Partially waxing a small barrel to limit evaporation/oxidation?

[tombombadil]

Hi!

My wife has agreed to get me a barrel for Christmas!

But I only have the patience/free time to fill a 5 gallon barrel.

I've been doing some reading about it and I've found that some beer brewers have been partially waxing smaller barrels to limit evaporation/oxidation.

Has anybody tried this with aging spirits in a small barrel?

I live in a very hot and dry place (single digit humidity most of the year).
One of the local micro distilleries reported losing 16% per year in his 53 gallon barrels.
I'm guessing it would be even higher in a 5 gallon barrel.
I would hate to do all that work and lose half of it in two years.
Maybe waxing the seams between each stave should reduce my undesired excessive evaporation loss without messing up the desired barrel aging effect too much?

[The Baker]

Just kicking this around...
Suppose your barrel is/ barrels are contained in a glass fronted superseded commercial refrigerator cabinet.
Possibly on its side, that might look prettier and be more practical. (So that the door/ lid lifts up).
Maybe on a slide-out mounting?
Perhaps with humidity control...
Would cost practically nothing...

???

Geoff

[CopperFiend]

What Geoff said sounds good. But I cant see any issues with waxing the seams, as long as no petroleum products contact the spirit, should be fine. Not sure how much you'll save though as a lot of the angel's share just wicks through the wood.

[NZChris]

Maybe you live in a climate that is better suited to clever aging in glass or SS rather than for aging in small barrels?

[SaltyStaves]

Not sure how much you'll save though as a lot of the angel's share just wicks through the wood.

That is not how barrels work. Wicking = wet. The outside of a barrel isn't wet unless there is a problem.

[zapata]

Wicking by definition or not, air enters and spirit vapor leaves the barrel through the plank as well as the seams. Which is what I think CopperFiend was trying to say. Whether it's a lot or a little probably depends more on the cooperage and luck of the draw on exact grain specifics in each and every plank. But that's beyond the control of someone with one barrel.

I live in a very hot and dry place (single digit humidity most of the year).
One of the local micro distilleries reported losing 16% per year in his 53 gallon barrels.

Do you believe this distiller? And did you ask about what happens to their proof? Do you like their whiskey?

The general consensus is that ethanol evaporation is not affected by humidity, but water evaporation will be. Consider that the gradient from ethanol inside the barrel to ethanol outside barrel is the same everywhere. So barrel proof increases in low humidity areas. A 16% per year angel's share if caused by low humidity then the bulk of that is water would lead to very high barrel proof remaining. Hand wavey guess if ethanol losses are remotely "normal"? 80% after 4 years!

Personally I would be suspicious of the claim. 16% annual loss means the barrel is half empty after just 4 years, and would have just 13 gallons after 8 years. Doesn't seem economically viable to me.

The other things that affect evaporation are temperature and airflow, and they should affect both ethanol and water. Is this single digit humidity locale also hot AF? That is might explain a 16% annual loss more than humidity alone, and might be more expensive for a distillery to regulate than humidity. Again, I'm suspicious of the number.

But even if you live somewhere hot and bone dry, will your barrel? Do you not have air conditioning? Can you not humidify a room, a tent, a box? And really, I gotta ask... Are YOU ok? I've been stuffy for the last week since humidity dropped to the 40's. Single digits? Can humans really survive it?

[CopperFiend]

Not sure how much you'll save though as a lot of the angel's share just wicks through the wood.

That is not how barrels work. Wicking = wet. The outside of a barrel isn't wet unless there is a problem.

Clearly the liquid wicks through the vessels in the wood, otherwise there would be no fluid loss. Obviously the outside of the barrel isnt wet, we are talking about tiny amounts and mostly where the quarter sawn wood has exposed external grain. If this is not the case, explain how liquid is lost via evaporation.

[chickenfeed]

Try oaking on glass then a short period of time in the barrel there are two parts to ageing. Oaking and evaporation Oak it to close to where you want it in glass then barrel it. I lose about 2 gallons our of a 5 gallon barrel. You want to lose that much. Thats when it gets good.

[SaltyStaves]

If this is not the case, explain how liquid is lost via evaporation.

Changes in barometric pressure force spirit in and out of the wood, but also opens the space between staves. This is where most of the losses occur.
That is why plugging them with wax is a bad idea. The only way it would be viable would be doing it to every second seam (which may slow the rate of loss). Otherwise the barrel simply won't perform its function.

[CopperFiend]

If this is not the case, explain how liquid is lost via evaporation.

Changes in barometric pressure force spirit in and out of the wood, but also opens the space between staves. This is where most of the losses occur.
That is why plugging them with wax is a bad idea. The only way it would be viable would be doing it to every second seam (which may slow the rate of loss). Otherwise the barrel simply won't perform its function.

