Vacuum assisted aging

[Copper top]

ok guys, my first real contribution to the forum, been reading so much my eyes hurt, done quite a few brews and results have been fair thanks to the great information from the group.

need some opinions on this topic "vacuum assisted aging" trying to create a whiskey using oak sticks so heres what i have done so far,

1 built a boka style still, but using it in pot mode
2, made a few batches of cornflake and also all bran wash - distilled and now have a couple of gallons to age using local english oak,
3, collected a very old dried out oak branch and cut it into sticks 100mm long x10mmx10mm baked the sticks in the oven @200 deg c for 2 hrs, then charded one side with a blow lamp
4, placed 35 sticks in each gallon demi john ready for ageing liquor is ABV 55%

now while i was doing this i had an idea i took a rubber bung and length of pipe and attached it to one of the containers, and sucked the pipe, while i was doing this, air bubbles could be seen coming out of the oak sticks and also causing some of them to float to the top, when i released the vacuum the sticks sank back to the bottom,

so what im thinking is ,while the container is under a slight vacuum and bubbles are being released the liquid is going into the sticks, maybe ageing slightly quicker than if they were left to it on their own?

so what im asking is
1, has anyone tried this before
2, am i wasting time on further experimentation, i did try a taste after about 4 days , the one under vacuum is slightly darker but only a tinge, but the mellow taste is very noticable

i was thinking of rigging up some sort of vacuum pump and a timer and having the process automated to apply vacuum for 12 hrs then vent for 12 hrs

any comments ?

[DAD300]

Using a vacuum you managed to saturate your food quickly and I'd say that was an o.k. thing. Nothing a week wouldn't have done.

Maintaining a vacuum over a longer period would risk removing desirable alcohol.

[FullySilenced]

Nuke it and leave it under vacuum if you want... leaving a vacuum pump on a quantity will remove the ethanol over a period of time and leave any H2O behind in most cases..

Happy Stillin

FS


KEEP ON NUKIN !!!

[thatguy1313]

I think pulling multiple, short cycles of a mild vacuum would be beneficial. Pull a vacuum, let it rest, release the vacuum, let it rest, ect. Essentially the idea behind nuke aging without nuking it. I wouldn't leave it under vacuum for any extended period of time.

[skow69]

+1 Seems like a sensible idea to me. You'd get the effect of the vacuum without the effect of the heat. (Whatever that may be.) And there won't be any evaporation any time the pump is not running. In fact you might lose less this way than what steams off in the microwave. I hope someone will try this as a comparison. Hell, maybe I'll try it.

[NZChris]

That is more than ten times more oak sticks than I have ever used. I have over-oaked and a week with too much oak is hard to fix.

55% ABV is low for aging and will extract different flavors than higher ABVs.

Don't confuse aging with flavoring. Aging is more complex than just making oak tea out of your white dog.

[thatguy1313]

Good catch nzchris. That is a shee-ton of oak.

[Copper top]

thanks guys for the replies,chris seems i may have truly over oaked,but time will tell as my sticks have a surface area 10x1x4 =40 cm sq and as they are quite thin i decided that the actual influence area would only =20cm sq so this gives me roughly 130 cmsq per litre which i read somewhere was quite a good starting point, but i will let you know how it turns out,
another thing that might save the day is the oak i used was a branch about 3 inch diameter although it was well dried out it may lack the potency of the trunk wood, maybe someone can advise me on this
my idea was to try and recreate the action of constant changing temperatures contracting and expanding the barrel moving the liquid in and out of the oak, at the moment all im doing is sucking the end of the pipe and folding the end to close it i doubt little evaporation of spirit is likely, every time i do this thousands of tiny bubbles are streaming to the surface, just been out to the garage where i keep the liquer its about 10 deg c out there at the moment, had to have a little sample there is definitely a difference to the jar that has been subjected to the vacuum, mellow /smooth , very drinkable and thats only been 5 days ,
it maybe as dad suggests if i had left it a week it would have done this itself,
as fullysilenced suggested nuking i have tried this on a ltr bottle, yes it gave it oak and colour but the taste was a little harsh, again i need to try with some oven roasted oak

im thinking of rigging up a small refrigeration pump that i have, but it wont be this week

[skow69]

OK, I tried it. And the results were actually not at all what I expected. The procedure didn't have scientific rigor, but I was careful enough that I think the findings are representative of the ideas in questions.

