Effect of sunlight, air, and temp on open bourbons

[Harry in WashDC]

Several threads from 2014-17 contained discussions of: Do you decant to smaller bottles?  Do you keep your bunker in the dark?  What happens if you leave a bottle in the back window of your car for a year? (I made that one up.) 

 

Here's a link to an article on Breaking Bourbon discussing the results of their 24 month experiment with - bottles of WSR (because it is SO fair to middling) in the dark compared to bottles in the Sun compared to bottles in a fridge AND how those bottles tasted after 6 months, a year and two years.  Reading it made me glad my car trunk doesn't have a clear lid AND that the windows are tinted.  Plus, I don't keep open (i.e., half-empty) bottles in the trunk.  Leakage, you know.

 

http://www.breakingbourbon.com/bourbon-storage-experiment.html

 

Reading it also made me thirsty.  Hence, my handle of AAA "10" is taking a real hit tonight.

 

Edit -- HECK, I don't keep open bottles in my bunker, either.  HECK, the article has a chart at its end which, if I'd a seen it, would obviate the need to read the whole thing.  Thoughts?

 

Edit 2 - They started their experiment about the time we were thrashing each other about storage of, and changes in, open bottles.  Do you think . . .

Edited March 14, 2018 by Harry in WashDC

[JCwhammie]

That’s an interesting experiment.  I’m surprised with all the stuff I’ve read from Breaking Bourbon that I’ve not seen it before. Thanks for posting it, Harry.

[Mako254]

The fellows at BB do a great job IMO. 

 

I dont have many bottles that make it past 6 months. 

 

 

[jvd99]

What about ambient sunlight?  There are lots of SBers who've bought duties that were probably sitting on the shelf for 10 or 15 years, not in direct sunlight, but obviously illuminated to certain degree by ambient or indirect  sunlight.  It doesn't seem like that would make a huge difference on the contents of the bottle (assuming clear glass of course)

Edited March 14, 2018 by jvd99

[FacePlant]

I would concur with the article findings. Nothing scientific, but my samples keep in the dark (no direct sunlight) and in a constant temperature environment keep indefinitely. Cork excluded since some are toast on 3yrs others longer and synthetic the longest.

But hey, what do I know?

[Richnimrod]

Yeah, I saw that before and it confirmed my previous suspicion that the only real issue with long-term Bourbon storage is sunlight.    Well, that; and good tight seals. 

I doubt indirect (reflected) sunlight would have much effect; but, possibly not zero.

An interesting question, not investigated by BB would be: other types of direct light, such as fluorescent vs incandescent, etc.

[GeeTen]

15 minutes ago, Richnimrod said:

Yeah, I saw that before and it confirmed my previous suspicion that the only real issue with long-term Bourbon storage is sunlight.    Well, that; and good tight seals. 

I doubt indirect (reflected) sunlight would have much effect; but, possibly not zero.

An interesting question, not investigated by BB would be: other types of direct light, such as fluorescent vs incandescent, etc.

 

Good grief, Charlie Brown - we ARE bourbon nerds, eh?  

 

[Enoch]

While not scientific, I found a small liquor store in GA that had five liter bottles of 1980s Kentucky Tavern in the window. As they were cheap I decided to get all 5 of them even though the labels were bleached out from years in the sun. When I went to pay the clerk said she had several in the back so I agreed to buy them also. Their labels were not bleached out. When I got home the bleached ones were undrinkable...almost a gasoline taste. The ones from the back (unbleached) were quite tasty even though it was apparent they were the same age and identical. After tasting I had to pour out all  the window (bleached) ones. So I guess sunlight does affect taste. My wife came up with a new rule: Buy one and taste it in the parking lot. If good, go back in and buy the rest.

