Problems with over carbonation

Maybe the scale he is using for weighing out the sugar is off. Maybe he is bottling too soon.

Temp has nothing to do with overcarbing. The yeast will only use the sugar available. The only answer, other than infection, is that there is too much sugar.

 

Is he checking for a stable hydrometer reading over several days to ensure that fermentation has indeed finished?

 

Are the bottles cold when he opens them?

 

Top 10 Reasons Why Bottle-Conditioned Homebrew Will Gush:
1) Bottling too soon.
2) Too much priming sugar.
3) Infection.
4) Shaking bottle before opening.
5) 1 and 2
6) 2 and 3
7) 3 and 4
8) 1 and 3
9) 1 and 4
10) 2 and 4
11) All of the above.
12) None of the above.

 

The other possibilities are that he opened the bottle too soon such that the CO2 had not been fully absorbed, and/or that he'd benefit from chilling the beer a few more days before opening. That said, I've had several random gushers, and I can rarely pinpoint the issue.

 

Maybe try using brand new bottles?

Check all the equipment post ferm..Lines, bottling bucket, etc..

How far up on the bottle is he filling them?

 

Other than echoing what's already been said, I'd say "is he using a scale to weigh the sugar, and if so, how much is he weighing out?"

If he's using a measuring cup (or anything other than a gram scale), that's the likely culprit. If he's using a gram scale, how much is he using? I usually use 1 ounce (28 grams) per gallon, and that's on the high side. However, this much sugar can result in over-carbonation. I use the little bit extra because my beers get drank fast and don't sit around long enough to be over-carbonated.

More typical is 4 oz (112 grams) for 5 gallons. This should produce ample but not over-carbonation.

Of course I mean CORN sugar. Table sugar is different. I don't know the weights for table sugar, but there are sites where you can get such information. Also, if your final bottling volume is less than five gallons, you need to adjust your sugar for that as well.

 

No if fermentation is finished and he bottles they will not be overcarbed. Many people subscribe to the method of getting the same hydrometer reading 3 days apart for determining fermentation is complete.

Flavor development and cleaning up fermentation byproducts is a differerent story.

edit: It may be worth mentioning different yeast strains finish fermentation differently. A generalized example would be Belgian strains. They start like gangbusters but take forever, sometimes on the order of weeks, to finish the last few points. WY3711 also takes weeks to finish even though it looks like nothing is happening. I guess my point is that you have to get to know the strain you are using and how it behaves.

 

Opening the bottle too soon would not cause gushers.

 

I used to get random gushers, which I attribute to infections in the bottle. After a couple instances of opening a beer in my neighbor's kitchen, I decided to be a better diplomat for homebrewing and started meticulously washing my bottles. Rinse thorougly after pouring. On bottling day, scrub with bottle brush and oxyclean. Triple rinse with three volumes of hot water. Submerge completely in starsan so as to fill entire contents. Place on sanitized bottle tree until bottling operations are ready.

To further minimize randomness, dissolve sugar ~1.5 cups of boiled water. Transfer beer to bottling bucket and pour sugar solutin, gently stir to mix. Wait 15 min to allow sugar concentration to equilibrate throughout entire beer volume. Bottle.

 

If it's the entire batch that gushes, and it sounds like it's multiple batches, then its probably something other than an infected bottle (although it could be an infected siphon hose or something that impacts the whole batch). So quite possibly it is something to do with the way you are priming. Batch priming, like pweis909 described, works a treat although I'd tend to heat up a couple of cups of the beer to dissolve the sugar rather than water so as to not dilute.

In saying that, I've never had an issue with over carbonation using carb drops...except with ginger beer!

 

OK. Early on I had 2 beers that really ended up being Over carbed. The only ones I ever drain poured.
as it turns out I was measuring my sugar well. Temp was fine. No infections. Mixed in well.

The issue I found out is I was racking to a glass carboy for secondary fermentation and I was ending up with less than 5 gallons. There are no gallon lines on carboys like on buckets. I did not have enough beer!

Once you add your boiled sugar to your bottling bucket you are committed to that much sugar. If you think you have 5 gallons of beer and end up with 4-4.5 gallons you get over carbed

That is what happened to me twice until I figured it out. Make sure you know how much beer you are racking to your bottling bucket.