My friend is having a terrible time getting the proper carbonation in his beers. They are absolutely great beers, but it seems that they are either flat or overcarbonated. Any suggestions?
How is he calculating how much priming sugar to use? This is a good carb calculator he can use for reference. http://hbd.org/cgi-bin/recipator/recipator/carbonation.html
This is a trick question, right? The obvious answer is to keg your beers. Thanks to the laws of Physics, carbonation is always dead on. No surprises as long as you follow the rules (no room for impatience). But that's probably not the answer you were looking for. One of the more common issues is measuring the sugar by volume rather than by weight. This is kind of a crap shoot. There's no way to be sure exactly how much sugar you're using if you use volume. The other biggie is not mixing the sugar in the bottling bucket thoroughly. This will result in inconsistent carbonation - some bottles under carbed, some over carbed, and some just right. The third common problem is insufficient yeast left to do the job. But, unless the beer was subject to harsh conditions after an otherwise healthy primary fermentation, this is not likely to be a problem. An infection of wild yeast and/or other buglets will often cause over carbonation issues.
System could need balancing, but if it's a consistent problem after that he just needs to be patient or check style guidelines more thoroughly
For a given beer temperature and CO2 pressure (PSIs), the eventual carbonation level (using 'set and forget') method is easily computed. (There are plenty of tables out there on the interwebs.) Know any two of the there variables, and you can solve for the third. Krusty mentioned balancing, which is what is done (with appropriate diameter and length of liquid line for the given PSIs) to ensure that beer exiting the faucet is at the right velocity for a good pour.
Then he's impatient. Set to serving pressure (10-12psi) for ten days to two weeks and the carbonation will be perfect. It's just that easy!
Under carbonated will fix itself with sufficient time at the correct pressure. Over carbonated will require releasing pressure periodically until it's right.
