Overcarbed or Cold crashed keg?

[jvhoef]

I am only on my third batch of home brew so I am still on kits. My first two kegged and drank well but had just been done as 3 weeks in the primary and then into the keg. For this batch I made the lemon coriander from Midwest so it was the first time using a secondary. After 2 weeks in the primary and 4 weeks in the secondary I transferred to the keg at room temperature 65F and bumped the pressure to 30 psi for about 30 hours. I then dropped it to 12 psi and let it sit for a week. On tasting it was excellent and greatly loved by the wife. Due to lack of space in the mini fridge it just stayed at room temp for the week but was still consumed and quite good. After transferring to the fridge 44F, the flavor dramatically changed and it lost a lot of the creamier(mildly) stronger flavors. It also seems to be smaller bubbles but about the same amount of head when pouring. I am presuming that is due to the yeast settling out to the bottom rather then being mixed more throughout?

My question is, can you chill the beer without everything crashing to the bottom and how much difference would there be in the carbonation level?

 

[Soviet]

When you "cold crash" you want the yeast and some other protein compounds to settle to the bottom. This should not affect flavor in a negative way. Quite the opposite, it should improve the flavor.

That said, your experience was affected by a few different things. First, serving temperature. Undoubtedly your palette perceived a richer mouth-feel, more volatile aromatics and flavors at a higher serving temperature. While cold crashing works best at freezing temperatures (remember water freezing temperature is higher than that of beer with alcohol in it), it's certainly not the right temperature to serve beer at. I serve my beer at 40-45 F, and that works well for me.

Second, dissolved carbonation. Carbonation definitely contributes flavor to beer. Consider it a part of your recipe—different styles call for different "volumes" of dissolved CO2 in your beer. A Belgian Dubbel, for instance, would be much more highly carbonated than an English Bitter from the cask.

Third, consider the fact that when you lowered the temperature of your keg, your beer immediately absorbed more CO2 (became more carbonated) even if you kept the pressure constant. This is because CO2 is more soluble in beers of lower temperatures. Another words, as temperature goes down, the PSI must come down to maintain the same level of dissolved carbonation. use this handy calculator to figure out what you're looking for: http://www.brewersfriend.com/keg-carbonation-calculator/

And here's a general look the carbonation guidelines for different styles of beer.

One final consideration. The first couple of days you are pumping CO2 into the beer under high pressure, it tastes much different than it would after about a week when it "stabilizes." Even when your beer seems carbonated those first few days, the CO2 has not fully "blended" into the character of the beer. Anyone who doubts this should taste their force-carbed beer the night after leaving it on 40 PSI or so. Take notes on what you taste. Then turn the psi down and let is sit at the target pressure for about a week or two. Taste again, take notes.

 

[jvhoef]

Thanks for the input, that is about what I was thinking. I will have to work on getting the flavor/carb right. Maybe it it one that I will be serving "warm". Is there any advice on the C02 coming back out of solution when it warms but I keep the pressure constant?

 

[Soviet]

If you warm up the keg but keep the pressure constant, you will get very foamy pours because you have already "over-carbonated the beer." Over time, your beer will become less carbonated at a warmer temperature and constant pressure, but in my experience, it takes far longer (several weeks) to "decarbonate" to the level you're looking for that to dial it in when carbonating completely flat beer.

I would suggest that you turn the pressure down to about 3-5 PSI, just enough to let the beer flow slowly out of the keg, and it should decarbonate faster.