[Richnimrod]

58 minutes ago, Enoch said:

While not scientific, I found a small liquor store in GA that had five liter bottles of 1980s Kentucky Tavern in the window. As they were cheap I decided to get all 5 of them even though the labels were bleached out from years in the sun. When I went to pay the clerk said she had several in the back so I agreed to buy them also. Their labels were not bleached out. When I got home the bleached ones were undrinkable...almost a gasoline taste. The ones from the back (unbleached) were quite tasty even though it was apparent they were the same age and identical. After tasting I had to pour out all  the window (bleached) ones. So I guess sunlight does affect taste. My wife came up with a new rule: Buy one and taste it in the parking lot. If good, go back in and buy the rest.

Yer Wife?   A Pretty Shmart Cookie!!!

[flahute]

I've linked to this article numerous times in all of those discussions we've had. It's very good info.

The direct sunlight results are so stark that it kind of overshadows the other results.

What the results do tell us is that the more air in the bottle, the more it's possible for the whiskey to change over longer periods of time.

As their conclusions state though the change is not as much as we think.

[Dango]

12 hours ago, GeeTen said:

 

Good grief, Charlie Brown - we ARE bourbon nerds, eh?  

 

I believe we are, New name should be bourbongeeks.com instead of straight bourbon. I do think light of all sorts has an effect on many things if not all things. 

[WhiskeyBlender]

20 hours ago, flahute said:

I've linked to this article numerous times in all of those discussions we've had. It's very good info.

The direct sunlight results are so stark that it kind of overshadows the other results.

What the results do tell us is that the more air in the bottle, the more it's possible for the whiskey to change over longer periods of time.

As their conclusions state though the change is not as much as we think.

I've done some of my own experimentation with light for certain classes I teach, where I'll keep split a bottle of bourbon, and keep half of it in, the "control" sample, in a dark, cool environment. I'll put the other half in a window in direct sunlight. I'll taste both the control and the bourbon exposed to the sunlight every few days, and at least once a week. It is amazing to see just how quickly the bourbon that is left in the sunlight degrades. 

[Kpiz]

They did a nice job with this experiment, and I appreciate their dedication to science and bourbon geeks. The only thing I wish they had done is to have a fourth storage condition that was warm (well above room temp) and dark (out of direct sunlight). While the experiment is instructive in that it shows us not to store our bottles in direct sunlight, it doesn't show why. Does UV light actually affect taste, or is it mostly just the resulting warmth that catalyzes the reaction between the spirit and the air? If this hypothetical warm+dark storage had similarly negative effects as storing in direct sunlight, that would also affect where I'm keeping my bourbon.

 

I think they sought to determine the effect of temperature on taste by comparing the refrigerator sample to the closet (room temp) samples but both temperatures may have been sufficiently low as to limit the reaction between the spirit and the air in the bottle. The amber glass vs clear glass was also interesting but again, the two bottles garnered similar tasting notes (they state that "Interestingly, the amber bottle stored in direct sunlight fared much better than the clear bottles..." but this is not supported by their notes or the graph, at least not when comparing the amber bottle to the full clear bottle - I don't think comparing the full amber to the less-than-full clear bottles is very telling).

[smokinjoe]

I’m going to hazard to guess that temp alone does not negatively affect the taste of bourbon for no other reason that bourbon spends a great deal of its life in scalding 100+ degree temps while aging in rickhouses.  My guess, is UV could cause a lot of stuff to happen to the liquid, though.

 

Smokinjoe

Executive Director

Non-Believers of Bottle Airtime of America League

[WhiskeyBlender]

1 hour ago, Kpiz said:

They did a nice job with this experiment, and I appreciate their dedication to science and bourbon geeks. The only thing I wish they had done is to have a fourth storage condition that was warm (well above room temp) and dark (out of direct sunlight). While the experiment is instructive in that it shows us not to store our bottles in direct sunlight, it doesn't show why. Does UV light actually affect taste, or is it mostly just the resulting warmth that catalyzes the reaction between the spirit and the air? If this hypothetical warm+dark storage had similarly negative effects as storing in direct sunlight, that would also affect where I'm keeping my bourbon.

