Punch Down and Adding Tartaric Acid and the Malolactic Fermentation Mixture

Kathy and I went to Tin Lizzie Wineworks late yesterday afternoon for a couple hours. During the time we punched down 12 fermentation bins, mixed tartaric acid to add to most of the bins and added the malolactic fermentation mixture to each bin.

There wasn’t much going on with fermentation. The yeast was added about 23 hours earlier. However there was a cap on the surface of each fermentation bin. The cap was strong enough to easily hold our home-made punch down. Breaking the cap was easy though. Dave Zuchero, winemaker, tested for the specific gravity and pH. Most of the bins had a pH that was higher than what he wanted so I measured 100 grams of tartaric acid, added two cups of water and stirred the mixture. I then added this to the fermentation bins and Kathy used the punch down to gentle stir. Our Cabernet Sauvignon needed the addition of Tartaric acid. Those making a Merlot did not.

The day before we prepared a malolactic bacteria mixture. Dave used the Lallemand Alpha 1-Step kit starter. The day before we dissolved the first package, the activator, in water. I then opened the second package the Oenococcus oeni bacteria and added to the mixture. Later, Dave added some must from the fermentation bin. About twenty-four hours later, I added about 7 cups of this mixture to the fermentation bins and Kathy stirred the musts. One of the reasons to co-ferment the musts is to take advantage of the warmer weather that we have now. If we waited until the primary fermentation would be complete before we added the bacteria, it would be added next month and November can be much colder in the winery. There also seems to be a bit of a push to co-inoculate.

What we did at the winery yesterday is more of the chemistry side of winemaking. Consumers do not readily think about this while drinking wine. There are many winery tasks that go into making the wine.

Cheers,
Terry