If you feel like your beer has turned out a little flawed and you are kegging, some cold conditioning (also know as lagering) can sometimes mitigate flaws before serving. Flaws that can be corrected a bit are usually ester (fruity and solvent like), sulfur, and tannin (harsh bitterness) based. Acetaldehyde (green apple) is easier to remove at room temperatures with yeast present. If you are bottle conditioning this is a different story because you still need to keep the bottles room temperature and the yeast in suspension will continue to mop up your dirty work. Remember, if your beer is infected, or just generally undrinkable even after a month on the yeast, there might be no help and you’re looking at some process issues, but hey, it’s always worth a shot.

Traditionally lagering was done at cold temperatures in beer cellars or in caves. Today with refrigeration there are lagering tanks in breweries. The beer is stored for an extended period of time from a few weeks to months. During this time proteins, phenols, tannins, and other undesirable compounds will drop out of the beer leaving it clear while smoothing the flavor. Traditionally just lager style beers using bottom fermenting yeast received cold conditioning but these days almost all beers at production level receive at least a cold crashing to help clear the beer, and of course with refrigeration, we are looking at temperatures at or even slightly below freezing.

Ideally you would like to get your beer as cold as possible. Since we are assuming you are kegging the old set it and forget method would be employed to carb up the beer while setting your fridge to the coldest setting as possible. I find that setting your regulator to 25 psi for one day and then turning it down to serving pressure for a few more days will get your beer carbed up quickly. Using the crank and shake method you can get the beer carbed in a day. But really you are not getting the benefits of lagering if you drink it after one day of being cold.  With set and forget you just set to serving pressure, so lets say 12 psi, and check it out after a week to see if it’s acceptably carbonated to your taste. Meanwhile you’ve been cold conditioning your beer for a week.

Even a week of lagering can improve your beer drastically.  The following is a great example. Fearing a yeast stall out when temperatures in my garage dropped into the 30s where I keep my fermenting fridge, I turned off the thermostat. Big mistake. Beer that was 68 ramped up to 76 overnight even in near freezing conditions! My IPA turned into a fruit bomb. After moving to secondary and dry hopping it the flaw seemed even worse when I transferred to the keg. I usually pull 3 – 4 ounce samples while I’m carbonating to check the levels. Day one of course before any conditioning the beer tasted like bubble gum. Day three the beer had mellowed to a slight taste of sweet orange rind. Day five just a trace of solvent with almost all fruitiness gone while the dry hops were poking through. Day six no traceable fruit flavors or solvent while the Munich malt and hops were now center stage. Not even a week of lagering had smoothed this puppy out!