If it opens the spaces between the staves, surely the 'outside of the barrel would be wet'. Clearly this is not the case, as you have already stated. This is indeed a very complex process and barometric pressure plays a part. Temperature plays a larger role. Your statement that fluid is forced into and out of the wood confirms my comment that the fluid travels through the wood and evaporates from the exposed end grain. This could also obviously occur if any end grain is exposed in the spaces between staves during micro shrinking. If the staves were to shrink enough to allow passage of fluid between the staves themselves, the barrel would clearly leak and large quantities of product would be lost. Furthermore, for capillary loss of fluid between the staves this would require a clear path of more than 0.01mm. Again, resulting in large losses.

[CopperFiend]

Waxing the seams (theoretically) would only have a small impact on evaporation of product. I havent ever done it as I make my barrels to be spirit-tight (obviously) and either ditch or remake those which are not. I'm sure a simple study could be done to find the impact this would have (though barrels are so different to each other that large sample sizes would be needed to get decent study power)

[SaltyStaves]

If it opens the spaces between the staves, surely the 'outside of the barrel would be wet'.

I'm not stating that fluid leaves through the micro-gaps between staves. They are an important pathway for both bringing in and expelling. Blocking them will be detrimental.

[Saltbush Bill]

Id agree that barometric pressure and temprature change probably plays the biggest part in forcing spirit in and out of the wood of a barrel. I dont think wicking is a great choice of words for whats going on in a barrel.
I know from experience with my own barrels that they are subject to large fluctuations in pressure on the inside.
There are times where spirit leaves the tap under a lot of pressure due to the build up of pressure inside the barrel.
Other times no spirit leaves the tap at all and a large amount of air is drawn into the barrel instead , which indicates a vacum inside.
Pressure is constantly changing due to climatic conditions.
On barrels that have less than perfectly air tight bungs I dont experience this.

[jonnys_spirit]

Bollox! It's either the angels sent by the whiskey gods taking nips along the way or you've got teenagers... What you need is a camera!

Cheers,
jonny

ps - congratulations on the barrel!

[zapata]

I've read at least one study on barrel stave vs. seam permeability, I think I posted it in the badmo thread a month or so back. The majority of permeability was indeed through the seams.

Regardless, un-waxed 5 gallon barrels have proven performance in the full range of "normal" climates around the world. If I lived in an extreme climate I'd either try it and see what my natural environment produced, or give the barrel a proven "normal" microclimate. Damp perlite wicks moisture into the air, and a loose tent or vented tub over both perlite and barrel would make a very easy low tech humidity chamber that still allows plenty of gas flow. Might even help raise the surrounding room closer to human friendly conditions.

[tombombadil]

Wicking by definition or not, air enters and spirit vapor leaves the barrel through the plank as well as the seams. Which is what I think CopperFiend was trying to say. Whether it's a lot or a little probably depends more on the cooperage and luck of the draw on exact grain specifics in each and every plank. But that's beyond the control of someone with one barrel.

I live in a very hot and dry place (single digit humidity most of the year).
One of the local micro distilleries reported losing 16% per year in his 53 gallon barrels.

Do you believe this distiller? And did you ask about what happens to their proof? Do you like their whiskey?

The general consensus is that ethanol evaporation is not affected by humidity, but water evaporation will be. Consider that the gradient from ethanol inside the barrel to ethanol outside barrel is the same everywhere. So barrel proof increases in low humidity areas. A 16% per year angel's share if caused by low humidity then the bulk of that is water would lead to very high barrel proof remaining. Hand wavey guess if ethanol losses are remotely "normal"? 80% after 4 years!

Personally I would be suspicious of the claim. 16% annual loss means the barrel is half empty after just 4 years, and would have just 13 gallons after 8 years. Doesn't seem economically viable to me.

The other things that affect evaporation are temperature and airflow, and they should affect both ethanol and water. Is this single digit humidity locale also hot AF? That is might explain a 16% annual loss more than humidity alone, and might be more expensive for a distillery to regulate than humidity. Again, I'm suspicious of the number.

But even if you live somewhere hot and bone dry, will your barrel? Do you not have air conditioning? Can you not humidify a room, a tent, a box? And really, I gotta ask... Are YOU ok? I've been stuffy for the last week since humidity dropped to the 40's. Single digits? Can humans really survive it?

I do believe the guy. I have no way of checking his math but he used to be an investment banker so I'm guessing it's accurate. It's also very hot here for much of the year.

Very dry and very hot makes for a lot of chapped lips but we're ok! We just drink a lot of water...

I was thinking about putting the barrel in a closet in my house so the temp will be fairly constant and there won't be much air flow. We keep the house under 77f all year so maybe my losses won't be as bad as the local distilleries.

[The Baker]

What Geoff said sounds good. But I cant see any issues with waxing the seams, as long as no petroleum products contact the spirit, should be fine. Not sure how much you'll save though as a lot of the angel's share just wicks through the wood.

Beeswax.

Geoff

[The Baker]

Just kicking this around...
Suppose your barrel is/ barrels are contained in a glass fronted superseded commercial refrigerator cabinet.
Possibly on its side, that might look prettier and be more practical. (So that the door/ lid lifts up).
Maybe on a slide-out mounting?
Perhaps with humidity control...
Would cost practically nothing...

???

Geoff

Afterthought:
Simple humidity control;
open the door for a while when the outside humidity level is desirable. G.