Procedure
I started with new make bourbon at 64% ABV, 4 days old. It had been kept in a single jug with oak sticks. I took three 16 ounce samples and put them in quart jars labeled VAC, NUKE, and CONTROL. Each jar got one stick of toasted oak 2 1/2" x 1" x 1/4" and one stick of charred oak slightly smaller. The VAC and NUKE samples were subjected to 6 treatments over a period of 9 days. Each treatment consisted of the following: The NUKE sample spent three minutes in the microwave. Then it was capped and left to cool naturally, usually overnight. The VAC sample was poured through a funnel into a vacuum chamber. Vacuum was applied to 26 inHg (+/-1), clamped off, and allowed to bleed off slowly over a period of about 20 minutes. Then it was poured back into the jar. The other two samples remained in their jars throughout the procedure. At 4 different times along the way I added two ounces of water to each sample for a total of eight ounces each.

Pics

start

1 treatment

2 treatments

3 treatments

4 treatments

5 treatments

[skow69]

5 treatments

6 treatments

6 treatments

Here is what I recovered at the end:
CONTROL......23 3/4 oz @ 46% ABV
NUKE...........19 3/4 oz @ 40% ABV
VAC.............21 1/4 oz @ 43% ABV

Conclusions
Summary: Using vacuum to accelerate oaking is hard on your liquor. Using the microwave is REALLY hard on your liquor.

Assuming the oak sticks soaked up 1/4 oz from each sample, the vacuum treatment consumed10.4% of the volume. Some of that must be attributed to drops left over in the funnel and vacuum chamber with each treatment, but only a very small portion, like a quarter ounce max. The microwave treatment consumed 16.7%. The corresponding drops in ABV are consistent with the fact that alcohol is more volatile than water.

In the photos you can see the NUKE sample become increasingly hazy with each treatment. After removing the oak sticks I ran each sample through a triple coffee filter. There was no noticeable change to the NUKE haze and the residue on the filter was identical to the other two. It is now in long term storage to see if anything will settle out of it.

In a (mostly) blind taste test, 3 out of 3 of my drunken friends preferred the VAC sample, but it was really just a competition between VAC and CONTROL, because the haze identified the NUKE sample and nobody took it seriously. I found the VAC sample was a little smoother and more woody than CONTROL.

It appears to me that vacuum oaking probably makes young whiskey a little better than corresponding white dog, but I was impressed with how well the CONTROL kept up. I suspect that within a few months, or maybe a few weeks, it will be impossible to tell them apart.

I will not be using the microwave again.

I can hear thousands of voices saying, "Nuking never did that to mine." and you could well be right. I encourage you to try it again with your next batch. Keep a control jar aside for comparison. Take pictures and post them here. Help me understand where I went wrong. Replicate the procedure. It's what scientists do to prove each other wrong, or right.

Skol,
skow

[ga flatwoods]

Don't confuse aging with flavoring. Aging is more complex than just making oak tea out of your white dog.
Totally agree Chris!

Nice write-up Skow. Thanks for your time and effort.
Ga Flatwoods

[bellybuster]

I've played with nuking but have never seen it go cloudy like that...??

[FullySilenced]

Nor I... did get one report of clouding from Ireland... a couple years ago but that occurred for that person just once...

I think it came down to the chips being dirty once he started rinsing his chips or soaking them.. it went away... would have to go back and read...

IT could happen more and just not be reported but i bet if left on chips it will go away with a little time...

Happy Stillin

FS

[skow69]

I can hear thousands of voices saying, "Nuking never did that to mine." and you could well be right. I encourage you to try it again with your next batch. Keep a control jar aside for comparison. Take pictures and post them here. Help me understand where I went wrong. Replicate the procedure. It's what scientists do to prove each other wrong, or right.

[S-Cackalacky]

I've been nuking for a while now and the only time I had a problem with clouding was with some applewood chips. I'm thinking in that case it was possibly because the wood wasn't well seasoned and may have released some lignin into the product. That said, did you use sticks from the same source piece of wood for all three experiment samples?

