I’ve been brewing for a little over a year and I’ve ran into my first problem I can’t seem to figure out on my own. I brewed an all grain Oktoberfest a couple of weeks ago. Original gravity was 1.057 and brewers friend estimated final gravity at 1.012.
I pitched a 4 liter starter, decanted, of wyeast 2633 oktoberfest blend yeast and fermented at 48°. After 8 days, gravity was at 1.025, and fermentation was pretty active. I set the temp controller to let the beer free rise to 62° for a diacetyl rest. It took 24 hours to come up to temp, and fermentation just stopped. Blowoff activity stopped, and the Krausen fell. I took a sample and measured final gravity of 1.022 with my refractometer, after alcohol correction. I verified this with a calibrated hydrometer. I have never had a fermentation abruptly end like this an I’m trying to figure out what caused it.
My mash temp was 154°. I do full volume BIAB. I mashed in and temp was 156°. I always keep a little water back just or this reason. I added the rest of the cool water and brought the temp down to 152°. I fired the burner and slowly brought temp back up to 154° while stirring. I mashed for 60 minutes and only lost 1 degree during the mash. My mash efficiency was 95% this batch, which is low for me as I’m usually 99%. The boil was uneventful. I chilled with my immersion chiller to 52° within 25 minutes, pitched the starter, and put the beer in my fermentation chamber.
I usually get attenuation in the 75-80% range and my FG is typically a couple points below what the software predicts. This batch, my apparent attenuation is only 61%. Can anyone give me some insight into why I’m 10 points high this time?
I pitched a 4 liter starter, decanted, of wyeast 2633 oktoberfest blend yeast and fermented at 48°. After 8 days, gravity was at 1.025, and fermentation was pretty active. I set the temp controller to let the beer free rise to 62° for a diacetyl rest. It took 24 hours to come up to temp, and fermentation just stopped. Blowoff activity stopped, and the Krausen fell. I took a sample and measured final gravity of 1.022 with my refractometer, after alcohol correction. I verified this with a calibrated hydrometer. I have never had a fermentation abruptly end like this an I’m trying to figure out what caused it.
My mash temp was 154°. I do full volume BIAB. I mashed in and temp was 156°. I always keep a little water back just or this reason. I added the rest of the cool water and brought the temp down to 152°. I fired the burner and slowly brought temp back up to 154° while stirring. I mashed for 60 minutes and only lost 1 degree during the mash. My mash efficiency was 95% this batch, which is low for me as I’m usually 99%. The boil was uneventful. I chilled with my immersion chiller to 52° within 25 minutes, pitched the starter, and put the beer in my fermentation chamber.
I usually get attenuation in the 75-80% range and my FG is typically a couple points below what the software predicts. This batch, my apparent attenuation is only 61%. Can anyone give me some insight into why I’m 10 points high this time?
