach/colon distress from wines with excess sediment.

It is fairly well known effect.

I was wondering about this very issue the other day. Not necessarily the sediment, but instead : what happens to the Heads, Hearts , Tails, in wine ?

Is it all being consumed by the wine drinker ? Many people seem to believe they are "allergic " to wines and things therein like sulfites, which give them head aches. Are they instead merely experiencing the effects of congeners that are distilled out in high proof spirits ?

[MG Thermal Consulting]

I do believe there is something to do with sulfites plus something(?) else.

I was on medication that was a sulfa-based medication and used to get some doozy headaches and generally had to restrict any wine drinking ( maybe the amount of sulfa in my system added to it).

I don't think you can find any "off the shelf" wine that doesn't include sulfites- so something does muddy up the issue.

[Valerii_Fedorov]

What is allowed limit of SO 2 in american wine?

[porter]

I was wondering about this very issue the other day. Not necessarily the sediment, but instead : what happens to the Heads, Hearts , Tails, in wine ?

Is it all being consumed by the wine drinker ? Many people seem to believe they are "allergic " to wines and things therein like sulfites, which give them head aches. Are they instead merely experiencing the effects of congeners that are distilled out in high proof spirits ?

Good point on the heads. Wine is 24proof, so the methenol heads are still there just not as concentrated.

I run a beer/wiine making supply shop and get folks in who are allergic to sulphites, or so they say. One patron says 2oz of wine will make swelling around the joints. But his own is not a problem. He uses standard recipe just no addition of sulphites like the wineries do.

I also have 2 people who can't drink any 'colored' distillate. White rums, vodka, etc is fine. Problem is with the aging on wood. Similar problem with very small amounts causing reactions.

[bradocaster]

We have an issue with our bourbon. it's bottled at 90 proof. we filtered it using a 1 micron filter. now we have snowflake/jellyfish looking things suspended in the bottles. we are needing to bottle more and want to get it right. our chiller only chills to 35f. is that cold enough to chill filter? is this an issue that chill filtering will solve? maybe a .45 micron filter fixes it? thanks for the great info.

Brad