Let’s do the numbers

Garagistes under glassGot the numbers back from ETS, and as we guessed from the taste of the grapes, the Merlot should have been picked earlier. The upshot is that we’ll need to strap the Merlot to the treadmill and tone it up a bit, adding some acid to drop its pH into healthier territory and sharpen its fruit, and perhaps add some water to pull the potential alcohol down into balance.

The Franc looks a lot better, but like the Merlot, will need to be monitored through the ferment because of their low yeast assimilable nitrogen content (or more colorfully, YANC). That potentially soporific term essentially characterizes how much nitrogen the yeast have to feed on to keep themselves fit and healthy through the ferment. From a paper by the Food Science and Technology department at OSU:

If the levels of fermentable nitrogen are too low, the total cell biomass produced will be low, the yeast fermentation may be slow, and the fermentation may stop or `stick’ before all the fermentable sugar is utilized. Yeast under nutritional stress due to nitrogen deficiency may also produce hydrogen sulfide (rotten egg) and other sulfur compounds with offodors

So we’ll definitely be adding some yeast nutrient and tasty-sounding di-ammonium phosphate (DAP) to both of these ferments to keep the yeasts happy and healthy.
The complete numbers and some more comments after the jump…

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