[gus55]

I bought Anniversary IPA from Austin HB, OG was 1.049, used US-05 yeast, I saved from my last batch. Started it with 1 cup of water and 1 cup of corn syrup, it took off and foamed over like mad. Temp is controlled at 20C. Still a layer of foam on top and bubbling once every 30 seconds or so. Its been 4 weeks and 2 days now. Mine usually finishes in 2 weeks, never had this happen before. How long can this go on?

[Stevie]

Have you taken a hydrometer reading?

[majorvices]

Don't count bubbles, thats just co2 coming out of solution and can happen for weeks. Layer of "foam" is most likely just yeast. Some strains (low flocculating ones) can remain on surface for weeks after fermentation is mostly finished. Lightly swirl the fermentor and that top layer should fall back into the beer.

As mentioned above, take a hydrometer reading. two readings that read the same after 2 or 3 days apart is how you know you are done.

[gus55]

Don't count bubbles, thats just co2 coming out of solution and can happen for weeks. Layer of "foam" is most likely just yeast. Some strains (low flocculating ones) can remain on surface for weeks after fermentation is mostly finished. Lightly swirl the fermentor and that top layer should fall back into the beer.

As mentioned above, take a hydrometer reading. two readings that read the same after 2 or 3 days apart is how you know you are done.

O.K., Thanks all, will try those things.

[denny]

Also, don't make a starter for dry yeast.  It's unnecessary and can be counter productive.  And when you do make starters, use malt and not corn syrup or sugar.

[ynotbrusum]

+1 to no starter for dry yeast - rehydrate, at most.  Extra handling could also have allowed an infection to be picked up - pellicle versus krausen?  You should be fine, though, just wait for consistent gravity readings before bottling.

[majorvices]

+2 - missed that part.