Three times a day we take the temperature of the wine and the sugar level and take the appropriate action. Because fermentation stops between 36 and 38 degrees Centigrade it is important for the winemaker to test the wine regularly. This means, for the first rapid part of fermentation, we could be in the cellar until 1 or 2 am doing one of two things to help regulate temperature. The first thing is called Remontage.
Remontage is done at least three times a day for each vat of fermenting wine. It involves cycling wine from the bottom of the vat back over the top of the cap. This process does two things: first it helps to aerate the wine and second it evens out the temperature of the entire vat. The wine below the cap is slightly cooler and most of the yeasts and enzymes are living, eating and producing alcohol in the cap, and it is important to keep it wet with fresh sugar for the little guys to consume. The second technique the natural winemaker employs for controlling temperature is called Delestage. Delestage, also called racking off, is when the winemaker removes the liquid from the fermenting vat and moves it to another container in order to cool the wine back to a safe level. Delestage at Casa Raia is done by circulating cold water into two flat, stainless steel containers, submerged in the wine. This involves more work, more cleaning and slows fermentation so it is done more or less at the last possible moment, when the wine is around 34 or 35 degrees.
Winemaking involves intuition, certainly knowledge and skill, especially when one is not using chemicals to control the process. If the wine gets too hot, or too cold, fermentation stops and you have too much sugar and dead yeast. Big problem. Fermentation, once it begins, can go at any speed. One vat of Brunello from the same vineyards, picked the same day as the others might ferment much more slowly than the others. One might take days to start, while another only hours, and this has nothing to do with the quality of the final wine, and is part of the natural process. The winemaker must be patient and listen to the wine and help it along the way with as little interference as possible. This means long hours in the cantina, and lots of work, but it has a satisfaction that is absent when winemaking is reduced to measuring out chemicals and dumping them into "wine".
When you open the door to a vat of naturally fermenting wine you feel the heat, the smell of fermentation and you know that it is alive and there is something indescribably amazing and beautiful about that. Man has been taming these tiny wild yeast beasts since agriculture was invented, and it fills you with a wonderful feeling of connection to history and your fellow humans. Or maybe its just the CO2 messing with your head.....