Questions about aeration

[tegeberg]

Hi guys

I recently finished my first brew, a bitter IPA. Though the brew is certainly drinkable there are some slight of flavors. I wonder where they came from (bacause I want to improve this naturally) and I believe one of the culprits could be aeration, as I had a bit of trouble through the process, especially at bottling time.

So my questions are:

1. How would aeration damage typically taste? My two main culprits are aeration and a high fermentation temperature. How would these two normally manifest themselves in the beer?

2. How much does it actually take for a brew to become noticeably damaged from aeration, given that I am not a connaisseur at all and probably won't taste or notice minor things? I had a fairly smooth transfer to secondary but did have to move both primary and secondary a few times during the process "splashing" the beer around a little bit in the vessels. Should that be a problem?

At bottling time I used a bottling wand which got "stuck" and did not stop the flow quite a few times. This caused me to quickly move the wand from one bottle to another in an afford to not spill too much. Could this be a source of serious aeration?

Thanks a lot for all your help!

/Thomas

 

[SenorPepe]

Hey Thomas, take my advice with a grain of salt but I was worried about one of my batches that I oxidized the hell out of it so I looked into it a bit. First thing is it would probably help to know how long it's conditioned and the ABV. Higher ABV brews won't suffer as badly, or at least as badly as quickly, and for the most part you won't taste oxidation at all until a while into conditioning (how long, I don't know but I'd stab in the dark that in most cases it would be a month at the least?) I haven't tasted any really oxidized beers so I don't know if it comes on slowly and subtly or not but once it's good and oxidized you'll know about it. People seem to describe it as wet cardboard often. What tastes are you picking up?

 

[amarilloarmadillo]

Hey there,

I'm new here on HBT but have been brewing for a 3 years and can give you some insight.

Usually aerated beer manifests itself in a cardboard kind of taste, which can also be described simply as stale beer.

Not sure what you are tasting but you should know that light and temperature also affect your beer during and after fermentation quite a bit.

How high of a fermentation temp are we talking here? Usually if I make an ale and have the ac on in my place around 72 to 75 degrees my ale still turns out great. Usually a higher ferm temp will make some really fruity esters on the yeast side of the beer, depending on what strain was used.

If you could describe the off flavors more I might be of more help.

 

[Homercidal]

Typically, high temps will cause off flavors, while oxidation, from aerating wort after fermentation causes a stale cardboard like flavor.

How much depends on your personal tastes and how long it is from introduction of air and tasting.

The best method of bottling would be to add CO2 to the bottle before filling and cap on the foam. This is not always easy or possible for everyone, so I think good practice is to just be careful and try to limit the amount of "splashing" you do.

When you fill a bottle, there is a good chance that there is residual CO2 in the beer, and the process of filling a bottle may release some of that, causing foam. If you can put the cap on and seal it before air can get it, you're probably fine.

IMO most people will be ok if they do not have a hole in their bottling system that allows air in, as long as they are fairly gentle that is. Moving a vessel is not a problem since there is blanket of CO2 over the beer and so little chance of Oxygen getting in contact with the beer. Stick you head in a fermenter after it's been going for a bit and take a sniff. you will painfully find out how much CO2 is on top of that beer!

There are two types of bottling wand valves. one is known to work better than the other. Maybe try the other one? I think the one I usually use has a spring in it. Can't remember.

EDIT: Oh yeah, forgot to say that you should probably try to get your fermentation temps down to mid 60's of you can. I think a clean ferment is more important than worrying about aerating your beer.