Splish Splash

Got an email from a reader with a question about aeration and yeast. Any further reader input would be welcome…

Hey Scott,
Just found your blog,  while searching for the origins of the dark IPA.  I’m going to attribute it  to Greg Noonan just like every Vermonter should.  I’ve been trying to get  better with homebrewing and have been a little concerned with aeration of the  wort going into primary.  I’m a PhD student in biobehavioral neuroscience  so I get a bit anal about things, bear with me.  As a scientist I want a  specific value for dissolved oxygen necessary for a good fermentation, I find  that nowhere.  Some suggest a vigorous shaking of the wort, I’ve read of  aeration systems (access to medical 95%02, 5%CO2 so I’m tempted), and I’ve also  read many that like you suggested transferring the wort so that it is a bit  splashy and aerates “enough” (the scariest option for me as a scientist, I need  control!).  Is a good pour typically enough to provide enough oxygen for a  healthy ferment?

Enjoying the reading material you provide.  Thanks!

Hey Brendan, thanks for checking out the blog! Glad you’re enjoying it.

As you probably can figure out from my posts, I am NOT much of a scientist – I have no idea what kind of dissolved oxygen ratio would be ideal for optimum start-up. I have, for my entire brewing career (20 years) observed that pouring the wort into the fermenter and allowing it to splash well has been more than adequate. For a short while I used a counterflow wort chiller, siphoning the wort through copper into the bucket, and I am absolutely certain that there was not enough aeration occurring then – I had several batches that took days to start, and ultimately had off-flavors that one would associate with lag spoilage bacteria… Using the “pour and splash method” I usually get active fermentation within 4 – 6 hours, even quicker if I have built up a starter slurry…I don’t have my copy handy right now but I’d bet if anyone has quantified the oxygen content question it would be found in Greg’s “New Brewing Lager Beers“…
best of luck,