Day 5:

I checked in on my must, and was delighted to hear some faint bub­bling under the cap.  Suc­cess, the yeast are get­ting to work!  I punched down the cap, a rit­ual I will be doing 4–5 times per day until the fer­men­ta­tion is com­plete.  I want to make sure the yeast have enough air to do their job, and extract all that lovely color and fla­vor from the skins!  The must is at about 65°F, and will increase in tem­per­a­ture as the fer­men­ta­tion continues.

Day 6:

Even more gur­gling activ­ity, and quite a few bub­bles com­ing up as I punch the cap down.  The must has warmed up a lit­tle to about 68°F.

Day 7:

Today I added 4g Fer­maid K (yeast nutri­ent) to make sure the yeast have all the nutri­ents need and to keep the fer­men­ta­tion hum­ming along nicely.

Day 8:

More punch­ing down, and yet more activ­ity going on in the must.  Tem­per­a­ture is now at about 70°F.  I checked in on the sugar, which was at about 18 Brix.

Day 9:

I added one last small dose of yeast nutri­ent to the must.  Tem­per­a­ture is 75°F and Brix is at 14.  The con­ver­sion of sugar to alco­hol is obvi­ous from the smell of the must and the juice feels markedly less sticky.

Day 12:

The fer­men­ta­tion has been hum­ming along nicely and the sugar drop­ping day-by-day.  The tem­per­a­ture has held steady at about 75°F.  It never got very warm, which I am okay with.  I think with the cold soak, and what is shap­ing up to be a 9-day pri­mary fer­men­ta­tion, I should get plenty of fla­vor and color extrac­tion while pre­serv­ing the fruity char­ac­ter of the grapes.

The sugar level is in the low sin­gle dig­its now, so I made arrange­ments to rent a wine press on day 14.  In the mean­time I’m clean­ing my ferm locks, stop­pers, tubes and car­boys in prepa­ra­tion for press­ing the wine.

I’m also kick­ing off the “sec­ondary” or Mal­o­lac­tic fer­men­ta­tion by adding a mal­o­lac­tic bac­te­ria cul­ture to my must.

The tim­ing of this move is debat­able.  Some wine­mak­ers sug­gest doing this early in the pri­mary fer­men­ta­tion where there are plenty of nutri­ents and elbow room still left by the yeast to ensure the bac­te­ria get a good start.  Oth­ers hold off until the pri­mary fer­men­ta­tion is com­plete and there isn’t any sugar for the bac­te­ria to poten­tially feast on and make unde­sir­able by-product fla­vors in the wine.  I opted to start my mal­o­lac­tic con­ver­sion at the tail-end of the fer­men­ta­tion, when most of the sugar is gone, but the must is com­fort­ably warm for the bacteria.

Read about the next step of the process, press­ing the wine.

Related Posts:

• Adven­tures in Home Wine­mak­ing: Press­ing the Wine
• Adven­tures in Home Wine­mak­ing: Adjust­ments, Yeast and Fermentation
• Adven­tures in Home Wine­mak­ing: Crush and Cold Soak
• Chap­pel­let 2009 Napa Caber­net Sauvignon
• Fran­cis­can 2005 Sty­lus Napa Val­ley Caber­net Sauvignon