RD wrote:
The timing of nutrient addition is also worth mentioning. I've had
the best results by adding nutrients (DAP and Superferment) in 2
aliquots rather then all at once. The first half is added once
fermentation is started and the second at about 12 - 15 Brix.
Waiting until fermentation is underway may help avoid encouraging
growth among other microorganisms that you don't want to flourish.

RD


I also subscribe to the practice of incremental yeast nutrient additions
(two or three smaller aliquots) rather than all at once at the start of
fermentation.

Adding all the yeast nutrient at once at the start of fermentation
encourages a very active fermentation (observed as heavy foaming).
Highly active fermentations encourage carbamate production.

I try to minimize carbamate production... it's not good for us
healthwise and is largely avoidable. I get all the carbamates I 'need'
grin from french fries and other fried foods, so I like to avoid them
in my wine.

Carbamates in wine are naturally occurring metabolic byproducts of wine
fermentation, originating from the amino acid arginine. We can't
eliminate arginine from the naturally occurring amino acid 'soup'; we
can only minimize its conversion into carbamates by adding DAP in the
minimum incremental amounts needed to prevent stinky/stuck fermentations.

Gene