CALCIUM CARBONATE CaCO3
(for juice BEFORE
fermentation)
NOTE:
Acid reduction with Calcium Carbonate, Potassium Bicarbonate, OR
Acidex can not exceed more than a .4% total reduction either by combined
or any one application.
Note:
There are 28.3495 grams per ounce. One ounce is 12 1/2 teaspoons,
there are 3 teaspoons in 1 tablespoon.
Approximately
2.5 grams of CaCO3 will reduce the acidity of 1 gallon by 0.1%
CaCO3
.3-.4 grams /liter will increase the pH by ~ 0.1
This shift must be taken into consideration and is the
restriction in the use of CaCO3 and the other acid reduction aids noted
above. The pH shift will
vary depending on the chemistry of the must.
With a initial pH of 2.95, the addition of .3
grams/liter being equivalent to 1.13 grams/gallon (1 gallon = 3.78
liter), at the rate of 2.5 grams per gallon, will shift the pH by
~.22 resulting in a pH of around 3.17.
If you have a pH meter, put it to use during any acid reduction
using these additives. Do
not go above a pH of 3.5; 3.4
is better for a maximum pH.
As CaCo3
reduces tartaric acid first (by producing calcium tartrate), it is
important to treat only a portion or one
third of the total volume of juice.
When fermenting on the skins, you will be able to draw off
approximately 1/3 of the anticipated juice volume after 2 days of
fermentation. Treat this portion with the total amount calculated
to reduce the entire final volume. To calculate the amount
needed for reduction:
1.
Reduce the initial acid reading by .12 to allow for acid reduction during
fermentation OR by .20 to allow for combined reduction
due to fermentation and cold stabilization.
(Cold stabilization is highly recommended.)
This figure is the “potential natural acidity.”
2.
From the potential natural acidity subtract the desired total acidity.
This depends on your taste.
However, never go below .6 or the stability will be affected.
This will yield the acidity to be neutralized by the calcium
carbonate.
3.
If the acidity to be neutralized is greater than .4, use the lower figure.
Do not adjust more than .4%.
You may want to consider the use of sugar water (10-15%) and or
blending with a lower acid juice.
4.
If the reduction is .4% and 2.5 grams will reduce the acidity of 1 gallon
by 0.1%, the amount required will be 2.5 x 4 or 10 grams per gallon
times the number of gallons, i.e. 5gallons (times) X 10 = 50 grams for 5
gallons. Add this
amount to 1/3 of the entire volume.
This will strip most of the acids from this portion.
·
Add this amount of calcium carbonate slowly, over a period of 1 hour with
frequent agitation.
·
Allow this to settle for 24 hours and rack, adding back into the total
volume. This helps to
prevent excessive distortion of the entire natural acid profile.
Ferment as desired, racking 3-4 times.
*Calcium tartrate is not stabilized by cold.
In fact these crystals grow
better at warmer temperatures around 60o F. To protect against late
Calcium Tartrate formation in the bottle, filter a wine and let it sit
for 4-6 weeks and then bottle, sterile filtering if necessary.
Reference:
Home Winemaking Step by Step, J Iverson, Tom and Marcy Mitchell,
*Thomas Henick-Kling, Associate Professor Cornell U
