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Wednesday, July 24, 2013

Whiskey #200: The Rye Storm (Part 1)

I made some rye.  Correction, I barrel aged some rye spirit.  I named it The Rye Storm.  Over the past six months, I've been indulging in this experiment in the background, far from the daily routine.

Here's a video I threw together of that recaps some of the post below:

A Barrel!

My brother-in-law, Andrew, and his wife, Leslie, bought me a two-liter pre-charred barrel for Hanukkah last December.  (Thank you, guys!!!!) Within minutes of holding the barrel in my hands, I knew what I wanted to do with it: two things, equally important and intertwined.  Aging rye spirit would be the first part.

I wanted to make sure the spirit I'd use had a very high rye mashbill, since that's the sort of stuff I like to drink.  Having tried Corsair's Wry Moon (46% ABV) on a couple of previous occasions, I knew it was the only rye white dog that I liked on its own.  Of course, for Wry Moon, Corsair uses malted rye rather than the unmalted rye utilized by most rye producers.  That would definitely affect the flavor.  They also use a tiny portion of Chocolate (or roasted) malted rye, which really does give the spirit a light cocoa note.  This wasn't going to be a harmless comfy rye, it was going to be a little odd.


The barrel itself held some challenges.  I didn't know what the char level was, which is a complication since that would directly affect the maturation and final product.  Also, I wasn't sure how well coopered it was.  In a related issue: Our condo stays very warm. During the day when no one's home (and the A/C isn't running) there isn't a cool spot in the entire joint.  How much spirit would I lose to the angels?

Despite those quirks and despite the fact I'd never done this before, I went ahead and set lofty goals.  I wanted to end up with something approximate to a three-year-old rye; some oak, but not too much oak.  I still wanted the white dog to bark through his house.  Since the barrel's surface area is so small, leading to a lot of spirit/oak contact, maturation would happen 5x-10x faster than a normal bourbon barrel -- so said the instructions.  So, I thought it would take 3 to 4 months.  I'd rotate the barrel every week, then taste it every four weeks.  The Wry Moon bottles would work perfectly for bottling the result since they have a very tight cork.

On January 31, I filled the barrel with the Wry Moon.  I was left a few ounces of the spirit from the third bottle that I could compare and contrast with the developing experiment.  A dark corner was found where the barrel could be tucked away.  I figured that after three or four months, there would still be 1.5 liters left, enough to fill two bottles.  A 22% loss to the angels sounded like a comfortable overestimation to be safe.


From my notebook:

At 36 days - 12.5% of the volume has been lost. No color, remains very clear. No change on the nose. Slightly easier to drink, perhaps a wider variety of notes on the palate.

At 74 days - 24% of volume lost, less than 1400mL already. Color remains the same. Decision made to hold off on nosing and tasting for a couple weeks.

At 91 days (3 months) - 31.1% of volume lost.  The spirit has begun to take on some color. The nose has been considerably softened. First hints of oak vanilla and honey. Big hot chocolate finish, a little more sugary on the palate. Sudden realization: The liquid is evaporating much faster than the alcohol, this is considerably hotter than the original 46% ABV.

At 122 days (4 months) - 42.2% of volume lost. Liquid evaporating more quickly as the weather gets warmer. Color looks good, like a light bourbon. Still spirity, but a little floral with some nice baking spices on the nose.  The palate remains similar to before, though getting smoother and thicker.  Adding water to sample didn't result in any changes.  Realization: Will need to age as long as possible, but not so long that the rye will turn into a poisonous thimbleful.

At 164 days (about 5 1/2 months) - 61.5% of volume lost.  Just enough to fill one bottle.

The Rye Storm has arisen.  In the next post, I'll talk about the brown stuff in the bottle.


  1. Michael, you may be a writer, but there's a scientist lurking not far beneath the surface there! I love the experimental approach and the careful data collection! I did a quick analysis of your evaporation data. It seems that your whisky gets lost at a remarkably linear rate, of 11% of the original volume per month, or 220ml/month. In 9 months it would all be gone! In fact, there was a slight acceleration after the first 2.5 months, with a 10% rate for the first months and 12.5% thereafter. This change could be due to the change of seasons, or to the differential evaporation rates of the whisky in contact with the barrel and of the surface in contact with the air - or to the loss due to your sampling!

    The main factor in the high evaporation rate is the size of the barrel. A simple model would be to assume that the evaporation volume is proportional to the contact surface, i.e. the area of the barrel. Some straightforward math shows that the evaporation rate p is proportional to the inverse cubic root of the volume V, or p = k/V^(1/3). So, if next to your barrel you had an identical one but of 250L capacity, the large one would have only 1/5th of the evaporation rate of the small one, or 2%/month.

    24% per year is still a hell of an angels' share, which I don't think that Kentucky would be happy with. My guess is that the barrel itself must be very porous and not of industrial quality.

    Another interesting aspect is that in a dry climate like Southern CA most evaporation should be water, but in that case the evaporation rate would slow down over time as the spirit loses water. And then that bottle of yours would be 100% alcohol! So obviously lots of alcohol must also evaporate into your kitchen.

    There is an inescapable conclusion to this careful analysis: your wife is slowly draining your barrel when nobody is watching. Hey, you're welcome!

    1. An amazing conclusion! Kristen said, "Yep, you caught me." We had a great laugh about that this morning.

      I do have a bit of a math head and took lots of measurements and notes along the way. You're right about the evaporation speeding up a little bit. Also, I subtracted my sample volumes before each calculation because I'm no angel. Thanks for the evaporation/surface contact formula. I was wondering how much slower it would have been in a standard barrel size. I'm also leaning towards the possibility that there are issues with the structure of my little barrel.

