Inconsistent Carbonation

Some of my beer fizz over (to the point of emptying an entire bottle) when I open them.  Some don’t.  Now, this isn’t a batch vs. batch problem.

My stout, for instance.  Some of the bottles just explode when I open them.  Others are fine (and taste delicious).

Does anyone know why this would happen?  Why the inconsistency?

How do you carbonate/prime would be the first question?

How do you sanitize/clean would be a second (or arguably first) question.

If some bottles are perfectly carbed and others are gushers but none are every under carbed I would suspect contamination.

If some are undercarbed I would lean towards insufficient mixing of the priming sugar.

^^^^^^^^^ Beat me to my answer.

Or it could be that you are not mixing the priming sugar well. Either one could cause your problem.

Morticaixavier covered that.

My bad. I shouldn’t ever post until I have had at least one cup of coffee.

+1

I also believe you have:

A. Contamination — need better bottle cleaning and sanitation process

or-

B. Priming sugar is not evenly mixed into beer prior to bottling.

How do you clean/sanitize your bottles? What’s your process of adding priming sugar?

My thoughts too.^^^

I pour in the priming sugar solution while it is still quite hot after I’ve run about two quarts of beer into the bottling bucket. I’ll use at least 16oz h2o, on the thin side- this ensures the solution incorporates evenly and well. If you are waiting for it to cool and it is thick you’ll run into problems with the mixing.

Sanitation! Make sure your rinse your bottles well as you use them- store them upside down so all the water drains out and nothing can drop in like dust or whatnot or grow in there. I use the dishwasher on sanitize setting and bottle off the dishwasher. No mess.

But I have used starsan or iodophor and it works well. Baking bottles was where I saw breakage and infections.

+1 to everything Euge said plus a couple more recommendations. I use a sanitized spoon to gently stir the priming solution/beer mixture in the bottling bucket a couple of times while racking. I also leave my tubing a bit long and let it curl around the inside of the bottling bucket. This way when I rack over the beer swirls into the bucket and helps it mix with the priming sugar.

Thanks for the help, everyone.

To clean the bottles, I usually run them in the dishwasher (no detergent) right before I’m getting ready to bottle.  I open the dishwasher for the first time as I start bottling.  Is this not good enough?

I’m assuming I do have a sanitation problem, if that’s the common thread here.

Tubercle votes for insufficent mixing of the priming solution.

Are you using the sanitize setting on your dishwasher?

I would still give them a dunk in sanitizer after. It is quick and the dishwasher must have REALLY hot water to sanitize.

It’s probably more likely an infection, but inconsistently mixed priming solution is an easy thing to fix. I sanitize a long spoon and give the bottling bucket a few stirs every 6 beers or so.

I know we talk about changing one variable at a time, but in this case I’d tackle both.  Rinse all of your bottles right after you empty them, do the dishwasher thing as long as it gets hot enough (dunk in sanitzer if not), and make sure the sugar is well mixed in the beer when bottling.