Agriculture Reference
In-Depth Information
A wine can be made successfully in some cases without the
addition of nutritional building blocks for the yeast, but
adding those building blocks will go a long way toward
stacking the deck in favor of a successful outcome.
You will see wine supply stores selling many supplements for
yeast with names such as yeast nutrient and yeast energizer.
There is no universal standard, and so the precise ingredients
will vary with the supplier. In general, they will contain
purified sources of nitrogen and phosphorus at a minimum,
though many will also contain a variety of B-vitamins. Yeast
nutrient usually contains only food grade ammonium
phosphate, whereas yeast energizer will contain this along
with magnesium sulfate, killed yeast, and the entire vitamin B
complex; of which thiamine (vitamin B1) is the most
important. Sometimes you may see urea as an ingredient. If
you do, don't worry. This is purified food-grade urea that
supplies nitrogen for building proteins and it is perfectly safe.
Yeast cell division requires proper nutrition.
I would recommend using yeast energizer in preference to
yeast nutrient. But if you use yeast nutrient instead, at least
add a 100% RDA thiamine tablet and a pinch of Epsom salt in
addition for each gallon of must.
The cell walls of yeast also require lipids (fats), and such fats
are in short supply in some wine musts—especially meads
