In winemaking, what is racking, and why is it important?

Dear Dr. Vinny,

A friend of mine works at a winery and said he hates “racking.” What does that mean?

—Dale, Phoenix

Dear Dale,

In the simplest terms, racking is moving wine from one container to another—usually from barrel to barrel or from barrel to tank.

But racking isn’t just pouring wine from one place to another. It’s a gentle process in which you stop before all the wine has been transferred so that any sediment is left behind. That sediment, known as lees, is made of dead yeast cells and grape solids that settle out of the wine. Racking is rather like decanting, but on a much larger scale.

Just like decanting, the process aerates the wine, so a winemaker has to make careful decisions about when and how often to rack. Racking helps clarify a wine, prevent unwanted fermentations (or malolactic conversions) and soften a wine’s profile. In some regions, like Rioja, multiple rackings tend to be a common part of the winemaking process. Winemakers working in a reductive style might avoid or minimize racking.

There are a couple of main ways to rack. There’s usually a plastic hose involved, and you can either use gravity to siphon the wine or use a gentle transfer pump.

You may have heard the phrase “rack and return” from your winery friend. That process, also called délestage, involves racking a wine, then returning it back to the tank over the cap. Racking and returning is similar to pumping over and punching down, and it helps manage the extraction of color, flavor and tannins.

If racking is so important in winemaking, why would your friend hate it? It can be a tedious, time-consuming process that requires a lot of attention to detail. I’m guessing that explains his ire.

—Dr. Vinny