New BYO/BBR experiment
James Spencer and I are happy to announce the next in our series of Brew Your Own/Basic Brewing Radio collaborative experiments. We have two experiments this time, and you can participate in both (or either) by simply brewing a single batch of beer.
Experiment 1 -- How does trub in the fermenter affect your beer?
For homebrewers who use immersion chillers, after boiling and chilling wort, they must transfer it to their fermenter. (If a plate chiller or counterflow chiller is used, chilling and transfer happen simultaneously.) Some homebrewers try to minimize the amount of trub (protein, hop material and other "gunk" at the bottom of the kettle) that gets transferred and just rack clear wort. Others, thinking that the yeast may reap a nutritional benefit from some trub carryover, rack some trub to their fermenter along with the wort.
In our collaborative experiment, we want to test if beer made from clear wort vs. wort with some trub in the fermenter can be distinguished. And, if they can, we want to find out what the differences are.
For any homebrewer who wants to participate, the experiment is simple -- all you need to do is brew one batch of beer and ferment equal amounts of wort in two identical fermenters. After boiling and cooling, whirlpool the wort and let the trub settle. Transfer half of the wort to your first fermenter, taking care not to pick up any trub. Transfer the rest of the wort to the second fermenter, carrying over a substantial amount of trub. (It's up to you to decide how much, just write down an estimate when you do. For example, "half the trub" or "2 quarts.') If you have a plate chiller or counter-flow chiller, you will need to let the wort in one of the fermenters settle, then rack the clear wort into another fermenter.
Aerate both worts and pitch the yeast, taking care to treat both of the trails exactly the same. Label the carboys "clear" and "trub" and collect the following data:
OG of the wort (specific gravity)
Time until each carboy started fermenting (hours)
Time until each carboy stopped fermenting (hours)
Note any differences in the appearance of the fermenting beer during and after fermentation (take photos and send them in, if you wish)
FG of the wort (specific gravity)
Note any differences in appearance (including color, clarity or foam height/retention), aroma (including overall intensity as well as differences in specific characteristics) and flavor (hop bitterness and flavor, malt character and any other identifiable trait) in the finished beer -- if possible, get a friend to help and do the tasting blind (or double blind, if you know how to arrange that)
The experiment data collection forms will be posted at basicbrewing.com soon. The deadline is February 20th. While you're doing this experiment, try the second one, too.
Experiment 2 -- How stable is your wort?
This one is simple. It is called a forced wort test or wort stability test and is a way of assessing the level of contamination in your wort.
To perform a wort stability test, do the following: Near the end of your brewday, take a small glass jar with a sealable lid and sanitize it by boiling it in water for about 5 minutes. Let it cool and wait until you are ready to transfer your wort to your fermenter. During the transfer, collect some chilled, un-aerated wort in the jar and cover loosely with the lid (don't seal the lid). If you use an in-line aerator, shut if off just prior to collecting the sample, then restart.
Store the wort sample somewhere warm -- ideally around 80 °F (27 °C) -- and shielded from strong light. Check every 12 hours (or more frequently) and see when the first signs of fermentation are visible (usually as a spot of foam on the surface of the wort). Once you see evidence of fermentation, smell the wort and note the aroma. (If you feel brave, you could taste it, but I wouldn't recommend it. It won't hurt you, but it likely won't taste good.)
If you see fermentation within 24 hours, your wort is seriously contaminated. Your beer will likely exhibit off aromas and flavors. If you see fermentation in 48 hours, it still contaminated, but not as much as in the previous case. Your beer may or may not be overtly sour or phenolic (or show other signs of bacterial contamination), but it will likely be suffering in some way. If the wort is still clear at 48 hours (at 80 °F), your level of contamination is not likely to be a problem and your beer should smell and tast fine. If your wort is still clear at 72 hours, your wort is very clean.
For our experiment, report the following data:
Temperature the sample was incubated at (°F or °C)
Time when first signs of fermentation were evident.
Assessment of aroma of wort sample
You really should perform a wort stability test every once in awhile just to keep tabs on the effectiveness of your cleaning and sanitation. You can do this test even if you don't participate in the trub experiment.
So get brewing homebrewing scientists!