      The water evaporation issue was another reason why I had to bottle the rye when I did. I was concerned about it heading into dangerous post-Stagg ABV levels.

      Anyone know where I can get a cheap hydrometer? :)

    2. For context, Kavalan loses 10% per year, which is considered *extremely* high for an angel's share. Even Caribbean rum only loses 6-8% per year. Surface area is probably the biggest consideration, but the wood may also be a big factor. They may have used more porous oak, which would also increase evaporation.

    3. I just realized that in my calculations I did no take into account the thickness of the barrel. A rough model is that by doubling the thickness you cut the evaporation rate in half. So, say, if the thickness of the barrel is proportional to the length of the staves, then my formula changes to p = k/V(-2/3), which would make the evaporation rate in a 250L barrel 5%/year instead of 24%/year. This is a lot more reasonable.

      A couple other thoughts prompted by your experiment:
      - As the liquid goes down, the surface of contact between liquid and barrel also goes down. Since the rate of loss does not decrease over time, this suggests that there's a lot of evaporation at the barrel's surface *above* the liquid line.
      - As a consequence, these vapors may be lost if you mess too much with the barrel - or if the bung is large. This could also explain the accelerated evaporation in the last three months
      - Since there's such a free exchange between the barrel and the outside, is oxidation of the whisky inside a concern?
      - As an experiment, what if you kept the barrel topped off? What would the evaporation rate be then? And how would the taste be affected?

    4. I tried to mess with the barrel as little as possible. I rotate(d) it once a week to make sure there's good contact with all of the surface and I only pulled the bung stopper three times (very briefly) in those 164 days to sample from the spigot. The bung stopper felt pretty snug, but I bought some new ones for these successive tries.

      The flavor and smell characteristics showed little sign of oxidation, but there would be opportunity for oxidation (or at least exposure to the outside environment) each time I pulled that stopper. If I do wind up doing a third try, I'd consider keeping the barrel topped off but I'll need to find a cheaper whisk(e)y/spirit to keep things refilled.

    5. @Jordan - The room where I'd kept the rye does get a bit warm, especially in Summer. It'll get up to 82-84 even with the A/C going in Summer. I knew it would get warmer in there as time went on, but didn't expect needing to keep the maturation going for so long. The second fill experiment is in a darker spot that's about 8-12 degrees cooler. I'm wondering about the porousness of the oak too because my condo is neither the Caribbean nor Taiwan, sadly.

    6. If there's vapor exchange, then air is coming in to fill the space, so there's definitely room for oxidation. Additionally, as it was fairly warm, oxidation will occur more quickly. The rule of thumb for chemical reactions is that they will go 2x faster for every 10º C that you raise the temperature. Again, this is part of why spirits tend to mature faster in warm places like Kentucky, the Caribbean, India, or Taiwan. As a side note, this is also why I sometimes have to adjust my reaction conditions if I'm following a procedure from a lab in India - some of their labs aren't air conditioned, so their "room temperature" is about 10º warmer than mine.

    7. It'll be interesting to see the evaporation rate on the stuff currently in the barrel. Storage is in a spot that's about 5 degrees Celsius cooler. The spigot and bung stopper are a better fit too. I'd rather not share THAT much with those damned angels.

  2. There's a $9 hydrometer on Amazon.

    I'd check your wife's legs and pockets for a hidden "dog." Those little copper tubes were notorious for stealing drams from casks in many Scotch distilleries.

    If you don't notice any wet spots on the mini-barrel, I'd say it's pretty watertight. Another blogger got about three fills out of one before it really started leaking. For the second fill, I'd recommend putting a cheap and crappy blend in there to see if it improves since you've already seasoned the inside.

    1. By the way, it's amazing how three bottles of new make ended up as one bottle due to angel's share. It makes me wonder how many gallons the distilleries produce that doesn't end up in the bottle.

      Incidentally, while laughing at Florin's suggestion that your wife was draining the barrel, I wondered what that whisky loss should be called...

    2. If The Devil's Cut is what the barrel absorbs and The Angel's Share is what evaporates, the anything nabbed by a spouse may be called Commission.

      Or the Patient Partner's Portion if alliteration is preferred.

      There was one small damp area near one of the barrel heads at first, but that may have been due to some spillage, it doesn't appear to be damp anymore. Three fills on one of those is impressive, I'm doubtful mine will hold up after a couple months of a second fill. The barrel makers claim that it should be fine for 2 or 3 years, but there's no warranty for that.

  3. Eric, a watertight barrel will not allow the *liquid* to seep out. However, depending on how porous the wood is, more or less *evaporated* water and alcohol will be lost, i.e. in gaseous form. If Michael gets another such barrel as a present, he could age whisky in both of them in parallel, and have one of them wrapped in plastic to stop/slow evaporation. A couple more experiments like this and he's ready to buy his pot still.

    1. I wonder why I was thinking the barrel will start seeping out liquid. I might be thinking about how the barrel will lose watertight-ness after you've filled it enough times (i.e. the wood becomes soggy).

    2. Good ideas all around, especially the pot still! I did consider wrapping this current fill up in plastic. Maybe for a third fill or a barrel to barrel comparison.

      I am curious to see how long the barrel holds up. If the wood is very porous and thin, I do wonder at what point the barrel structure will become compromised.