Will my beer change in the keg?

I understand how leaving my beer in the fermentation tank will improve the beer and so on. But once I have moved the beer to the keg, cooled it to serving temperature, and started carbonating it, does it change? Is there residual yeast that might continue to process things or maybe something else?

 

Yes, depending how much time your beer spent in primary, it will be more or less dramatic. I typically transfer to a keg after 7-10 days in primary. After 2 weeks in the keg, it is nearly always visibly more clear, cleaner, crisper, basically more of whatever it was supposed to be. For ales, this continues for perhaps one more week and then seems to plateau. Lagers can keep going for a few more weeks, though. Stronger beers and Belgians will usually evolve even more over a period of months.

 

I think temp in the keg will be a significant factor. Too cold/cool and the remaining yeast won’t do much

 

Right, it's not so much about yeast in the keg as it is about settling and clarifying. Your yeast should do its thing in primary, then get discarded.

 

All my RIS/quads get better w/age in the keg. About 4months starts hitting a sweet spot. Less time with smaller beers. Whatever chemistry happens continue on. I cold crash to clean up the beer first to try to limit yeast introduction to keg.

 

Yeast don't continue to do much (except with lagers, which can continue slowly fermenting at around freezing temperatures), but chemical reactions are still slowly happening (including oxidation), some things are precipitating and solids are dropping out. As McKnuckle said, a couple of weeks in the keg will generally give a cleaner and crisper beer. Some people prefer the thicker, more intense flavours of very young beer though (particularly hop-heads) so try for yourself at different stages to see what you like.

 

I tend to see the most dramatic change after 1 week in the keg unless it's a lager, then it takes a bit longer.
IPAs are different since they are best consumed fresh. 3-4 days in keg and you want to start pounding them or else have friends over to kick it quickly...

 

Kind of like making good chili ... it seems better the next day. Flavors take some time to develop. It's not just about the yeast. Flavors will develop over time. Either fade as for hops, or develop for the better. Itll be slow, but it will change.

 

Another example: I have a porter on tap that was kegged about 12 days ago. First pints after it was carbonated were kinda meh; wasn't getting much of the nice roasty flavor it had when it went in the fermenter. Now it's settled out into something much better, smoother, with a great flavor that wasn't there before. Another week or two (if it lasts that long) and it will be practically perfect. Of course, it does depend on the style of beer, but for the most part beers get better with a bit of aging on them.