oxidation question?

[ChandlerBang]

What do you mean you don't use sanitizer or vodka in the airlock? What do you use? And yeah, I kinda think air sucking back into the secondary is kind of a big deal. Prolly not causing the same off flavor in every batch, hut something you would want to eliminate from occurring.

 

[tcbailey]

I found the same thing when I used to secondary. I did some reading and believe it is from a secondary reaction converting ethanol to acetic acid (vinegar), which happens with oxygen and warm temperatures. Two ways to deal with it - secondary in a fridge, or purge your secondary with CO2 before racking into it. I just gave up on secondary and simply do an extended primary, then right into the keg for cold crash. Never happened since. Also, throw a couple bags of ice in your tub, and your wort will cool down much faster. I did that before buying an immersion chiller.

 

[JLem]

Even if you keep filling the airlock, you should still be concerned about the suck back. Every time that happens, it is also sucking in air, filled with oxygen and bacteria and wild yeast.

The way to avoid suckback in secondary is to make sure you limit the headspace by filling it as completely as possible.

 

[maida7]

Or just skip the secondary and put the beer in a keg for aging.

 

[wittmania]

You may also consider using the S shaped 2 bubble style airlock instead of the three piece kind. It will allow "suck back" without draining the sanitizer back into the vessel and any air that comes through will at least have passed through sanitizer first.

 

[ChandlerBang]

You may also consider using the S shaped 2 bubble style airlock instead of the three piece kind. It will allow "suck back" without draining the sanitizer back into the vessel and any air that comes through will at least have passed through sanitizer first.

This doesn't make the air sanitary... And airlock is designed to let positive pressure out. If a vacuum occurs, either limit headspace or use a solid bung, or both.

 

[ChandlerBang]

I found the same thing when I used to secondary. I did some reading and believe it is from a secondary reaction converting ethanol to acetic acid (vinegar), which happens with oxygen and warm temperatures. Two ways to deal with it - secondary in a fridge, or purge your secondary with CO2 before racking into it. I just gave up on secondary and simply do an extended primary, then right into the keg for cold crash. Never happened since.

Interesting. I hadn't heard of this. Do you have a source? I always blast a secondary with co2 for a few seconds before racking anyway.

 

[kh54s10]

I would also eliminate cleaning with Cascade it has detergents and perfumes in it. Get some PBW or Oxyclean (the kind without scent).

Use sanitized water or vodka in the airlock.

I don't know if these have any effect on your beers but certainly would be safer.

IMO unless you get EXTREME amounts of air sucked through the airlock oxidation from that is unlikely. The oxygen is lighter than the co2 so it should not get to the beer. It would stay on top of the co2 layer. Infection is a possibility though. Using sanitized water or vodka would lessen the chance of this.

 

[pjj2ba]

I found the same thing when I used to secondary. I did some reading and believe it is from a secondary reaction converting ethanol to acetic acid (vinegar), which happens with oxygen and warm temperatures. Two ways to deal with it - secondary in a fridge, or purge your secondary with CO2 before racking into it. I just gave up on secondary and simply do an extended primary, then right into the keg for cold crash. Never happened since. Also, throw a couple bags of ice in your tub, and your wort will cool down much faster. I did that before buying an immersion chiller.

Ethanol can indeed be converted to acetic acid, and does require oxygen. However this is not a very common spontaneous chemical reaction. It is however common if you have some Acetobacter bacteria around (which is pretty common). This bacteria cannot survive in a oxygen depleted environment (fermented beer). However give it some oxygen and it will happily convert your beer to vinegar

Upshot is, having some oxygen exposure alone won't give you an acetic bite. You have to have contamination as well. Or if you have contamination (with acetobacter), just limit any O2 exposure and you'll be fine.

 

[dkbanjo]

One thing that strikes me after reading these responses is that my batch sizes have become a little smaller (4.5 gallons sometimes). So limiting the head space could be part of it, because I had a feeling that a lot suckback cant be good. Infection Could be the other part of it. For my next brew day, which wil be in a couple of weeks I'm going to to the following....
-clean vessels with oxyclean (we sell it at work).
-use sanitizing solution in airlock.
-get a two chamber air lock for secondary(so no sanitizer gets sucked back into vessel, just incase) or solid bung.
-replace all plastic parts.
-make an immersion chiller to cool wort faster(we sell soft copper at work).
-make my batch bigger to limit head space.
-and purge vessel with co2 before transfer.

This sounds like a lot, but it really isnt. I wish I could have a separate fridge for cold storage and more kegs, but space is an issue. I'm really excited to try these suggestions. If any one has any others I'm open to here them, otherwise, thank you everbody. This was a great first experience on a forum for brewing.

 

[JLem]

One thing that strikes me after reading these responses is that my batch sizes have become a little smaller (4.5 gallons sometimes). So limiting the head space could be part of it, because I had a feeling that a lot suckback cant be good. Infection Could be the other part of it. For my next brew day, which wil be in a couple of weeks I'm going to to the following....
-clean vessels with oxyclean (we sell it at work).
-use sanitizing solution in airlock.
-get a two chamber air lock for secondary(so no sanitizer gets sucked back into vessel, just incase) or solid bung.
-replace all plastic parts.
-make an immersion chiller to cool wort faster(we sell soft copper at work).
-make my batch bigger to limit head space.
-and purge vessel with co2 before transfer.

This sounds like a lot, but it really isnt. I wish I could have a separate fridge for cold storage and more kegs, but space is an issue. I'm really excited to try these suggestions. If any one has any others I'm open to here them, otherwise, thank you everbody. This was a great first experience on a forum for brewing.

Just make sure you leave enough headspace during primary fermentation - otherwise you'll end up with a giant mess. It's just the secondary where you need to match the size of your vessel with the volume of beer. I brew 4 gallon batches and, if I use a secondary, I rack to a 3 gallon glass carboy. Headspace is practically non-existent and suck back is not possible.

 

[ChandlerBang]

Sounds like a good plan.

 

[dkbanjo]

Definitely, My primary is 6.5 gallon and my secondary is 5.

 

[tcbailey]

Interesting. I hadn't heard of this. Do you have a source? I always blast a secondary with co2 for a few seconds before racking anyway.

Chandler, this is the old "wine into vinegar" conversion, but with beer instead. I don't know if that was the reaction that happened in my case, but it definitely involved oxygen (I knew I was incorporating O2 since I didn't have CO2 to purge the secondary), and I knew the temp of secondary was too high, since I don't have a lagering fridge (yet). The resource was Google, and I stumbled on a website explaining the conditions for the reaction, and it sounded plausible that my conditions were perfect. It was so severe with one batch (I forgot I left it in secondary) that I had to dump the entire thing. A few times I noticed the really small bubbles after I transferred to secondary, immediately siphoned to keg, and drank the beer with a slight off taste. Now I only do primaries and straight to keg, and don't get any of this effect/flavor. I will soon have a lagering chamber and will go back to secondaries the right way...

Hope this helps.

Todd