 

I think they sought to determine the effect of temperature on taste by comparing the refrigerator sample to the closet (room temp) samples but both temperatures may have been sufficiently low as to limit the reaction between the spirit and the air in the bottle. The amber glass vs clear glass was also interesting but again, the two bottles garnered similar tasting notes (they state that "Interestingly, the amber bottle stored in direct sunlight fared much better than the clear bottles..." but this is not supported by their notes or the graph, at least not when comparing the amber bottle to the full clear bottle - I don't think comparing the full amber to the less-than-full clear bottles is very telling).

Agreed, that would have really helped to round out the experiment. Hopefully someone is going to do this, if it hasn't been done already. 

[Paddy]

42 minutes ago, smokinjoe said:

I’m going to hazard to guess that temp alone does not negatively affect the taste of bourbon for no other reason that bourbon spends a great deal of its life in scalding 100+ degree temps while aging in rickhouses.  My guess, is UV could cause a lot of stuff to happen to the liquid, though.

 

Smokinjoe

Executive Director

Non-Believers of Bottle Airtime of America League

^^^This!

 

Plus, we all should know that heat and corks don't play well, together.  Any heat induced cork shrinkage/degradation is going to allow air to alter the product in the bottle, whatever it is...

[mcspin]

I just started to drink whiskey a couple years ago. At the time I developed this interest, I found a pint of whiskey I had on my wedding day, 33 years prior. It was about 1/2 full and had not be opened since. It had been in a liquor cabinet (in the dark at room temp) and not taken out at all. I decided to try tasting it, hoping it hadn't somehow become poisonous.  Amazingly it tasted almost identical to what I would have expected from a new bottle.  It was a cheap Kessler, so it wasn't very good to begin with, but hadn't gotten any worse.  When I saw this thread, I figured it would add some evidence that the right storage means a lot. 

 

[EarthQuake]

I've got a similar story. On Christmas my friend was visiting her parents and she found a bottle of Old Overholt and sent me a photo. It turned out it was circa 69-79', and was about half full. It had been opened by her aunt years (probably decades) ago who doesn't drink, but she had it for guests. After the holidays my friend sent me the remains of the bottle (about 1/4 full at that point). It tastes f'ing fantastic. It's an 8 year age stated rye distilled in PA. It tastes a lot better than the current Beam Old Overholt.

 

I don't know how it was stored, or how long it has been open. It has a dark brown bottle so maybe that saved it from UV damage? It seems like air time has helped if anything, as the whiskey has opened up with all sorts of complex flavors. But, I don't have a fresh bottle from the era to try it against, so that is mere speculation. I expected it to be flat and taste off in some way but it doesn't. Of course, it's possible that a fresh bottle from the same era would be even better, and the air time has only degraded what was once a phenomenal whiskey. Impossible to say for sure.

 

At the end of the day this is just an anecdote, but it was interesting. I wrote a post about it a few months back if anyone is interested:

 

 

Edited March 31, 2018 by EarthQuake

[MyBrainOnWhiskey]

Very interesting and helpful findings from Breaking Bourbon.  Good to know that my storage practices are validated.  I keep all my bottles in a dark, temperature controlled space (around 72 degrees fahrenheit).  As I am not a collector, they don't stay there for a terribly long time.  However, I recently started a practice of keeping samples of the bottles I most enjoy.  These samples are stored in 2 oz. amber Boston round glass bottles that I will likely keep for years before consuming.  I do this for two reasons: 1) to compare old batches to future batches of my favorite bourbon and whisky, 2) to reduce oxidation of small samples that would otherwise degrade over time if they were left in the original 750ml bottle.  Based on the results of the Breaking Bourbon experiment I should probably transfer these 2 oz. samples to a refrigerator, but their current location in a dark, 72 degree space is probably good enough.    

Edited April 1, 2018 by MyBrainOnWhiskey