Low Carbed, cold crash questions

[V-Fib]

So I have my 1st two all grain brews bottled, one stout and one IPA. Both had lower than expected FG due to to much water being used. The batch size in the fermenters were 3 gal, I didn't use a yeast starter but I pitched an entire Wyeast smash pack in each carboy figuring the extra yeast would compensate for no starter. I fermented each batch for 30 days at 62 degrees (my basement temp). Then I cold crashed for 2 days at 33-36 degrees. I used NB carb calculator to figure out how much corn sugar to use and estimated the brew to be at 40 degrees to make up for warming during bottling. I boiled the corn sugar in minimal water added it to the bucket than siphoned the beer into it. I bottled in swing tops and kept the bottles in my basement at 62 degrees for 2 weeks. After reading some stuff I moved the bottles into an upstairs closet at 71 degrees for another week. I tested a bottle of each yesterday and both were under carbed.

So my questions to prevent under carb again do I let my fermenters raise to room temp to reduce the temp the chance of inaccurate sugar used?

Did I use to little yeast?

Was my yeast to old and weak by the time I bottled?

Did the low temp fermentation and first 2 weeks of bottling kill my yeast?

 

[Pie_Man]

Do you recall how much priming sugar you added?

I think the yeast remaining after fermentation and cold crashing should have been healthy enough to carbonate the beer despite the cooler ferm/carbonating temps.

 

[jdauria]

Low fermentation temps would not kill the yeast, but a 30 day fermentation and then cold crashing could drop all the yeast out of suspension leaving very little to be transferred to bottles to eat the corn sugar. You also don't want to bottle cold, after you cold crashed, you would want to let it warm up again.

You may have been Ok on the amount of yeast you pitched, since it was only 3 gallon batches. But the amount you pitch is determined by the original gravity of each beer and the age of the yeast pack. The older the yeast pack, the more yeast you need, ditto with the higher the starting gravity. Would recommend using a yeast calculator, there are many online such as YeastCalc and MrMalty.

62 was awesome pretty low temp for the bottles to carb at.

And while I am not a swing top bottle expert, I know swing tops don't seal as good as regular crown cap bottles. When the beer is carbonating in the bottle, the bottle is under pressure and if a swing top does not have good seal, that carbonation could escape some.

But welcome to All grain brewing, you will get all your procedures down before you know it!