[tommymorris]

Sorry if this has been asked, but, what if you cold crash before carbonation?

If it's crashed for a long time, like a week or more, I might cheat it downward a little bit, but even in that case it might not be a perceptible difference. Diffusion through the surface area of the beer is going to be pretty slow. Think about a keg of flat beer - it takes weeks to carbonate using only the head space, and that's at roughly twice the pressure, with a supply to make up what's absorbed.

Not to mention most of that suck back is due to shrinkage of both the gas in the headspace and the liquid, not further absorption of co2.

Great point. I didn't think of the shrinkage factor.

http://youtu.be/09t5EOUt0ys

[69franx]

Sorry if this has been asked, but, what if you cold crash before carbonation?

If it's crashed for a long time, like a week or more, I might cheat it downward a little bit, but even in that case it might not be a perceptible difference. Diffusion through the surface area of the beer is going to be pretty slow. Think about a keg of flat beer - it takes weeks to carbonate using only the head space, and that's at roughly twice the pressure, with a supply to make up what's absorbed.

Not to mention most of that suck back is due to shrinkage of both the gas in the headspace and the liquid, not further absorption of co2.

Great point. I didn't think of the shrinkage factor.

http://youtu.be/09t5EOUt0ys

Nice!

[HoosierBrew]

I didn't think of the shrinkage factor.

The dreaded George Costanza problem. 

[flbrewer]

Was going to post the same question...after reading this thread I have a similar one.

Highest temp after fermentation is over, I get it. BUT does it matter that I'm currently keeping my beer at a certain temp? Is it the temp the beer reaches naturally on it's own?

For instance, my beer hit a high of 73 yesterday and I'm certain that I'm 95% done with fermentation. (See my gravity readings below). It's now sitting in a water bath at 71.5 and I imagine it'll float around that number for the rest of the week until bottling.

What the heck number do I input into a priming calc? 

11/15- 1.062
11/18- 1.020
11/19- 1.018
11/20- 1.016
11/21- 1.015
11/23- 1.014
11/24- 1.012 (currently at 80% apparent attenuation, 6.83% ABV)

[morticaixavier]

put 73. that's the level it has more or less reached equilibrium at.

[klickitat jim]

Ive learned the hard way to be extra certain that fermentation is complete before bottling.

[flbrewer]

put 73. that's the level it has more or less reached equilibrium at.

Thank you sir! How critical is the temp entry in these calculators? Will I have a bottle bomb or under carbed beer if it's off by much? For instance, with the above temp, I end up at 4.34 ounces of corn sugar. If I were to enter 71 degrees, it would be 4.27.

[Jimmy K]

I doubt you'd notice that shall a change. Even a full ounce difference probably won't cause bottle bombs.

[a10t2]

Thank you sir! How critical is the temp entry in these calculators? Will I have a bottle bomb or under carbed beer if it's off by much? For instance, with the above temp, I end up at 4.34 ounces of corn sugar. If I were to enter 71 degrees, it would be 4.27.

That would be about a 1% difference in the final carbonation level.

[klickitat jim]

Correct me if I'm wrong someone. But assuming the beer is totally done, the priming sugar adds around 3 gravity points. So it should be evident how important it is to be sure it's done. If it still has 3 points to go and you add 3 points, you'll end up with a mess and a waste of beer.

[tommymorris]

Correct me if I'm wrong someone. But assuming the beer is totally done, the priming sugar adds around 3 gravity points. So it should be evident how important it is to be sure it's done. If it still has 3 points to go and you add 3 points, you'll end up with a mess and a waste of beer.

You are definitely right, bottling before fermentation is complete can lead to bottle bombs. I don't think FLBrewer is going to bottle just yet. He said he thinks fermentation is 95% complete. Sounds like he is still planning to wait a bit longer.

PS. That's a lot of gravity readings, FLBrewer. You need one of this morebeer gravity beerbugs.

[klickitat jim]

Copy that. I guess it sounded to me like he was ready to go. For what its worth,  normally I take a reading before I pitch. The next one isnt until im pretty sure its done. Like no airlock activity and nothing on the surface. Then one more a few days later to be sure. Its rare that I take more than 4 total

[flbrewer]

Nope, not bottling! What's a morebeer gravity beerbug?

[flbrewer]

Jim, when you say it adds 3 points are you saying it actually subtracts 3 points? For instance, I'm at 1.012. If it were completely done, the sugar would bring it to 1.009?

[Jimmy K]

Jim, when you say it adds 3 points are you saying it actually subtracts 3 points? For instance, I'm at 1.012. If it were completely done, the sugar would bring it to 1.009?

Other Jim means when you have beer ready to bottle at 1.009, then you add priming sugar it will bring the gravity to 1.012. The yeast will then eat the priming sugar which will return the gravity to 1.009.