What are you brewing?

[nzbrewer]

Since this is the most popular thread on the RealBeer.co.nz forum I thought I would start it here just to see what happens

[denimglen]

I started doing the rocking thing. I thought I was getting enough aeration from letting the wort drop quite a way into the fermenter - It frothed up quite a bit but I don't think it was cutting the mustard.

Although I've never used this yeast or recipe before, with about 2 minutes of solid rocking and violent splashing my lag time for visible fermentation and the time for visible fermentation to stop was cut in half to what it usually is.

Apparently the aquarium pumps aren't that good from a little reading I did. The second best method is a good solid splashing for about 2 - 5 minutes. The best method would be pumping in pure oxygen through a stone. But this can be a little risky without a dissolved oxygen meter as it is possible to over aerate.

[Reviled]

I heard there is no such thing as over aerating, or that its pratically impossible to do in a home brewing situation?

[JoKing]

It's not over aeration that is the issue - it is over oxygenation. Anything over 20ppm dissolved oxygen can be a bit of an issue. I dont think you can acheive this with an aquarium pump: but you can with pure oxygen.

Too much O2 will result to overly vigorous fermentation and excessive yeast growth, potentially resulting in off flavors, particularly esters. Generally an Ale requires 8-12 ppm, and lagers 10-15.

[denimglen]

IIRC shaking for 2-5 minutes gives around 6 - 8 ppm and a pump and airstone for about 30 mins gives about the same. I think the max achievable (without pure O2) is about 8 ppm.

Will have a look around for the stuff I read and post up here for those interested.

[Barry]

Thought I'd add that you only need oxygen to achieve cell growth. You don't need it for dry yeasts, nor do you need it if you're re-pitching a big enough slurry.
If you have a fresh pack of liquid yeasts, or have made a fresh starter from one, oxygen is a good idea because you need those yeasties to multiply.
If you use an aquarium pump you should get a filter for that bad boy. Otherwise you're just pumping bugs from the air around you into your unfermented wort.

[JoKing]

If you are getting yeast activity within the 1st 12 hours, from a pitch of a white labs vial (or a smack pack) in a 500ml starter and your wort is <1060: your aeration is totally ample. A 6 hour lag time is the shortest you'd want. Let those mothers work at their own pace, the beer will tase better.

[Greig McGill]

*EDIT* Man, this is a really OLD discussion... I thought the posts in the search were recent. Silly Ning.

 

Was it this PDF from basicbrewing.com that I linked to ages ago?

 

http://media.libsyn.com/media/basicbrewing/AerationMethods.pdf

 

I'm also considering going to a stone and pump after advice from a certain Devilish (but not Impish) brewer, as I'm planning a big-ass barleywine this weekend, but I'm not sure where one gets a sterile air filter? Any and all advice appreciated.

[JoKing]

Go down to your mates place and grab a little oxygen bottle (for welding) and blast what wort for 30secs... done.

[Martin Bridges]

Pale Beauty - an American IPA-ish recipe

6.5kg Maris Otter
250g Wheat malt
60g NZ Fuggles @ 60 min
40g NZ Hallertau @ 30 mins
40g Motueka @ 15 mins
30g Motueka @ 5 mins
Will be dry-hopped with Riwaka
Safale US-05 dried yeast (2 packets, rehydrated). Pitched at 20 degrees
OG = 1.062, IBUs = 65

Cheers,

Martin

[Reviled]

Nice!!! Are you kegging this or bottling Martin? looks tasty!

[Martin Bridges]

It depends! If I can get my kegging setup ready in time it'll be kegged, if not it'll go in bottles.

Martin

[Reviled]

If you end up bottling can I swap you a bottle for something? And if you keg it, can I come round for a taste? :o)