Understanding racking and lees is an essential part of the wine making process. Racking is usually done 2-4 times prior to bottling. Fermentation causes dead yeast and particles in the juice to fall out. Both of these end up on the bottom of your bucket or carboy and looks like sediment.
What is racking
New winemakers are often confused about what racking is and why it is important. Some even think that racking is the same as bottling. It isn’t. Simply put, racking is siphoning wine from one container to another container. Simple, right?
Why racking is important
Leaving sediment behind is the main purpose of racking. If you come from a beer brewing background, some brewers like to leave their beer on the trub (the equivalent of wine lees). In wine making, it’s undesirable to leave the wine on the lees for long. Leaving the wine sitting on top of the lees can (and does) impart unwanted off-flavors in your wine.
A secondary reason, yet still very important, is that racking helps the wine to clear. A clear wine is important for presentation, nobody wants to drink a cloudy wine.
When to rack
If you’re doing a wine kit, the instructions have a set schedule for when to rack your wine. As I’m sure you know, we’re big fans of wine kits around here for new wine makers.
For wine making that isn’t a kit, a typical racking schedule starts like this: 5-7 days after fermentation starts, do the first racking. A lot of lees will be present within the first week or so.
Rack again when fermentation has completely finished (as determined by hydrometer readings, you are taking readings, right?).
A third racking is done after the wine has cleared. At this point, there will be only a small layer of lees in the bottom.
When bulk aging in carboys, additional rackings will be needed. Typically, when I do bulk aging, I check weekly to see if any lees are present. If so, I rack when there is enough to warrant it. Often, there will only be a very thin layer after weeks of bulk aging.
Pro Tip: It’s possible to rack too many times. Racking exposes your wine to oxygen and as we’ve talked about before, too much oxygen exposure will ruin your wine. Before you rack, be sure that it’s really needed.
Racking and lees can seem like a confusing topic to new wine makers. But it’s really straight forward when explained. Remember this: keeping your wine on the lees for short times will result in better tasting wine with less off flavors.