Lessons in Barrel Aging

[Patio29Dadio]

Acquired (all taxes paid) white dog bourbon and white rum from a friendly distiller to test different small barrels and entry proofs.  Five gallon and ten gallon new oak barrels from Barrel Mill with #3 char.  After four months in the 5 gallon at 60% ABV the rum seemed to have over-extracted... the funk was resolved, but the spirit has a more bitter, acrid and sharp finish and has taken on some of the barrel char... it does not have the long rum sweet finish I would expect.  Very little vanilla and toasted brown sugar notes that I would expect from brand new barrels.   Bourbon in 10 gallon for six months is starting to give the same.  It also entered at 60% ABV.   Nose is great except for a mild charcoal hint from the barrel char (same as rum).  Color is great.  Barrels are in a storage shed with good temp swings.   Both white spirits seemed perfect to me based on my experience with the un-aged variety.  

My question is related to my barrel-aging inexperience here.  I know people are going to make the point of "see, that is what you get trying to use small barrels!"  But either the over-extraction is extreme, I have some bad barrels, or I mistaking over-extraction with under-maturation.  At this point I am just going to let it keep aging and check it every 3 weeks or so.  But hoping someone can share some knowledge of aging/maturing evolution to help me diagnose what might be happening here.

[Silk City Distillers]

Couple points.

I think you'll find rum in used barrels is more characteristic of the typical flavor profile of an aged rum rather than in new barrels.  Color on the new barrels is fantastic, but like you say, the oak can be very forward, especially on a 5 gallon barrel.  I've tasted some nice rums that were aged in a mix of new and used oak that I thought were very good, so it's possible.  Likewise, probably doable in a larger format barrel, where you can better control extraction vs. maturation.

Which brings me to the next point, extraction vs maturation.  On a 5 gallon barrel, extraction will outpace maturation significantly.  10g is better.  15g is better than 10g.  25/30g better yet.  

If you must work with small barrels, consider cutting the time in oak, transferring to a tank, and finish maturation in glass or stainless (yes, maturation reactions will continue).  Realize there are age-statement implications.

[Jedd Haas]

13 hours ago, Patio29Dadio said:

it does not have the long rum sweet finish I would expect.  Very little vanilla and toasted brown sugar notes that I would expect from brand new barrels.  

Bear in mind that most mass-market rums have sugar added. That is why people think that rum should taste sweet, although most are unaware of the added sugar.

[twalshact]

I recently watched an ADI breakout session on oak barrels.  "The Extraction of Wood Compounds during Aging in Wood Barrels and in Contact with Wood Pieces"

The oak was tested and found very different from tree to tree from the same forest. From very little aging to fast aging. Could some of this play a part.

Black Swan has a aging chart for various size barrels.  https://www.blackswanbarrels.com/links-accolades/

Tim

Doc2.docx

[Patio29Dadio]

Jedd Hass - Thanks for the advice on the rum.  This is unaltered white rum distilled from 50% dark molasses and 50% cane sugar.  I have some left and there is a sweetness to the white rum that seems to be over-shadowed by the qualities of the aged version of itself.   

Silk City Distillers - Based on your comments, I am thinking I hit over-extraction on the small new oak barrel before I got enough maturation.  I like your idea of allowing it to sit outside of the barrel or in a used neutral barrel to see what happens.  This is a pre-distillery opening test, so I don't mind discarding the results as long as I learn something important. 

twalschact - Thanks for the reference.  I will check it out.  This gets to my concern that I have a bad batch of barrels.  However, the nose on these tests tell me that the barrel is full of the good stuff one would expect from well-kept American white oak. 

I am going with over-extraction at this point... however, I am just going to leave the bourbon in the 10G barrel and test it every month or so to see how it progresses.  I will pull a small bottle every test and label it for future reference. 

Thanks!

[bluefish_dist]

Also look at different suppliers.  For us we found some barrels offer quicker extraction than others.  Depending on how you do cuts and how long you want to age this can be good or bad.  

