Thursday, February 21, 2008

Inoculating For Malolactic

Vinquiry delivered the numbers today from the Napa River Cabernet sample I took to them yesterday:

Alcohol13.77% (v/v)
Malic Acid1.22g/L
Volatile Acidity0.76g/L

As I suspected the alcoholic fermentation is complete and it is time to inoculate for malolactic. The pH is close enough to where I want it (about 0.05 units higher than I predicted) for the time being. I will evaluate the pH and the texture on the palate after ML to see if a small acid addition might be in order.

The alcohol is correct for the initial Brix value of the must. The V.A. is higher than I expected. Some folks would panic at this number, but I'm not concerned. There is no evidence of spontaneous lactobacillus infection, nor was there any sensory or visual evidence of spoilage in the fruit before fermentation. In decreasing order of probability, the number is 1) perhaps a lab artifact, 2) evidence of yeast stress from the rapid temperature increase I subjected it to, or maybe from the low inoculation rate, or 3) due to slight bacterial activity that occurred because I used a lower SO2 rate on the must.

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