Aeration Questions

twhite315@gmail.com · 03-13-2008, 04:46 PM

1. I need some ideas on how to aerate wort that is in a 14.5 Gal Blichmann fermentor without using a aeration stone.

2 Is there such a thing as over aeration with oxygen? Can this cause off flavors?

FlyGuy · 03-13-2008, 04:55 PM

1. What -- you can't just shake the heck out of that bad boy?

Seriously, some guys swear by a paint mixer or wine degasser hooked to an electric drill to 'whip' in some air. If you go with a paint mixer, you might try to find one that is stainless steel or relatively non-reactive.

Why don't you want to use O2 and a stone?

2. If you are aerating (not oxygenating), it is impossible to put in too much oxygen. Even with an oxygen tank and diffusion stone, it would be really hard (according to Wyeast).

twhite315@gmail.com · 03-13-2008, 05:01 PM

I want to eliminate the stone as a possibe point of infection. I am getting butterscotch or cooked vege tast in by brew.

FlyGuy · 03-13-2008, 05:14 PM

Quote:

Originally Posted by twhite315@gmail.com

I want to eliminate the stone as a possibe point of infection. I am getting butterscotch or cooked vege tast in by brew.

If you have a SS stone and silicone tubing, you can boil it or heat sterilize it in the oven.

Regardless, cooked vegetable and butterscotch off flavours are more commonly problems with your brewing and fermenting. The vegetable/cooked corn flavour/aroma comes from DMS, which is usually driven off by a strong rolling boil of the wort. I would look to your boiling technique a little more closely (keys are strong roiling boil for 60 - 90 minutes depending on the grainbill, uncovered [always], and a fast chill).

The butterscotch flavour can arise from an infection, but normally it is associated with a weak fermentation or a beer that hasn't been given enough time to age. Diacetyl is a normal fermentation product of the yeast, and typically it gets 'cleaned up' by the yeast during the conditioning phase. But underpitching or temperature problems can prevent this. If you rack the beer off a highly-flocculant yeast too early, it can cause these problems as well.

You might have known all of this anyways, but I'll mention it in case someone who wasn't aware of these issues also reads this post.

srm775 · 03-13-2008, 06:05 PM

Ditto on what Flyguy said. The butterscotch or butter flavoring is most closely associated with fermenting at too low of a temperature for the yeast or not leaving the beer on the yeast cake long enough.

The veggie smell/flavor is definitely DMS. Probably from not cooling quickly enough.

What are the brews that you're getting it with. For some ales, a slight amount of DMS is supposed to be there, like Cream ales. You'll tend to have more of a DMS flavor with beers that use alot of corn as an adjunct.

twhite315@gmail.com · 03-13-2008, 06:08 PM

I do a full boil for 90 mniutes with lid off and Fermentation is strong. at least the last batch had a good fermentation. I have a great wort chiller! It will go from 208 Degrees F to 69 Degrees in seven minutes. Is 64 to 68 to low of a fermentatation temp? All I am brewing right now is IPA EPA and AAA.