View Full Version : Heat on Fermentation and Aging

06-11-2012, 08:55 AM
I'm living with no AC, so the temperature in my living area is always changing. It's early in the summer so it's not too bad, temps in the high 70s to high 80s most of the time, but there are days coming soon, and I'm sure later in the summer where it will be really hot for longer periods of time. I have a few different meads going right now, and was just wondering how much heat can throw off fermentation or aging. I'm using bread yeast in everything which likes warmer temps, but high 80s and into the 90s are pushing it. If I had to guess, I'd say the inside temperature is about 5 degrees cooler than outside at the hottest part of the day. I store my carboys under the sink along with a few bottles from earlier attempts that I'm trying to age out some. Will this heat/constant change in temp result in strange flavors or throw things off?


06-11-2012, 09:17 AM
Some yeasts are very temperature sensitive. D47 being a good example i.e. ferment it too hot and get lots of fusels (not good).

It's probable that a lot of yeast will do stuff like that if fermented outside their temp threshold, so the obviously answer is to use a yeast that's more tolerant/has a wider range. Like K1V-1116 or if you can get it, M69 (I think that's the number). K1V is Montpelier strain so from a hot area, M69 is a Spanish isolate, so also more heat tolerant than some.

As for ageing, bulk is better, as its a reasonable compromise to prevent inconsistency from bottle ageing that isn't done in a climate controlled warehouse or similar i.e. it will all taste the same if bulk aged. Though the temp control for storage is usually in the mid-50's.

06-11-2012, 09:37 AM
I don't have enough experience with bread yeast to tell you how those high temperatures will effect the mead.

Check out Lalvin Clos (http://morewinemaking.com/view_product/11425/103218/Dry_Wine_Yeast_-_Clos_8g) strain of yeast, RP-15 (http://morewinemaking.com/view_product/9481/103218/Dry_Wine_Yeast_-_RP-15_Rockpile_8_g), K1V-1116 (http://morewinemaking.com/view_product/16457/103218/Dry_Wine_Yeast_-_K1-V1116_8_g) and ICV-D21 (http://morewinemaking.com/view_product/16514/103218/Dry_Wine_Yeast_-_D21_8_g) for fermenting at higher temps (each yeast name is a link to the strain in the MoreWine catalog)

Medsen Fey
06-11-2012, 10:52 AM
To ferment in the 80s there is some evidence that K1V & D21 can produce a good traditional mead, but there haven't been many documented reports. In the 90s the only example I've heard was in an old book which mentioned Tokay yeast - which, by the way, did not do so well in my test @ 84F.

As for storage, those temps are going to cause accelerated aging with oxidized, Madeira-like aromas. In a traditional mead, these may not be bad, and you may still wind up with a mead that is enjoyable, but that sherry-like character will be seen as a fault by some.

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Valhalla Mead
06-11-2012, 02:03 PM
Fermenting at above recommended temperatures for your yeast can produce troubling (or at best annoying) esters and phenolics. Not to mention the generally more apparent increase of an astringent profile and body of the mead.

All of this can be solved with a temp control setup of which a few members have posted cost effective ways to go about creating them.

If that option is out then you can rely on a few tricks to reduce the impact of these by aging in oak, using an M-L fermentation after secondary, increasing/decreasing ph balance or simply doing some blending with other base set meads you have.

In some cases, and dependant on your yeast strain, high degree fermenting the must might leave these flaws in and may never age out.

Patience is a virtue and satisfaction is its reward!

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06-11-2012, 09:03 PM
From what everyone's been saying it sounds like I am screwed. I've had 2 batches aging and four currently fermenting, and it looks like I'm going to want to get them out of the heat asap. Fortunately, I think I may have found a friend with AC who is willing to let me store them in his house and let me come check up on them frequently.

Medsen Fey
06-12-2012, 10:47 AM
From what everyone's been saying it sounds like I am screwed.

Not necessarily. Some high temp meads can be quite good. Just keep good tasting notes. For what its worth I have some batches aging in my attic where it gets above 100F.

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Chevette Girl
06-12-2012, 11:30 AM
EC-1118 and K1V-1116 don't seem to have been terrible for me when I was still making wine in the kitchen (no AC, south-facing kitchen, believe it or not Ottawa can get pretty hot in the summer). No, you're not screwed, just maybe a little more limited in yeast selection. I now brew in the basement, but I only use D47 in the winter. And even if things are warm, a tub of water and a wet towel or t-shirt can be used to keep things cool.

06-14-2012, 03:39 PM
I was wondering about storing bottles where I have no AC, no cool basement or extra fridge space, etc.

Right now I only have a few bottles in the closet of my "brew room/office/band room/man cave" But by the time next summer rolls around I'll have several cases of mead bottled, and it can get pretty warm (80+) in the hottest part of summer.

I'm hoping to pick up a used fridge that I can put in the garage and keep at around 50 degrees for bottle storage, but if that doesn't happen for some reason does anyone have any other suggestions?

Medsen Fey
06-14-2012, 08:37 PM
... but if that doesn't happen for some reason does anyone have any other suggestions?

Develop a taste for sherry?

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06-15-2012, 11:58 AM
Develop a taste for sherry?

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<Smirks> Thanks Medsen!
Actually, that's pretty much the kind of answer I was expecting. :)

Chevette Girl
06-15-2012, 02:44 PM
I've had wine stored upstairs (90's in the summer) that hasn't oxidized, so it's not an absolute given...

And maybe you could put some form of insulation around your wine storage? Even a few blankets over the box of wine bottles might mitigate the worst of the temperature fluctuations.

06-15-2012, 03:33 PM
My spare room where I am currently storing/aging everything is generally the coolest room in the house, but when the temperature spikes it can still get pretty warm in there.

Blankets huh? I hadn't thought of that. If the extra fridge doesn't pan out I'll keep that in mind. Of coarse, I have about a year to save a little cash and look for something, but, you know - why do today what I can put off until tomorrow? ;D

Valhalla Mead
06-16-2012, 11:37 PM
You could always try swamp coolers...cheap and efficient

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