Too much oxygen

I have done a couple batches of beer that had an OG of around 1.070 and then are stalling out during fermentation. One has gotten stuck and 1.050 and one got stuck around 1.020. Both batches were 10 gallons and were fermenting in carboys that were 6 and 6.5 gallons.

My question is, was that too much oxygen for the beer during primary? I didn't do a starter which is something that generally helps the yeast tear through my beers and the last batch I did I have been putting my ten gallons into two 5 gallon carboys and using blow off tubes, and those seem to be fermenting along just fine.

- Alex

What yeast are you using and what temperature are they at? Over oxygenation will cause rapid yeast growth and esters, but not a stalled fermentation.

I used a Belgian White yeast and an American ale yeast. Both I believe were stilling around 65-70 range.

- Alex

I've oxygenated the heck out of things, and never had problems before. I doubt it's from too much oxygenation.

acleanthous said:

I have done a couple batches of beer that had an OG of around 1.070 and then are stalling out during fermentation. One has gotten stuck and 1.050 and one got stuck around 1.020. Both batches were 10 gallons and were fermenting in carboys that were 6 and 6.5 gallons.

My question is, was that too much oxygen for the beer during primary? I didn't do a starter which is something that generally helps the yeast tear through my beers and the last batch I did I have been putting my ten gallons into two 5 gallon carboys and using blow off tubes, and those seem to be fermenting along just fine.

- Alex

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Your phrasing doesn't really make sense to me. Did you use pure O2? If so, for how long? What's the reason for thinking there's too much O2? It sounds almost like you think splitting into multiple carboys is some sort of benefit or something. I don't really understand what point you're trying to make here exactly.

Make a starter and you'll be fine. I make a 2 liter starter for around 5.7 gallons and make higher gravity beers a lot and never have a problem. You said you've made starters before but not for this higher gravity beer? Again, the phrasing is a bit hard to follow. Higher gravity beers require a larger starter than lower gravity beers so making them for your other beers then skipping making a starter for this bigger beer is backwards.

If you pitch a nice, healthy starter they're finish the job for you.

Not enough information but you're suggesting you did 2 x 1070 worts without starters.

Was the yeast a single smack pack or dried yeast or what?

Underpitching sounds like the problem to me.

Are you asking if there was too much oxygen on top of the wort since it was in larger carboys than usual? If so, that shouldn't have caused a stall.

Your problem is not in the fermenter size. I ferment 5.25 gallons in 6.5 gallon buckets everytime I brew. I've had my fermentation stall out at 1.020 twice in about 30 batches but that was most likely because I didn't have good aeration before pitching the yeast. 1.050 seems incredibly high for a beer to stall. I'd say your yeast pack was a dud.