Blending time for vodka? Who does this and why?

[FijiSpirits]

One of the processes That was done before I started at this distillery was they would blend the water and alcohol together and let it “blend” for 3-4 days before moving forward with follow on steps.  I’ve not heard of this before nor have I done it.  

 

I do note that my spirit will oxidize and change for a week or two before it settles down, which has vexed me, but I’ve not noticed a difference attributable to blending time.   Maybe it’s happening and I don’t know it. 

 

Ive not seen the difference between the following :

 

1-  let spirit sit for a week then blend

2- blend spirit and let sit for a week. 

 

So question is... is there value to mixing to proof and letting it “blend” for a few days before bottling?  What’s the Science?

[FijiSpirits]

Is it a sign that I can’t find information on this?

[meerkat]

It's probably not fully on-topic, but the only relevant feedback that I have had from users of my blending software is that some time is required between the physical blending process and when it is possible to get an accurate and stable proof reading.  The most plausible reason I have heard for this is that micro-bubbles of air are entrained into the spirit during mixing and affect the spirit density, and these bubbles take some time to escape.  The typical duration given for this "settling" period is 12 to 24 hours.  Nobody has ever suggested to me that 3-4 days are required and I suspect that this bubble-removal process is not what you are asking about.

[bluefish_dist]

I found it did take a day or so for the proof to stabilize, so I would always add water, then let it set a day before checking and adjusting.  I have heard others discuss not adding all the water at once for better flavor.  Ie take a few days to add it all.  Never tried it myself.  

[HedgeBird]

Mixing alcohol and water also produces an exothermic reaction that produces heat and can change the actual volume.  Waiting a day for these variables to subside can make it easier to take proof readings.  Less of an issue if doing things by weight and not volume but could still mess with your temperature correction when taking a proof reading.

There are also many believers in letting fresh distilled spirits sit open to the air for a few days.  (I think the idea being the more volatile, less tasty elements will evaporate first giving you a better product)  Personally I don't feel this is necessary if your doing good cuts..

Seems like your predecessor was possibly combing these two practices into one step..

[FijiSpirits]

Well. Heres the weird part.  Alcohol didn’t need proofed for the process and it was bulk spirits that had been manufactured months prior. 

 

It it makes sense to me on both counts so I’ll assume that’s what was happening. 

 

Now that you mention the volume change thing, they make a pretty big deal of it round here and are sure to subtract 5% from all blending calculations for that reaction. 

 

Ill have have to do an experiment where I take the 93% down to 25% and see what the actual reduction in final volume is. 

 

Anyone do this?  5%?

[meerkat]

A safety factor of 5% is excessive.  Using the TTB tables or software like AlcoDens you can do these calculations exactly without creeping up on the final answer with these large safety factors.

Even if you totally disregard the shrinkage on mixing in your calculations when proofing down from 93 to 25 abv your volume would be out by only 1.8 %, but of course your proof would be wrong too.

If it is the temperature change that you are worried about, you need a temperature swing of around 100 F to get a 5% change.

There is a free trial version of AlcoDens available.  Please give it a try and I am sure you will save yourself a lot of time and frustration.

[adamOVD]

Do you filter? I filter around 85 proof so it sits almost at bottle proof for at least a day or two at pretty close final proof anyways. I feel a bit of aging in an atmosphere with some oxygen available is good for any high alcohol liquids. Obviously whiskey in a barrel does. Even strong beers and wines can benefit from being cellered for a while.

Also alcodense is a great tool. I use it every day many times.

[FijiSpirits]

I want to play with alcodens. Have to get the pc set up for it tho. 

 

For tax tax purposes here in Fiji everything between 15-57% is taxed the same amount per liter.  Due to the difficulty we have with proofing most of it is done by calculations and tasting. As imperfect as that may be it is good enough for our purposes right now. Moving forward to export we have other plans. 

 

I agree that resting product is beneficial to stabilizing product.   I would love to play with some ultrasonic or other procedures to shorten the time to stability.