Second use is also much slower for extraction.   Gibbs brothers seem to be slower on the extraction and may be better suited than barrel mill barrels if you need more time for maturation. 

[RobertS]

Spirits made for unaged consumption are also going to be made a bit different than those for aging. There a number of unpleasant compounds that react during maturation to create complex and complimentary aromas and flavors. At this stage it is probably extraction that has not been balanced by time to mellow, but don't be surprised if your product comes out a bit simple/flat compared to aged whiskies and rums from the same distillery you bought from.

[Patio29Dadio]

On 7/17/2018 at 12:34 PM, RobertS said:

Spirits made for unaged consumption are also going to be made a bit different than those for aging. There a number of unpleasant compounds that react during maturation to create complex and complimentary aromas and flavors. At this stage it is probably extraction that has not been balanced by time to mellow, but don't be surprised if your product comes out a bit simple/flat compared to aged whiskies and rums from the same distillery you bought from.

Thanks.  This is my conclusion too.  After a month resting in a neutral barrel it is already much better.  I think I got full extraction without enough maturation time... the challenge with small barrels in striking that balance.  Once we are in business this will be fun... making a more funky/dirty spirit to go into 53G barrels, while keeping some cleaner to go in the smaller barrels.  However, it seems that to get the most out of the aging process for the small barrel product, there needs to be a finish rest in a neutral container.  That is what I think I know at this point... which is not nearly what I need to know!

[MDH]

Over-extraction simply tastes like too much of the oak characteristics. Hence, a highly aged product that is overextracted will taste very strongly of vanilla, wood, spices, caramel that one might associate from a Bourbon. However, astringency, bitterness and acrid taste exist in your spirit because it is simply underaged. Extraction does not equate to aging. It is only the very beginning of it. The components you have over-extracted now need to react with alcohol and other compounds in the spirit, and the most volatile fraction of spirit (Which even with a very effective head removal will always be present in newmake spirit) still needs to gradually be reduced through air movement throughout the barrel by varying forces (air movement in room, temperature swings, etc).

So simply transfer your overextracted spirit to some well used barrels and allow them to age there conventionally. If you can find a very large barrel (a hogshead or sherry-butt for example), fill it only 60% of the way to allow faster interaction with oxygen and reduction in highly volatile compounds.

[richard1]

Consistency.

 

I love the idea of barrels and it all sounds right BUT is it not the better way (for consistency) to rather use new charred staves with a 53G drum or similar.  In this way you know that you are putting in new and same quantities with every batch.

[Patio29Dadio]

Quote

However, astringency, bitterness and acrid taste exist in your spirit because it is simply underaged. Extraction does not equate to aging. It is only the very beginning of it.

Thanks MDH.  That makes sense.  It isn't that I am over extracted, just not aged enough (although my wife would say that I am plenty of both!  Ha!).  

This brings up a challenge in gauging when enough is enough in a small barrel.  I don't think I would have helped the situation leaving it in the new barrel any more time.  There was already a lot of wood... and the char was beginning to become an unwanted "smoke" note.  But the spirit was definitely not ready to bottle.  With the small new barrel it seems that a healthy time in an old neutral barrel before bottling is going to be required.  

[Silk City Distillers]

1 hour ago, Patio29Dadio said:

Thanks MDH.  That makes sense.  It isn't that I am over extracted, just not aged enough (although my wife would say that I am plenty of both!  Ha!).  

 This brings up a challenge in gauging when enough is enough in a small barrel.  I don't think I would have helped the situation leaving it in the new barrel any more time.  There was already a lot of wood... and the char was beginning to become an unwanted "smoke" note.  But the spirit was definitely not ready to bottle.  With the small new barrel it seems that a healthy time in an old neutral barrel before bottling is going to be required.  

This may have labeling implications.  For example, if you dump bourbon into used oak, the clock stops. At some point, you are going to wonder if it just makes more economic and operational sense to move to slightly larger barrels.

Economically, the price difference between 5g -> 10g -> 15g is minimal.  If you are dumping a 5g at the 6 month mark, and letting it sit for 6 more months, why not just age in a 10?  Likewise, dump a 10g at the 1 year mark and let it mellow for 6 months, why not just use a 15g?

