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What is this?

I’ve had this happen for 4 all-grain batches I haven’t a clue what it is and how to prevent. I’ve never had it with extract I kept the same sanitation practices which i think… is pretty thorough . It’s a white film on the top and the one I have now is bubbling

That’s one of he scarier pictures I’ve seen. Looks like a Petrie dish.
I’ll guess that it is bad. I don’t have the experience to know…but mold? Bacteria colonies?

Looks like you need to work on your sanitation practices, particularly if this has happened 4 time in a row!
Give your equipment a good soak in PBW and use a good sanitizer like StarSan.

I’ve seen similar before and the beer was fine. Thieve a sample form underneath it. Smell it and taste it. I think it’s something that only grows on the top where oxygen is. The few times I’ve seen it was with long primarys. I like to get my beer in bottles or keg as soon as it’s ready anymore.

It looks alot like a Lactobacillius or pedio bacteria made its way into your batch. That is called a pellicle. See here: … le-237410/

Need to sanitize better…as was said above.

Looks like a pellicle to me. Have you tasted this one or the other batches?

I sanitized the hell out of my buckets and it made all the difference no sign of infection at all so i guess just soaking the buckets with starsan wasn’t enough. I made a stronger solution of starsan and rubbed it down with a sponge. The Scottish 60 schilling above tastes ok…but nothing like a Scottish Ale it’s waaay closer to that of a Belgian White

This could be acetobacter. Do you have fruit flies in the house / around the fermenter? The little buggers can crawl into the tiniest of gaps. You’ll typically see a bunch of them hanging around the fermenter if that’s the issue. The bacteria produces a vinegar-like sourness. Even if you sanitize really well, if these guys get in the fermenter they can still infect the batch.

Starsan is a great sanitizer, but the thing being sanitized must be absolutely spotless first. Starsan cannot penetrate soils (very much, anyway), so any visible grime must be removed prior to sanitizing. Soak the buckets in hot (140°) oxyclean or PBW solution, agitate and, if necessary, wipe down the walls/bottom with a clean soft cloth soaked in the same cleaning solution. It’s best not to touch the walls at all if you can avoid it, but some stains just don’t come off otherwise.

When they are clean rinse the buckets 3X with water and then use the standard concentration of starsan (1 oz/5 gal). Once the starsan has been in contact 1-2 min you can dump it out and fill the wort. It’s best to put your beer in the fermenter while its still wet from the starsan, don’t worry about a small amount of starsan foam.

Infection problems can also be caused by sluggish yeast, since when we boil wort we are not sterilizing but only sanitizing, so there’s always a small amount of contamination in the finished product. We just pitch enough healthy yeast to outcompete anything else and hopefully make a clean product.

Given that this happened 4 times in a row, you might want to get a new clean fermenter rather than risk the cost of ingredients on another failed batch. Plastic can be scratched and cracked and make nice little areas that are uncleanable and can harbor bacteria.

You could have some tiny or micro scratches in your buckets for bacteria to hide. That happened to one of my plastic carboys. Just about impossible to clean and sanitiz. Had to toss it out along with all my cold side plastic stuff (thankfully mostly just tubing). If its not your process its something in the equipment.

It looks like your beer was exposed to oxygen for an extended period. As long as it is not sour, rack beneath the surface sheen and you should be fine. I’ve seen that on beers fermented in buckets that have been opened for gravity checks or weren’t well sealed. I wouldn’t worry about it at all if it tastes ok.

Yes, I agree completely about how it might the scratches in my bucket. However I’ve done two batches now with the same buckets I think.(I own four 2 primaries two secondaries) and they turned out great with no signs of infections. BUT I didn’t keep very good track of which ones the beer was getting infecting in, but there’s a good chance they were the same ones. I will however buy some PBW and probably throw most of my tubing away and possibly my autosiphon.

I agree with beforesaid acetobacter theory. In my experience this does look like aceto. Lacto looks differently.

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