Does yeast ever sleep?

Does yeast ever sleep? I’m in my third day of alcoholic fermentation, and it was a hot one. Thank haven the must temperature didn’t reach 90 deg F. Managed to keep it around 85 deg F. Its 12:00 pm EST punched down the cap and stirred the must for the last time today. Hopefully cooler weather arrives tomorrow. I don’t know if I’ll allow the cap to sink to the bottom of the fermentation vat, this only leads to problems when trying to get the free-run wine out using the spigot at the bottom of the vats.

Salute (and good night)

Does yeast ever sleep?

I don't know about yeast, but when my alcohol level goes up, I go to sleep.

Does yeast ever sleep?

Yes, at about 15% alcohol--they begin to sleep to death

Yes, at about 15% alcohol--they begin to sleep to death

Actually, many current yeast strains are selected for acohol tolerance.

Here's a question for you - what is the highest alcohol you've seen in an unfortified table wine?

I recall one at over 17% - a late harvest style Zin from the 80s - and it STILL had some RS!

Bill
I think they've cracked 18% in Oz IIRC. Seen it discussed on the Auswine forum from recollection. Not exactly going out of my way to taste such wines though...
regards
Ian

Well Bill, I did say they "begin" to sleep at 15%--even the new "Eveready" strains probably slow down at that point.

I was just being cute; something nature didn't give me naturally...

As for unfortified wines beyond 15% alc, I am wary of every last one of them, even the dessert ones.

Maybe I should have asked the amateur and professional winemakers who visit this board- what is your cap management routine for red wine production?

Once my shipment of grapes arrives, I crush them almost immediately or ASAP. This usually results in a must temperature of 40 to 60 deg F. Depending upon ambient temperatures I let this must stand for 24 to 36 hours, stirring it occasionally and monitoring the temperature. In some years when ambient temperatures are low I find myself heating the must slowly to get it up to favorable temperatures for the yeast strain I use (70 to 75 deg F). This year I was lucky ambient temperatures brought my must temperatures up to 65 to 68 deg F. After the permitted time I inoculate the must with a cultured yeast strain, and let it stand for 24 hours. After 24 hours I begin my stirring routine. During the beginning of alcoholic fermentation, or when ambient temperatures allow me to maintain a must temperature of 70 to 75 deg F, I punch the cap down and stir the must 3 to 4 times a day. However when hot weather settles in on my area (like it did this year), and must temperatures begin to rise into the 80’s (deg F) I find myself punching down the cap, stirring the must, icing or hosing down my vats 6 to 8 times a day, just so that my fermentation does not “runaway”. Yes this does mean waking up in the middle of the night (or morning) and repeating this process (in this sense, yeast doesn’t sleep). When fermentation starts slowing down (usually after three days of violent fermentation I go back to the 3 to 4 times a day routine of punching down the cap and stirring the must.

Salute

My technique for red wine is quite different. I get the grapes, crush and destem within a few hours and add SO2 to about 60ppm (or about 1/4 tsp per bushel of grapes) and stir. I put the primary container in the garage. After about 12 hours I simply add dry yeast directly to the must and stir again. I've never used a starter, except for secondary (bottle) fermentaion of bubblies and never had a stuck fermentation. Then I punch down the cap twice per day, stirring vigorously. When the cap no longer forms, I press it out and put into carboys. About a week after fermentation has completely stopped, I rack the wine. If I don't want M-L, I add 80ppm SO2, rack 2 weeks later, cold-stabilize and rack again. If I do want M-L, I let is sit for a few months in the basemant before racking and don't cold-stabilize.

Hi Howie,
On an average how long does your primary fermentation take place?

My goal is to keep primary fermentation going for at least 5 days (when ambient temperatures permit, and if I work hard at trying to maintain acceptable temperatures, I can extend this). After crushing the fruit I do take “must numbers” (Brix, S.G, TA, and pH), make adjustments if desirable levels are not obtained. I do sulfite the must, but depending upon the condition of the grapes and pH, I might add anywhere from 60 to 100 ppm. I do use a crusher-destemmer (and it does a great job), but we do like to ferment with a small percentage of the stems (what can I say my father is “old-school”). Downstate NY we can get some fairly hot days in September and even October, and if I don’t try to manage my must temperatures, primary fermentation could be completed in 3 days. (BTW Howie I’m dealing with 50 gal capacity open top primary fermentation vats from Italy holding approximately 30 to 35 gals of must).

Salute

High temperature is not a problem for me, as the late September through October temperatures here, while they may occasionally reach 80 during the day, more typical is 60ish, with lows in the 50s or upper 40s. In addition, I use much smaller containers than you do. I use either a 10 or 20 gallon plastic open top drum with a lid, followed by either 5 or 6.5 gallon carboys. Generally, the reds ferment for 10 to 14 days on the skins. For Steuben, I ferment it like a red and try to extract as much color as I can, but due to low levels of pigment, it ends up being a Rose. I also have a crusher-destemmer, which I purchased last year, but I have a really old press that either should be rebuilt or replaced.

After about 12 hours I simply add dry yeast directly to the must and stir again. I've never used a starter, except for secondary (bottle) fermentaion of bubblies and never had a stuck fermentation.

I don't use a starter per se either, but I do hydrate my yeast before pitching it into the must by adding it to about 50 ml of 40ºC water for fifteen minutes - they say that this helps the yeast better adjust to the environment and, I think, osmotic stress that they'll encounter in a sugary solution. I'm not sure how critical it actually is to a successful fermentation, though.

My favoured yeast from among those that I have ready access to remains the EC-1118 (Prise de Mousse). It has a whopping alcohol tolerance of up to 18%, which is why I use it: I am virtually guaranteed that my wine will turn out bone-dry, exactly the way I want it.