From the Wine Nerd
Winemaking can be romantic and fun, but it’s also hard and dirty work. One of my favorite dirty jobs around the production barn is cap management. No, it’s not trying on different hats and posing for selfies with the barrels.
Let’s start with the cap and why it needs managing. The cap is a layer of grape skins and seeds that forms on the top of fermenting red wine. The yeast eats the sugars in the grape juice and produces CO₂. The CO₂ pushes the skins and seeds to the top of the fermenting juice and then you get a cap. We don’t want that cap to stay there, we want it all mixed up with the fermenting juice for better color, aroma, and flavor extraction.
There are different techniques we can use to get this cap all stirred up. The first is called a punch down. We use a tool to punch the cap back down and stir it all up. Large fermentation tanks are too big to use the punch down method, so we pump-over. This means we pump the fermenting juice from the bottom of the tank and spray it on top of the cap to mix it up.
The last method is delestage (rhymes with sell-best-lodge). This is like pump over except we pump the fermenting juice into a different tank, allowing the cap to fall all the way to the bottom. We let the cap settle and then pump the juice back on top of the cap. It is a messy job and it one that cannot be ignored; it must be done every day. As long as we have red wines fermenting, I’ll be here managing the caps… and taking the occasional selfie.