Yeast Nutrient Question

Generally yes. The excpetion is if your must is severely nitrogen deficient.

Pp

I have been using it without DAP for 3 years with no issues.

Joe

Any comparisons; available nitrogen - cost per usage, etc?

DAP is just nitrogen, Fermaid or Superfood contain other things so they're supposed to better for the yeast overall. There is a table around the Web that shows what to use for what types of must - some need both Fermaid and DAP for best fermantation, but in practice, this is hardly needed - plus you won't get a good wine anw if you have to deal with grapes like those.

As for cost, this stuff is so cheap overall that it hardly matters - but DAP is cheaper.

Pp

I am curious to know how much Fermaid K and how much DAP one should use per 100 pounds of grape must? I was thinking 15 grams of Fermaid per 100lbs of must and 30grams of DAP per 100lbs. I feel with this combination I should never have any fermentation problems.

Jim - I'll assume your must is 22 brix or SG 1.093. Water weighs about 8.3 lbs per gallon so your 1.093 must would weigh 9.1 lbs/gallon. Your 100 lbs of must will be about 11.0 gallons. In my experience grape must contains about 2/3 juice and 1/3 skins, pulp and seeds. Using this value you have about 7 gallon juice. I've been using

2 grams Fermaid per gallon juice. In the past I also added 1 gram DAP per gallon juice. So, I would add 14 grams Fermaid and 7 grams DAP to the 100 lbs must. Last fall I only added Fermaid and had no fermentation problems.

Bill Frazier Olathe, Kansas USA

The recomended dosage on Scott Lab web site is 25g of Fermaid K per 100 litres of juice, so given Bill's calculations, it should be about a 1/2 of your estimation - 7-8g per 100 lbs of must. They recommend to add the whole amount at 1/3 sugar depletion.

I don't use DAP so not sure about the dosage - just Google it.

Pp

To those of you that have posted thank you for the advice.

Jim,

The manufacturer makes the following recommendation for Fermaid K:

"For normal applications, the recommended addition rate of Fermaid is 5 grams per 20 liters. Fermaid should be stirred into the must just prior to the yeast inoculation." Fermaid includes a nitrogen source (which may be DAP), and so this may be all you need to add.

Opinions on DAP quantities and when to add them vary, but a good starting point is the label of the DAP you have purchased. There should be usage instructions from the manufacturer listed there. Just be aware that the Fermaid K does include a nitrogen source, and that reducing the addition of the DAP is probably a good idea based on that fact. You might consider contacting Lalvin to ask this question of them directly.

Cheers, Ken