# What is your AC cellar humidity?



## jsbeckton (Sep 18, 2016)

So I built a small ~30sqft foamboard insulated cellar this summer. I have been cooling it with a 5000btu window AC unit and its holding temp pretty well so the unit doesn't run too much. My ambient basement temp is about 76F and I have a dehumidifier that keeps it about 50%. I have the cellar set at about 60F and its pretty steady at about 45% humidity. 

Not sure what the humidity will be at in the winter but I doubt the unit will run much at my basement ambient will prob be about 60F.

So, anyone else have any long term experience keeping wine at 45-50% humidity? Is this good enough or do I need to be thinking about a humidifier?


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## Johnd (Sep 18, 2016)

jsbeckton said:


> So I built a small ~30sqft foamboard insulated cellar this summer. I have been cooling it with a 5000btu window AC unit and its holding temp pretty well so the unit doesn't run too much. My ambient basement temp is about 76F and I have a dehumidifier that keeps it about 50%. I have the cellar set at about 60F and its pretty steady at about 45% humidity.
> 
> Not sure what the humidity will be at in the winter but I doubt the unit will run much at my basement ambient will prob be about 60F.
> 
> So, anyone else have any long term experience keeping wine at 45-50% humidity? Is this good enough or do I need to be thinking about a humidifier?



Mine stays at 70-73% without much fluctuation. "They" say that optimum humidity is 65-75%, but I don't know how big a deal it really is. You could set a humidity tray in there if you're really concerned. Bet it'll go up in the winter when the unit runs less and isn't removing so much humidity as it cools.


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## jsbeckton (Sep 20, 2016)

Yeah, it shouldn't run at all most of the winter. Out of curiosity I put the sensor in my refrigerator and it was 1% humidity. I think I will be fine at ~50%.


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## AZMDTed (Sep 20, 2016)

With an AC unit in my room the humidity stays at 43%, when I use an ultrasonic humidifier set at 60% the humidity stays at 54%. I could go higher but I don't see a need to. My research of the literature found that there's no definitive info on minimum humidity levels.


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## Johnd (Sep 20, 2016)

AZMDTed said:


> My research of the literature found that there's no definitive info on minimum humidity levels.



If you dig around a bit more, you'll find the vast majority of recommendations put humidity parameters in the above 60%, below 75% range. Most of the concern is centered around long term storage and cork integrity. If you're really storing wines long term, I suppose it could become a problem. I doubt anything in my cellar would ever sit long enough for a cork to dry out from low humidity. Personally, I'm more worried about it getting too high and causing mold / mildew problems.


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## ibglowin (Sep 20, 2016)

I live in the desert southwest and use a window AC unit for cooling during our short but sometimes warm Summers. Nothing of course during the Winter months as the temps stay 55 degrees with the heat mostly shut off. My humidity bounces from a high in the 50% range during our monsoon season to down in the low 30% range when things are really dry outside. I have not seen any issues with cork breakage with any of my wines I have made all the way back to 2009 using agglomerated or 1+1 corks. A few older commercial wines that I have stored under the same conditions that use a 100% all natural (really expensive) cork have broken off at times when using my table top cork screw opener.


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## stickman (Sep 20, 2016)

I'm using a through the wall Vintage Keeper cooling unit, now 14yrs old, and the humidity stays around 70%. When I was using barrels, the humidity made a noticeable difference in evaporation rate, but I agree as far as bottled wine goes, the humidity would only benefit very long duration aging.


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## AZMDTed (Sep 21, 2016)

Johnd said:


> If you dig around a bit more, you'll find the vast majority of recommendations put humidity parameters in the above 60%, below 75% range. Most of the concern is centered around long term storage and cork integrity. If you're really storing wines long term, I suppose it could become a problem. I doubt anything in my cellar would ever sit long enough for a cork to dry out from low humidity. Personally, I'm more worried about it getting too high and causing mold / mildew problems.



I agree that the vast majority of recommendations are as you say, but from what I've been able to find those recommendations seem to be based on the traditional cellar conditions in Europe rather than any studies on the actual effect of humidity.


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## AZMDTed (Sep 21, 2016)

stickman said:


> I'm using a through the wall Vintage Keeper cooling unit, now 14yrs old, and the humidity stays around 70%. When I was using barrels, the humidity made a noticeable difference in evaporation rate, but I agree as far as bottled wine goes, the humidity would only benefit very long duration aging.



You're right about humidity and the evaporation rate, that's a good point. There's an interesting article about that which seems to say that below 74% humidity the evaporation is mostly water resulting in higher ethanol content in the wine as well as potentially aromas. Above 74% and you decrease the ethanol in the wine. 

http://www.practicalwinery.com/janfeb91/wineevap.htm


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## FTC Wines (Sep 21, 2016)

Our 10X12 wine room stays at 66* year round, in Fl, with humidity staying in the 54-60% range. After almost 4 years we see NO problems with corks or aging. Roy


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## Johnd (Sep 21, 2016)

AZMDTed said:


> I agree that the vast majority of recommendations are as you say, but from what I've been able to find those recommendations seem to be based on the traditional cellar conditions in Europe rather than any studies on the actual effect of humidity.



Yep, there are pretty wide recommendations for humidity range, again, long term cork health seems to be the driver there. I use real cork in my wines, but still not terribly concerned.

Just for fun, last nite before bed, I dropped the temp in the cellar from 60 to 58 to see what the effect was on the humidity. This morning, cellar at 58, humidity had dropped a few points to 67%, down from the low 70's range it is normally in, but still well within the "recommendations". Once Fall gets here (it's still in the 90's every day) the cellar will go to 55 until Spring, be interesting to see what the effect is on the humidity. 

When I work in there and use the sink to clean equipment, carboys, etc., particularly using hot water, the humidity spikes up for a short time, not surprisingly.


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## jsbeckton (Sep 21, 2016)

I have a dehumidifier in my basement. I let that go up from 50% to 60% but that didn't change the humidity in my cellar. Curious to see what it is in the winter when my dehumidifier usually doesn't run.


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## Johny99 (Sep 22, 2016)

I'm on the edge of the desert. Humidity typically is 20-30% in the winter. So far no problems with corks although I've only aged 8 years so far. My issue is with topping of barrels. I have to it weekly. I'm going to experiment with the bucket and cinderblock this winter.


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