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Norskersword
08-25-2004, 02:56 AM
For those of you who don't know, some of us on the gotmead forum have been talking about the "gasohol" effect on many threads. "Gasohol" is what we call a mead that tastes a bit like "gasoline" or "jet fuel" and, although this usually dissapates with age, many of us have been curious as to what causes this phenomenon.

Although I am fairly new to mead and have only made 3 batches, all three of these have been victim to the gasohol effect. Why?

I believe now I know exactly what the cause is. Out of curiosity I bought a cheap thermometer and put it in the closet where I keep my batches. What I found was that in that little closet it is an average of 81 degrees! Last night when I checked it was a bit over this. I guess that since I've been living in CA my whole life 80 degrees doesn't seem hot and I never realized or was even concerned about paying attention to the temperature range of the yeasts I use.

The three batches I've done so far were Cote De Blanc, Montrachet, and Premier Cuvee. All three of these have resulted in Gasohol and all three of the temperature limits were 80 degrees.

The cause of the gasohol effect must be from exposure to temperatures beyond (even slightly beyond) the temperature tolerance of the yeast.

This is not just a lesson to me but to all meadmakers to pay attention to the temperature tolerance ranges of the yeast you decide to use.

My last two batches I just started made use of K1V-1116 and D-47. Luckily both of these have higher temperature ranges than 80 degrees, especially K1V-1116. It's no wonder these are such popular yeasts.

WikdWaze
08-25-2004, 03:03 AM
This is something that concerns me greatly. Georgia is every bit as warm as CA and our A/C system is busted. I'll either have to ferment in the bedroom where we have a window unit installed, or buy a second window unit for the spare room so I can ferment in there.

Norskersword
08-25-2004, 03:08 AM
Yes but it seems that all this depends on the yeast you decide to use. K1V-1116 is a very popular yeast that alot of people have had alot of luck with. I believe it's because the max temperature tolerence for it is 90 degrees. Unless your place tends to be over 90 degrees, you should be fine.

In CA it hasn't been that hot lately.

svaros
08-25-2004, 06:46 PM
Norskersword,
I actually performed the same experiment last night. I left my digital thermometer in the basement where I ferment my mead, and it stayed between 72 and 73 degrees for the past 2 days even though the outdoor temperature has been higher (the thermometer records the temperature high and low over time). This actually bears out your theory, in that my most recent batch (done with Premier Cuvee yeast) had less of the "gasahol" flavor than the first which was fermented last summer at the peak of a heat wave. My current batch done with Lalvin D47 shows no sign of the off flavors. I'm going to stay away from the Premier Cuvee yeast for a while. At least until the temperature drops a bit.

Best,

David

Norskersword
08-25-2004, 10:30 PM
Thanks for the post, Svaros. It is only a theory and I'm not pretending to know for sure, but it is interesting to hear something that supports this.

I was thinking Premier Cuvee was just a poor yeast to use, but now I'm thinking that it is just sensitive to heat. I think region plays a vital role in yeast selection.

ScottS
08-25-2004, 11:38 PM
I'm finding that no matter the yeast, keeping fermentation under 75 (72 is better) and above 60 is a good thing. Conveniently, this is the exact annual temperature range of my Michigan basement. ;D

WikdWaze
08-26-2004, 02:05 AM
Yes but it seems that all this depends on the yeast you decide to use. K1V-1116 is a very popular yeast that alot of people have had alot of luck with. I believe it's because the max temperature tolerence for it is 90 degrees. Unless your place tends to be over 90 degrees, you should be fine.

In CA it hasn't been that hot lately.
It does get well above that here, at least in the rooms with no A/C. I might be better off buying a small refrigerator and one of those control units to maintain the temperature the yeast prefer. This would be much more consistent than hoping the window unit A/C keeps the temperature in range. There's a good question. How long does the temperature have to be out of range before the yeast goes off?

Oskaar
08-26-2004, 03:13 AM
Here's an old brewer's trick.

Get one of those plastic tubs they sell at the local Wal-Mart or Grocery store. They're about $4.95 here in So Cal and I get them at Albertson's. They're brightly colored and will hold a carboy or corny keg just fine. Fill the container about one third full of water and add some idophor, a small amount of bleach or some other bacerio/fungistatic sanitizer to help keep the water from getting ripe and growing molds. When it gets to that point, it's time to change the water and wash the towel. Hopefully your fermentation (primary or secondary) is done and you can go to aging using the same trick until it cools down a bit.

Wet an old towel you aren't in love with anymore and drape it arond/over your containter (carboy or corney) being careful not to upset your airlock. I generally use a blowoff tube. Put a cheap fan in front of it and put it on low. Viola, evaporative cooling. I've used this during some very hot summers here in California and have had no heat related fouling of my beers, ales, even meads.

Oskaar

WikdWaze
08-26-2004, 03:25 AM
Or I could stand there with a palm frond and fan the carboy to keep it cool ;D

Seriously, I think I'm going to get a small fridge. We have cats, and they just love to mess with things. And an open container of bubbling water, such as at the end of a blowoff tube, would be too tempting for them. I can easily envision my gallon jug of fermenting nectar laying on it's side on top of the dresser pouring it's golden contents everywhere. The Mrs. would love that ::)

Norskersword
08-26-2004, 03:32 AM
Our cats havn't figured out yet how to open the closet. ;D

But I have noticed that when I open the closet and take a look our cats are fascinated by the bubbles in the airlock.

David Baldwin
08-26-2004, 04:34 AM
One of our cats is certain that my airlock is the embodiment of all evil. We went on vacation, and I spent a week worried about his ill intentions toward my burlap draped carboy - affectionately known as "Mr Bubbly"

Norskersword
08-26-2004, 05:04 AM
One of our cats is certain that my airlock is the embodiment of all evil. We went on vacation, and I spent a week worried about his ill intentions toward my burlap draped carboy - affectionately known as "Mr Bubbly"

Did he do anything to it?

David Baldwin
08-30-2004, 09:28 PM
No, he was a good kitty, and left my carboy alone. Of course he can't help but watch when I'm taking my hydrometer readings. He looks on as if I've lost my marbles, and am playing with matches and dynamite all at the same time. ::)

The carboy sits on a table over the cats food dish, so they are getting used to it making strange noises. They don't even run away anymore when it bubbles above them ;D