The Cleanup Crew

Like any gathering attended by a billion of your closest friends, yeast parties (aka fermentation) tend to leave a mess. But with plenty of time, yeast in good health make like stealthy teenagers and clean up before their parents get home. No harm, no foul and no trace of the wild, rollicking times that came before.

All fermentations are messy—even when you’ve raised rugged yeast and pitched perfect populations with optimum oxygen. While greedily snacking down on sugars, yeast produces ethanol and CO2 and spits out flavorful esters and phenols, along with acetaldehyde and diacetyl—two things we don’t want in our finished beer.

In a well-managed fermentation with healthy yeast, appropriate temperatures and sustained contact times of about one week, the cells will sweep through the green beer and begin to consume the highly noticeable chemicals responsible for green apple (acetaldehyde) and buttery (diacetyl) flavors and aromas. Acetaldehyde is converted into ethanol while diacetyl is transformed into butanediol. One is fun, the other is odorless.

During cold weather months this cleanup cycle can run into a bit of a wall as yeast flocculates and hibernates at the tank bottom. Or maybe you’re in a hurry or your yeast isn’t super-healthy. No matter what the cause, you’ll want to finish the cleaning process. If your beer is still on the yeast, rouse it and warm it up. If not, properly rehydrate a pack of dry yeast and pitch it. Wait a few days and all of your cleanup should be done!

TUPELO WEIZEN BRAGGOT
This massively honeyed beer was inspired by the intensely spicy flavors of tupelo honey. The idea was to build a big wheat beer that smelled like a clovey Hefeweizen. But when I first tasted it… Diacetyl City! So I vented all the CO2 from the keg, added fresh yeast and waited a week before crashing and transferring it to a new keg. Fortunately, this step saved all five gallons of an expensive project.

For 5.5 gallons at 1.120 OG, 27 IBU, 3.4 SRM, 14% ABV

Malt/Grain/Sugar
6.0 lb. Wheat malt
4.0 lb. Pilsner malt
0.5 lb. Carapils malt
10.0 lb. tupelo honey

Mash
Rest at 154°F for 60 minutes

Hops
2.0 oz Tettnanger (pellets) | 4.3%AA | 60 minutes

Yeast
WLP001 California Ale yeast cake.

Directions
Mash the grains and boil the wort as you would normally. Add the honey at knockout to avoid driving off the aromatics. ■