Avoiding Oxidation

I made a stout a couple months ago and it smelt absolutely delicious. I was so eager to drink the first glass.
Upon transferring to secondary I offered myself a drink. Very watery - still confused how this came about, but not the problem at hand. It tasted great aside from the weak body.

Finishing, I ended up with a very small head space, but had quite a bit of splashing upon transferring... Quite a bit!

After bottling for 3 days I took a sample out and it tasted very metallic and I've been persuaded that it is indeed oxidation (the slightest 'wet cardboard' flavor as well - but not noticeable).

So I'm wondering if there is a solid technique when working with these dark stouts to avoid oxidation? (Does anyone know what the 'metallic' flavor actually arises from?)

Before anyone says anything

My water does not have a metallic flavor
I used no metal in the entire process except my pot which is brand new stainless steel.
The hops don't seem to contribute the flavor

Don't splash and create an environment where oxidation will be a possibility.

2nd on the don't splash. do you keg too? if so you can purge your carboys and such before transferring.

While the splashing was most likely the death nail, head space in the secondary didn't help. Should have some head space and you can't top it up for whatever reason, fill that space with an inert gas. But not just CO2. This stuff works wonders, as the argon settles on top of the beer.

http://www.keystonehomebrew.com/shop/wine-preserver-inert-gas-blanket-120-full-uses.html

One of the many things brewers can steal from winemakers!

I would give the beer some time; the oxidation could just be in your head at this point. On one of the BN sunday sessions, Gordon Strong described his bottling technique for NHC. He would carbonate the beer to a desired level in a soda bottle with one of those soda carbonators, and then pour the beer back and forth into the bottle. Obviously, he'd store the beer cold, but there would be a few weeks before the beer was judged, and he did pretty well. I think your oxidation would take more time to really show up. When I've had it in my homebrews, it's taken several months, or more than a year in the bottle to become obvious. I really just get a lingering aftertaste that is a bit raisin-y and cardboardish, and not all that pleasant after I realize what it is (it tends to coat the back of my tongue). I'm not sure about metallic flavors (sometimes contamination is described that way), but it may go away, or it could be due to another problem.

In any event, I'd skip the secondary. Let the bottle be your secondary. I bottle straight out of my primary (using one of those plastic german fermenters with a tap on the bottom or an auto-siphon with a valve at the end). It minimizes air contact, although it's always going to occur for a bottling home brewer. I add the priming sugar solution to each bottle with a syringe. It lets me play around, and use multiple sugar sources to prime my beer.

Thanks all.
Did not know argon was that cheap - that is crazy. I thought argon was on the rise (I'm a chemist).

And farmerted - good point with the aging. This beer is barely a month old and already has this taste, so something else may be the culprit. I really doubt its contamination though, but maybe... Its drinkable, but its flavor is short lasting, followed by well-water with a hint of beer in it. I did have this problem on my very first batch of beer as well - an oatmeal stout.

I am under the impression though, that aging it may help... even if its locked up in the bottle. I'll try another drink next week and see if I can notice a difference.

I'm dead against pouring out beer. Sometimes age can cure the taste, even if you end up with something completely different than you set out to brew. Throw it in a carboy, fill the head space, and come back in a couple of months.

The worst that could happen is you tied up a carboy. The upside is you could "gain" 5 gallons of beer you thought you lost.

When racking to bottling bucket or secondary,I have a tube on the spigot down half way round the other bucket,whatever so it doesn't oxygenate. Using gravity to fill from the bottom up. Draft magazine says of the metallic taste-Aromas or tastes similar to iron,rust,coins or blood. It's presance has a number of causes: rusty pipes or water,high malt roasting temperatures or staleness. Usually an off flavor. I got it from this link; http://draftmag.com/offflavors/

ya come to think of it i think that metallic taste can be somewhat mysterious as to it's source. I mean the obvious things are what unionrdr said from the link. I remember reading an article in BYO that said sometime it just happens even to really experienced brewers and the cause is pretty unknown. I believe the article was by Jamil.

Just a thought, but if the pot was brand-new that might be it.

Metallic- Check water for metallic ions. Reduce water salts. Check equipment condition for rust. Make sure stainless steel equipment is properly passivated. Fully rinse sanitizer. Try using RO water and add salts as needed.

Click to expand...

http://www.bjcp.org/faults.php


Also, sometimes chlorophenols can taste metallic. Try Campden.