Fermentation Speed

[Tim]

I was wondering if my fermentation's are happening too fast for my reds. My wines go from 24 ish Brix down to 0 in under five days usually. The cap still forms so there is still sugar fermenting so I dont know if I just need to get a more accurate hydrometer for measuring the lower Brix. If you go to my website http://www.vinetowine2008.com and go to the logs page you can pull up a PDF file of my fermentation's and see the measurements. Are others seeing the same type of fermentation speeds? I guess it is ok, I still will not press for at least 7-14 days so I get good extraction, and at least the fermentation's are not stuck, knock on wood. Thanks for any feedback.

[Tim]

I keep them in the basement now, I will try the fans and see if that helps with the Brehm grapes coming in later. Thanks for the tips, I'll let you know how it works out.

[Dave Nelsen]

That high temp explains the speed of fermentation. I'd recommend finding a cooler environment (I use a dry basement with a cement floor at about 65 degrees. Further, when the must hits 80 degrees, I use fans on the side of the fermentation vats to keep it from going higher. I'm surprised that 90 degrees doesn't cause off flavors.

[Tim]

My cap temps get well above 80, I usually peak out in the upper 80's trying to keep them below 95. The caps are still forming after 7 days so I know that there is still sugar to burn and the temps are down back to the low to mid 70's. Usually on day 3 or 4 is when I have peak temps. Last year I did an extended maceration with my cab sauv and it turned out great. I think I will try it with most of this years batches. If you check out my website I have logs of the fermentation this year. How do you keep your temps so low?

[Dave Nelsen]

Yes, a five day fermentation is a bit fast for full color extraction among other things. Some yeasts burn faster than others (I recall Assmenhausen taking nearly three weeks one year; and I'm not talking about a disease) but my guess is that you may benefit from lowering the room temperature a little bit. Aim for a peak must temperature of 75-78 degrees, and definitely never let it get over 80 (bad "cooked" flavors).

If you have a fairly oxygen-free post fermentation environment, leaving the wine on the skins for a few more days would be beneficial. Pump nitrogen or better yet, Argon, into the container. Or throw in some dry ice (carbon dioxide).