Potassium Metabisulfite

[rebusify]

Today I manually destemmed and crushed 200lbs of pinot noir grapes. Got two 17 gallon tubs about 75% full and one 10 gallon tub about 50% full. The amount of potassium metabisulfite that I put in today was a little under half a teaspoon in the 17 gallon tubs. The measurement I was going for was about 1/4 teaspoon for every 100lbs of grapes so not sure about the math. Am I far off? I'll be letting these sit for about 20 more hours then press them off for my Rose.

 

[user 36973]

Today I manually destemmed and crushed 200lbs of pinot noir grapes. Got two 17 gallon tubs about 75% full and one 10 gallon tub about 50% full. The amount of potassium metabisulfite that I put in today was a little under half a teaspoon in the 17 gallon tubs. The measurement I was going for was about 1/4 teaspoon for every 100lbs of grapes so not sure about the math. Am I far off? I'll be letting these sit for about 20 more hours then press them off for my Rose.

Back of the envelope...

200lb of grapes skin fermented should yield 13lb/gal, so 15.4 gal or 58.2L of wine. Pressing for a rose will mean a slightly lower volume.

1/2tsp of kmbs is about 2.5g. It's 57.6% sulfites, so your dose is 2.5*0.576/58.2 is 24.7ppm.

This is a sufficient dose. The sulfites are quickly bound up on the must, for what it's worth. Happy fermenting