Grapes Into Glass
The wild grape wine that I started last week has been fermenting enthusiastically. I drew a sample last Saturday to measure the specific gravity and pH, and taste of course.
A Wine Thief in action.
The s.g. measured 1.050, so I knew that by Sunday the must would be ready to rack into glass. Sure enough, a hydrometer measurement Sunday read 1.040, right where I wanted to be. Vigorous fermentation leads to a firm cap that can easily be skimmed off before racking.
Happy bubbles beneath a solid cap
The wine had been on the skins for sufficient time to extract plenty of color. I didn't press out the cap as a taste of the must lead me to believe I had enough tannins for this wine and further extraction wasn't needed. The acids are still pretty sharp, the pH had dropped slightly from the start of primary fermentation, so I decided to add a benign bacteria culture (Oenococcus oeni) to induce malolactic fermentation in the wine.
The naturally produced acids in grapes are predominantly two types, tartaric, and malic. Northern grown grapes are often more acidic due to lower ripeness levels and reducing the acid level helps to balance a wine. Malolactic fermentation converts the malic acid in wine to lactic acid which has the sensory advantage of being smoother and less sour on the palate.
I racked off a 5 gal. carboy from the primary, and added the malolactic culture. I racked out another 1 gal. jug to use as a control, and an additional 1/2 gal. container went into the fridge for topping up. Airlocks were attached and are bubbling merrily. In a month I'll draw some samples and we'll see if the malolactic fermentation is having the desired effect.