Depending on the extremes, and the variation of day to day temp, you’re more or less right. That was actually my point: the bottle temp will typically not reach the height of the air temp. So the high temps bottles are exposed to should be a few degrees less than the air temps Jim is measuring.
Here’s a thread from a couple of years ago with some temperature measurements and graphs to illustrate this:
Just to answer the question, the stats I posted were air temp, with the sensor resting atop bottles of wine in the middle of the wine rack.
I think the idea of doing a bottle temperature sensor through the cork into water is a great idea. Any ideas about where I can get that kind of thermometer?
Thanks for all the comments. I feel relaxed about the wine storage.
Terrific thread!
I too have a underground passive cellar with similar numbers
no rapid changes, it’s all good
+1000
You can make the bottle probe pretty easily. I bought a cheap indoor/outdoor thermometer from the local hardware store that had a probe. I then took an empty wine bottle and filled it with water, stuck the cork in and drilled a hole just large enough for the probe to go in. Stuck the probe through the cork and sealed it with silicon. I did mine about 10 years ago and its still working fine.
I now have two years of data from my passive “cellar”. Temperature was recorded hourly with a Lascar data logger.
May 2016 - May 2018: high 69, low 58, average 63.5
There was never any daily variation greater than one degree, which I think is good. However, the overall yearly range and the 69 degree September recordings cause me concern. I am strongly considering converting a seldom used basement bathroom into a real active wine cellar, but the expense is signifcant. So,considering the above data, should I bite the bullet and get the active cellar built? Or are these numbers totally acceptable and I am worrying for no good reason?
I would not worry a bit, Jeff. I bet your 69 degree air temp in Sept is 65-66 at most in-bottle for the month
I would love love love to have a passive cellar like this! Here in Napa Valley, basements are not common. And if they were, a heat wave of 100+ degrees for several days would not produce good results. Enjoy your cellar and your cellared wine: my opinion is that you have absolutely nothing to worry about.
So I have no need to worry about my four remaining bottles of Black Cat?
not in.my opinion.
I am a little late this this thread, but, that is a wonderful passive cellar, both for average temp and humidity.
I live in Northern New Jersey and have a passive cellar in my home. It is currently cinder block and is not insulated at all, but it used to be an older wine cellar of the Italian family that owned it since the 50’s. It is an isolated room in my basement with its own solid wood door and has 3 walls that are at the exterior of the home (3/4 of which are underground). I generally store my bottles on the concrete floor of the 10x10 room in order to maintain the coolest/most consistent temperature.
That said, I keep my sensor at floor level and observe temperatures in the mid 50’s in the winter and cooler months up to the low 70’s in the hottest summer months. Although my daily temperature fluctuation is generally never greater then 1 or 2 degrees. Average humidity ranges also from 50-60s in the winter to low 80s in the summer.
That said, I have laid down California Cabernet for years 8 years or more without any hint of bottle age issues. I will admit, I was initially concerned with the 71-72 degree temps in the summer, but between the humid/dark storage along with consistent daily temps, the few months of summer temps do not play a long term factor in aging, that I have been able to observe.
So the fact that you have temps consistently in the mid 50-60s with great average humidity, I would say you have the ideal passive cellar.
Also, I remember reading that the French Chateaus even prefer the temperature variations in their cellars as part of the natural aging process of wine, so I would argue that your passive cellar would be ideal, even compared to temperature controlled storage. (especially if you consider the cost and hassle).
No worries at all.
I’m not freaked out by temperature variations, or temps at 60 or a bit above. But I think prolonged temps in the 70s will likely advance your wines. As I recall, both acetic bacteria (vinegar creators) and brettanomyces multiply rapidly after the high 60s.
My understanding is that doors and ceilings are often the weak point in cellar insulation. I wonder if an insulated door and some insulation on the ceiling – pretty simple changes – might bring down those peak temperatures. (You didn’t say anything about the fourth wall – I take it probably an uninsulated interior wall.)
Never heard that. If anyone said it, it sounds like a rationalization for their existing cellar conditions.
John, yes, the entire cellar is only cinder block, so no formal insulation outside of the foundation. I am sure I could squeeze out a few degrees with some rigid insulation, the house has been a bit of a fixer upper and am currently tapped out with other projects the wife has me doing, so unfortunately have not had the time or funds to invest in cellar enhancements.
I think at best, I would get to the mid 60’s with insulation, the concrete slab of the basement is about 6 feet below ground level. Soil temps that far down this time of year are still around 65, but yea, still more ideal than 71.
One benefit I have is that, my wines rest on the concrete slab itself, so bottle temperature is below 70 degrees in summer (that measure was ambient air at about a foot off the ground).
Either way, I’ve opened up some mid 2000’s Cabernet over the last few months and they were quite tasty. Perhaps if I lose a good bottle at some point I will be more motivated to do something. But after almost a decade, everything is still drinking as it should.
Honestly one concern I do have, is that when I insulate the cellar, I am debating/concerned about whether dry locking the cinder blocks is going to throw my humidity to lower levels than desired. So not sure if anyone has dealt with that in their passive cellars or if that has caused a problem.
That water is probably about ready to drink, don’t you think?
I agree with this. Your cellar is almost ideal. A bit of insulation might cap those monthly/daily highs. Definitely worth the modest investment.