 

 

[Julius]

19 hours ago, Silk City Distillers said:

This may have labeling implications.  For example, if you dump bourbon into used oak, the clock stops. At some point, you are going to wonder if it just makes more economic and operational sense to move to slightly larger barrels.

Economically, the price difference between 5g -> 10g -> 15g is minimal.  If you are dumping a 5g at the 6 month mark, and letting it sit for 6 more months, why not just age in a 10?  Likewise, dump a 10g at the 1 year mark and let it mellow for 6 months, why not just use a 15g?

 

 

And if you plan on leaving it in a 15gal for more than 2 years be prepared for 50%+ angel share. 

[Silk City Distillers]

If you were going to leave it sit for 2 years, why wouldn't you use something like a 25g or 30g?

 

[bluestar]

On 8/3/2018 at 11:01 PM, richard1 said:

Consistency.

 

I love the idea of barrels and it all sounds right BUT is it not the better way (for consistency) to rather use new charred staves with a 53G drum or similar.  In this way you know that you are putting in new and same quantities with every batch.

No, because then you lose the effect of transpiration. There are 3 effects of barrel storage: extraction, transpiration, and aging. All contribute. Yes, you might be able to reproduce all 3 but sophisticated technology.

[Thatch]

16 minutes ago, bluestar said:

No, because then you lose the effect of transpiration. There are 3 effects of barrel storage: extraction, transpiration, and aging. All contribute. Yes, you might be able to reproduce all 3 but sophisticated technology.

And what is the value of transpiration?  Is this filtering?  If it is, why do you believe it cannot be achieved with staves?  In an article attributed to your distillery (you?) https://www.chicagobourbon.org/2016/09/14/quincy-street-distillery-history-meets-science/ reference is made to UV treatment, have to tried it?  How about ultrasound and oxygen such as Terressentia?  If the effects of aging in India can accelerate the aging of spirits due to temperature swings not seen in Scotland then why not staves and Ultrasound or for that matter oak sawdust and Ultrasound?  Sorry if I hijacked the thread but this seems to be pertinent to aging and the initial question the OP posted.

[Patio29Dadio]

Quote

This may have labeling implications.  For example, if you dump bourbon into used oak, the clock stops. At some point, you are going to wonder if it just makes more economic and operational sense to move to slightly larger barrels.

Economically, the price difference between 5g -> 10g -> 15g is minimal.  If you are dumping a 5g at the 6 month mark, and letting it sit for 6 more months, why not just age in a 10?  Likewise, dump a 10g at the 1 year mark and let it mellow for 6 months, why not just use a 15g?

Exactly!

We will be open for production in about 4 months.  TIs are rolling now.  To start I will have a 100G system (scotch helmet and 4-plate whiskey column).  With quality mash conversion and fermentation, I would expect to fill a 10-gallon barrel with each finishing run.  I tested 5G and 10G barrels and had about the same result... after 4-6 months the spirit was giving off what I would consider full barrel extraction but without some of the pleasing finishing things that happen with a taste.  The neutral rest is fixing that.  There is no shortcuts to actually testing and failing and learning why.  I am embracing failure at this point, but it feels good with dots start connecting.

The label will say aged not less than 1 year.  It appears that 6 months in a new 10G and then moved into a used neutral barrel to finish in 6 months will work.  The idea is to have "small-barrel" whiskey product for sale in a year.   For rum, it will be aged not less than 6 months.   Now, after we have a supply of 10G filled, we will start filling some 30G and then some 53G barrels for longer-aged stuff that will be a different label... aged not less that 2 years (1 yr for rum).  Eventually we will be all 53G (and the bigger equipment will be installed by then).

Obviously this plan will come with a need to reformulate protocols as a longer- aged spirit should be funkier, tailsier and maybe with a bit of butyric (IMO) since that is the source of those nasties result in good molecules derived from full maturation. 

