Pesky Infection

[Travestian]

This may be a little long so please bear with me. I've had an issue with infections showing up AFTER I bottle lately.

I got my first bottle bomb from a Belgian Double that was given to me in a carboy. It had been bottled for nearly 4 months when the first one went off. I never noticed any off flavors with any of the ones I drank before the first bottle bomb. But after the bottle bomb I popped caps off the rest and they are foamed like mad. No pellicle in the bottle or anything.

About 6 batches go by with no problems. I still have some of the beers from some of these batches and they show no problems.

4 batches ago I had a sweet stout that I had to mix the lactose into after it finished primary fermentation. I sanitized and used my wort stir wand (all plastic) to mix it well. The other issue with that batch was the lack of an airlock. I used sanitized aluminum foil over the neck of the carboy. I bottled with no signs of any infection. Taste was normal. No pellicle (due to no oxygen yet I suppose). It was about a week later when I checked on one of the bottles that I noticed the white pellicle in the bottle. I dumped the batch.

So it looks like we have our smoking gun right? Well, before I did any other bottling I changed my bottling bucket, hoses, autosiphon, and bottling wand. I haven't used the wort stirrer since then either.

I bottled 2 batches just over a week ago and I noticed the same pellicle in each one in the bottle. Pictures are below. One was taken with the flash. One was without.

I can't think of anything that is common with the batches before and after bottling equipment replacement. I've got two batches fermenting right now that have plans for a competition coming up. Any ideas on what I should be doing differently?

 

[jiggs_casey]

When you changed out your bottling bucket, did you change out all the associated spigot, tubing, bottle filler, etc?

 

[fnord]

I'm just going to ask some questions to see if it might help find the culprit.

What type of sanitizer? Did you mix up new sanitizer?

How do you sanitize the bottles?

Any idea if they any bottles are the same bottles from the sweet stout, and if so how well did you wash them? Is every bottle of the last two batches showing a pellicle, or just some?

Are you bulk priming or using carb tabs?

Did you bottle the two batches back to back, and if so did you clean & sanitize between them? Also if so, what are the two batches and which did you bottle first?

Did you leave an offering for the beer fairies? https://www.homebrewtalk.com/f39/apparently-i-have-evil-gnomes-stealing-bear-out-my-primary-187905/#post2180189

 

[Travestian]

When you changed out your bottling bucket, did you change out all the associated spigot, tubing, bottle filler, etc?

Yes everything was changed out associated with bottling.

What type of sanitizer? Did you mix up new sanitizer?

How do you sanitize the bottles?

Any idea if they any bottles are the same bottles from the sweet stout, and if so how well did you wash them? Is every bottle of the last two batches showing a pellicle, or just some?

Are you bulk priming or using carb tabs?

Did you bottle the two batches back to back, and if so did you clean & sanitize between them? Also if so, what are the two batches and which did you bottle first?

Iodophor. Same sanitizer was used to sanitize all the bottles for the last two batches which WERE done back to back. I use a vinator to sanitize shown here: http://www.northernbrewer.com/shop/...eab33525d08d6e5fb8d27136e95/i/m/image_515.jpg

I rotate bottles so much and have so many empties that it is possible but not likely that the bottles are from the same batch as the sweet stout.

MOST but not all of the bottles are showing the pellicle.

Priming is done in bulk using corn sugar boiled for 5 minutes in 2 cups of water then chilled.

Even though the last two batches were done back to back I cleaned and resanitized everything same as I did for the first batch.

No offering for the beer faries

 

[jiggs_casey]

It seems odd to me that a pellicle would form in bottles that were capped. I would think that as soon as pressure starts to build, you would be in the clear. Unless the bottles were filled and left out for an extended period of time before they were capped. Maybe the capper itself needs to be replaced?

 

[Travestian]

It seems odd to me that a pellicle would form in bottles that were capped. I would think that as soon as pressure starts to build, you would be in the clear. Unless the bottles were filled and left out for an extended period of time before they were capped. Maybe the capper itself needs to be replaced?

Bottles get capped about 3 minutes after they get filled. The caps I use are all the oxygen scavenging ones and from different manufacturers. They all go into the iodophor solution before capping. Not sure the capper would be any possible source of infection.

 

[fnord]

Well I'm petty much stumped. Maybe try starsan for a batch or two.

I only used iodophor for a few batches before switching to starsan, but it was about 6 months before I ever saw mention that once diluted iodophor can't be stored and reused from batch to batch. I was fortunate in using month old dilution without ill-effect a couple of times.

This is just my opinion, but I don't feel as good about iodophor through a vinator as I do starsan. The way I see it the foaming and surfactants in starsan increase contact time & contact area compared to iodophor having more of a flow and possibly following just a couple of flows out of the bottle. Though the more think about it the possibility of it being infections in the bottles themselves seems pretty unlikely.

 

[jiggs_casey]

My thinking was that maybe the crimper on your capper is beginning to give out, not giving you a good, airtight seal. I could be wrong but, oxygen needs to be present in order for a pellicle to form. If you're using oxygen absorbing caps, I can't imagine that the little insignificant amount of space left at the top of the bottle when filling would even matter.

 

[pdxal]

"I could be wrong but, oxygen needs to be present in order for a pellicle to form."
Brett and, I believe, pediococcus need oxygen, but lactobacillus does not.
OP, I wonder if you need to clean and sanitize your bottles better. Sounds like the culprit if you have changed out bottling gear, sanitize it right before use, boil your priming sugar, and sanitize your caps.
IMO you should try the star san, or use the dishwasher on heat dry to sanitize via steam/above boiling temps.

 

[flars]

I agree with pdxal that the bottles could be the source of the infection since most but not all of the bottles are showing the pellicle. The bottles could contain dried gunk or are being infected during the bottling process.

Inspect a sample of the empty bottles you still have on hand. Look into the bottles with a strong light coming from the side against a white background. Look for any dark specks or a dark ring at he base of the bottles.

The length of time between filling and capping the bottles could allow airborne bacteria to settle in some bottles. Is there any sort of air movement where you are bottling? Air movement could be from people moving in the area or air conditioner fans.

 

[mark7347]

Also, oxygen absorbing caps are liquid activated, so exposing them to iodophor prior to capping renders their absorption tendency useless, though I doubt that's your smoking gun here.

 

[Hello]

At this point I would recycle those bottles and get new ones. I realize you could scrub, boil, sanitize, but I would just trash them all.

There seems to be nothing left to change. Also, why did you not use an airlock on one batch? Get another bung and airlock. Foil works I guess but I think that could give nasties a chance to enter in through the holes in your foil.

 

[Beernik]

I had infected bottles. I thought I was getting them clean after using but there was still gunk in the bottom. It ended up infecting parts of three brews before I figured out it was in the bottles.

After you empty the infected ones, see if you can rinse them clean. If you can't, toss them. Maybe toss them anyway.