One other comment - I've never considered the result of nuking to be a finished product. It seems to do a fine job of extracting the goodness from the wood, but it still needs some form of actual aging. I usually nuke for 2 or 3 cycles, strain out the chips, and put it in glass for at least a couple of months. I'll try to shake it and air it for a short period of time every couple of weeks or so. I found that I have good drinkable product after a couple of months. I draw it out of the aging jug into a bottle and dilute to 45 to 50 percent as I need it. I've found that the last of it out of the aging jug is far better than the first bottle I draw out.

I've thought about using one of those "Food Saver" vacuum machines with the quart jar adapter to serve the same purpose as the nuking, but never really had the money to buy one. It kinda makes sense that you wouldn't lose near as much ABV if you don't heat it up.

[FullySilenced]

@skow69 I am not sure what you would like for us to do try and duplicate your .... up and document it?

FS

[skow69]

Ya the sticks were all cut from a single barrel stave.

[skow69]

Sorry FS. You're OK. I was expecting more adamant pushback for questioning the accepted norm. Maybe I'm just being paranoid. It truly is a more tolerant HD. Haven't seen a serious gangbang for a long time.

[FullySilenced]

@skow69 We mods as a group are trying to move the forum in that direction... when i first posted the nuking thread it was quite different on HD than any of the other forums it was posted on.. But thanks to Tater, Husker and company... cooler heads prevailed and let it run..

If i have an answer regarding the clouding of your distillate i would try and help but I have never had that occur to me... and if i was a betting man I would say i have nuked more product than the average member here ... don't give up on it it has a place

Happy Stillin

FS

you can PM me anytime if i can assist sir

[skow69]

Thanks FS. I can see you know what I was reacting to. And congratulations, your efforts as mods are definitely having a noticeable effect. For my part, I will try to lose the paranoia and take the chip off my shoulder. Keep up the good work.

Skol,
skow

[Copper top]

Skow69 thanks for a great write up I think more time and trials are needed on this,
my own experiment is not quite As comparative as what you have carried out,

I have 4 1 gallon Demi johns filled with 55% spirit each with 35 oak sticks so they are all very similar
On one of them all I have been doing is attach a rubber bung with a copper pipe and plastic pipe connected , I suck on the end of the pipe and fold it to trap the vacuum , as I do this I notice air/ bubbles comming from the oak sticks .sometimes I leave it under vacuum and other times just carry out a few cycles and then fit a cork bung,
I have been doing this over the last few weeks every other day or so,
My experiments are still I'm the very early stages but I do sample each jar weekly and I'm delighted with the results I'm getting from the vacuum assisted one,
It has only been 4 weeks so I'm not in a position to post any conclusive results just yet, my garage is quite cool at around 2 deg c to about 10 deg c

Question ---The colour is looking good so I'm thinking of now removing the oak sticks or is this to soon ?

[drdale]

What are the bubbles coming from the oak when the vacuum is on? Air inside the wood? Alcohol inside the wood? Why the bubbles only form on the wood and not the glass or in the liquid?

[rad14701]

What are the bubbles coming from the oak when the vacuum is on? Air inside the wood? Alcohol inside the wood? Why the bubbles only form on the wood and not the glass or in the liquid?

Gases being drawn out of the wood...

[drdale]

Makes sense as it seems the bubbles are only coming out of the relatively new wood.

[teh721]

I wonder if nuking wood chips that have become saturated might be causing some kind of micro boiling in the wood pulp causing it to rupture and therefore cloud up?

I also color/flavor my stuff with chips and have actually been toying with the idea of using only a warm water bath with the mason lids loose to help promote movement through the chips and then with the subsequent cooling creating a vacuum seal that might pull everything back through. I've got 6 half gallon jars that just got 'chipped' this weekend, and may have to use one as a "sacrificial' test.

[papapro]

Guys: 12 years old whiskey has experienced many pressure changes look at this chart:
http://www.cnyweather.com/wxbarodetail. ... detail.php" onclick="window.open(this.href);return false;" rel="nofollow and this is only one year of aging,
the barrel when stays for 12 years has many small pressure changes.

there are few possibilitys I have used long time ago ultrasonic cleaner which removes all substances from
the cleaning object or I am thinking to use some kind of small speaker or small vibrator pump to create small pressure changes.

these options would give faster removal of carmelized sugars from roasted oak.

regards PapaPro