In the end we are all running a real business and need to generate revenue.   Waiting for 2+ years before I have aged whiskey to bottle and sell might help my purist ego, but not the business... as long as there is a method to get good tasting brown juice into a bottle after aging in a small barrel.   And so far so good... the rum and bourbon in the resting cask are getting better every day.  In fact, when the wife and I are thinking we want something to sip on the patio, I am drawn to thieving some from the resting casks instead of dipping into my extensive collection of bottled brown spirits.  That is a very good sign!

[bluefish_dist]

 

I would  also try some Gibbs barrels if you want a little slower extraction.  

[bluestar]

23 hours ago, Thatch said:

And what is the value of transpiration?  Is this filtering?  If it is, why do you believe it cannot be achieved with staves?  In an article attributed to your distillery (you?) https://www.chicagobourbon.org/2016/09/14/quincy-street-distillery-history-meets-science/ reference is made to UV treatment, have to tried it?  How about ultrasound and oxygen such as Terressentia?  If the effects of aging in India can accelerate the aging of spirits due to temperature swings not seen in Scotland then why not staves and Ultrasound or for that matter oak sawdust and Ultrasound?  Sorry if I hijacked the thread but this seems to be pertinent to aging and the initial question the OP posted.

Transpiration is the process of whiskey moving in and out of the wood, or even through the wood. This process occurs in a regular barrel by virtue of the osmotic pressure changing from the changing temperature and humidity on the outside of the stave relative to the inside for the whiskey-filled barrel. If you have free floating staves or wood inside the liquid, you don't have this effect. To some degree, you might try to artificially replicate this effect by pressurizing and de-pressuring the whiskey in the barrel; there is a US craft distillery who does this for their "fast aged" whiskey, although again, they have not accelerated aging, but transpiration and thus extraction.

Aging is aging, you don't accelerate by temperature swings, but elevated temperatures will increase the reactions of aging compared to lowered temperatures, although all the different chemical processes do NOT change their rates of reaction to the same degree with a change in temperature. In fact, some reactions can change by orders of magnitude with temperature, and others almost not at all! Many people unfamiliar with the science of barrel aging will confuse aging, extraction, and transpiration. The transpiration affects both extraction and "filtration", the latter in the case of charred barrels. It can also cause a concentration in the solutes with longer aging (so-called "angel share" effect). Hence, why using a sealed non-oak container with oak adjuncts inside is NOT the same as using an oak barrel as far as transpiration.

The UV treatment methods are currently patented. We have not tried them ourselves. This is an example of an expensive technology that could be used to do a rapid "aging", because it will increase the speed of some of the aging reactions without having to overly elevate the temperature. However, it will not necessarily be exactly the same result, because photo-induced chemistries will increase at rates different from those from changing temperature, and which reactions increase is different, so the result is different from long aging.

Sound and ultrasound can increase extraction. Ultrasound can maybe increase some chemical reactions (photoacoustic chemistry), although I have not seen evidence of a good result for this.

Oxygenation by itself is actually a potential problem, unless balanced with appropriate technologies to use the oxygen in reactions normally associated with aging, like esterification.

In any case, I am not arguing you can't throw all the technology plus the kitchen sink at the problem to get something comparable to longer aging in shorter time. You might well be able to, but it probably will be expensive to do, and may not taste exactly the same, and is not aging in any case, and the TTB won't let you call it that. Aging occurs, according to the TTB, in OAK BARRELS, and means length of time, legally. Period. And the flavor profile from long aging is complicated, and affected by many environmental factors, so replicating it with other technologies is a challenge.

In the end, you make your whiskey, you properly label it, you tell the consumer (hopefully) what you did, and they like or not and pay you accordingly!

FYI, I am a retired physicist who spent 40+ years studying photochemical-induced organic reactions, among other things, and so this colors my perspective.

[bluestar]

21 hours ago, bluefish_dist said:

 

I would  also try some Gibbs barrels if you want a little slower extraction.  

Generally, slower extraction with barrels made from oak with tighter grain. Northern oak (like from Minnesota) would be an example. Southern oak (like from Missouri) tends to have more porosity. So, my preference is to use large barrels from the south and small barrels from the north. YMMV.

