Aeration and contamination

I am now preparing to start my third batch and have come to learn quite a bit so far about the process of brewing. I know I have a long way to go. Here is something that has been bugging me though. We seem to take great pains to keep contamination from outside air out of our brew. But then once we get the fermenter filled with wort we aerate the wort, and it seems that a common way to do that is to shake the wort to incorporate the available air that is in the environment. Are we not just incorporating the contaminants from the air into the wort?

Not really. If you are shaking I would suggest (assuming a plastic 6.5 gal bucket) cover the hole where the airlock grommet is with a little piece of sanitized saran wrap then shake the living crap out of it for about 5 minutes. I went with a oxygenation stone that used pure oxygen. It costs more but saves you from having to shake it for so long. In a batch with average OG I run the oxy for 30-60 seconds. That said I can not see or taste any difference in the batches I aireated by shaking compared to the ones I used oxy injection.

When shaking/aerating I just make sure I sanitize my finger (usually been in and out of sanitizer a dozen times by then anyway) and hold the hole with it.

I also use a wine degasser from time to time and that creates a vortex that sucks in all kinds of air… which is what you want, but yeah, I could see some nasty stuff getting in there too. Having said that, I’m close to brewing batch number 100 and I’ve only had one infection. And that infection was because the lid blew off a bucket so the primary was open for a day or two while in a mini-fridge which honestly wasn’t that clean.

Don’t worry about it. Shake, mix, aerate, whatever… your beer will be fine.

:cheers:

That air (with questionable contaminants) was in the carboy before you even filled it up. Shaking it up isn’t really increasing the risk anymore.

I’m admittedly still new to this hobby but one piece of advice I will give you is: don’t worry too much about infections. You’ll start questioning everything you do. Just be diligent in sanitizing everything that touches your wort directly post boil and follow best practices.

[quote=“mattnaik”]That air (with questionable contaminants) was in the carboy before you even filled it up. Shaking it up isn’t really increasing the risk anymore.

I’m admittedly still new to this hobby but one piece of advice I will give you is: don’t worry too much about infections. You’ll start questioning everything you do. Just be diligent in sanitizing everything that touches your wort directly post boil and follow best practices.[/quote]

Sound advice.