Rising Brix

With this year’s black rot causing only limited damage and the birds seemingly accepting that they’ve eaten every possible grape they can reach without being caught in the protective net, it’s finally starting to feel like I might actually be harvesting my first crop this year. 

I’ve never picked grapes before, much less ones I’ve spent three years nurturing, so the prospect is a little nerve racking.  And, like most first attempts in my winemaking education, I’m relying on my books to show me how it’s done.  For the past several weeks the ripening grapes have been undergoing a chemical metamorphosis as the intense acidity level slowly dissipates and the sweet sugar content slowly increases.  The trick then, is to harvest your grapes at the precise moment when the sugar and acidity have reached that perfect equilibrium leading to the ideal balanced wine. 

For red wines, textbooks say that moment arrives when your sugar content is in the range of 20 to 24 degrees brix and your total acidity is in the range of 6 to 7 grams per liter.  I have a kit that measures total acidity, but it’s a tad cumbersome, imprecise, and uses more of my precious juice than I would prefer, so so far I’ve been focusing my measurements on the sugar level, which can be easily calculated by applying a few drops of juice to my handy refractometer (shown here).  Over the last four weeks, the sugar content has steadily increased from an average brix calculation of 13.5, to 15.3 to 18.5 (the last big jump was because I was on vacation for a week and therefore not able to measure).  With a rate of increase of about 1.7 brix per week, my grapes should be right in the desired sugar range in about two weeks. 

The prudent thing at that point would be to check the acidity level before I harvest, but I know myself well enough to know that by that time, I’ll be too excited to do anything but pick those puppies and bring them home.  Besides, I can always adjust the acidity level in the winemaking process if I have to, and one of the few good things about having an imperfect palate is that you are less offended by an imperfectly balanced wine.