[bluestar]

On 8/8/2018 at 12:02 PM, Julius said:

And if you plan on leaving it in a 15gal for more than 2 years be prepared for 50%+ angel share. 

We have done 5g for 2 years, twice now. about 60% loss as angel's share. This is for a tight grain oak (Minnesota). For similar oak, we don't see anywhere near that much loss in a 15g in 2 years, closer to 30%. YMMV

[Julius]

1 hour ago, bluestar said:

We have done 5g for 2 years, twice now. about 60% loss as angel's share. This is for a tight grain oak (Minnesota). For similar oak, we don't see anywhere near that much loss in a 15g in 2 years, closer to 30%. YMMV

Our dry mountain climate does not like small barrels. Maybe a more humid climate or supplemental humidification in storage would be more suitable for small barrels. 

We have harvested 15, 15gallon barrels, each was 50%-70% angel share after 30 months. Harvesting 8, 30 gallon barrels saw 35%-55% angel share at 36 months. We are in a very dry climate. YMMV

 

We have had great luck with the Gibbs Brothers 3 gallon barrels. ~10% angel share annually

[jeffw]

On 8/8/2018 at 4:58 PM, Patio29Dadio said:

Exactly!

We will be open for production in about 4 months.  TIs are rolling now.  To start I will have a 100G system (scotch helmet and 4-plate whiskey column).  With quality mash conversion and fermentation, I would expect to fill a 10-gallon barrel with each finishing run.  I tested 5G and 10G barrels and had about the same result... after 4-6 months the spirit was giving off what I would consider full barrel extraction but without some of the pleasing finishing things that happen with a taste.  The neutral rest is fixing that.  There is no shortcuts to actually testing and failing and learning why.  I am embracing failure at this point, but it feels good with dots start connecting.

The label will say aged not less than 1 year.  It appears that 6 months in a new 10G and then moved into a used neutral barrel to finish in 6 months will work.  The idea is to have "small-barrel" whiskey product for sale in a year.   For rum, it will be aged not less than 6 months.   Now, after we have a supply of 10G filled, we will start filling some 30G and then some 53G barrels for longer-aged stuff that will be a different label... aged not less that 2 years (1 yr for rum).  Eventually we will be all 53G (and the bigger equipment will be installed by then).

Obviously this plan will come with a need to reformulate protocols as a longer- aged spirit should be funkier, tailsier and maybe with a bit of butyric (IMO) since that is the source of those nasties result in good molecules derived from full maturation. 

In the end we are all running a real business and need to generate revenue.   Waiting for 2+ years before I have aged whiskey to bottle and sell might help my purist ego, but not the business... as long as there is a method to get good tasting brown juice into a bottle after aging in a small barrel.   And so far so good... the rum and bourbon in the resting cask are getting better every day.  In fact, when the wife and I are thinking we want something to sip on the patio, I am drawn to thieving some from the resting casks instead of dipping into my extensive collection of bottled brown spirits.  That is a very good sign!

Just to be clear.  Bourbon put into used cooperage (even after aged in new cooperage) is no longer bourbon.  If bourbon touches anything other than new cooperage it is now whiskey or a distilled spirits specialty (per frustrating conversations with the TTB).

[Silk City Distillers]

We have two approved bourbon colas that explicitly state finishing in used casks.  Both included discussions with labeling for clarifications.

One is a bourbon finished in an IPA secondary fermentation cask - that took a little bit more discussion.  The other is a rum cask that was previously a new bourbon cask.

 

[Patio29Dadio]

Quote

Just to be clear.  Bourbon put into used cooperage (even after aged in new cooperage) is no longer bourbon.  If bourbon touches anything other than new cooperage it is now whiskey or a distilled spirits specialty (per frustrating conversations with the TTB).

I don't believe this to be the case.  As I understand you can use a finishing barrel after meeting the age requirement (based on your approved product specification) in the charred new oak container.   A good example is Angels Envy... finished in port wine casks.