At the risk of causing 'Have you REALLY tried to search the forum' cries, can I post my worry here?
I was making ciders for many years and the concept of remaining sugars was simple: unless you sulfited or by sheer luck the yeasts would gobble up all sugars in the fermenter and you ended up with perfectly dry cider. With beer recipes I see different final gravities from a not so diverse range of malts in the wort. If the recipe says FG 1.015 - what explains that the yeast will stop at that point and refrain from mopping up the rest of the sugars? Is this a known quantity of unfermentables in the combination of malts? A yeast that will give up precisely at that point? How do I know that it's not going to drop massively in the bottle?
This is not theoretical: I have 20l of weizen racked into the carboy 10 days ago. It's at about 1.010 right now, but it still burps from time to time. The recipe indicated 1.012 as FG. If I bottle now, adding some priming to bottles and the beer still fermenting - am I going to end with a fire extinguisher instead of a drink? Is there such thing as a 'safe' FG for bottling IF your airlock still gives an occasional bubble?
I was making ciders for many years and the concept of remaining sugars was simple: unless you sulfited or by sheer luck the yeasts would gobble up all sugars in the fermenter and you ended up with perfectly dry cider. With beer recipes I see different final gravities from a not so diverse range of malts in the wort. If the recipe says FG 1.015 - what explains that the yeast will stop at that point and refrain from mopping up the rest of the sugars? Is this a known quantity of unfermentables in the combination of malts? A yeast that will give up precisely at that point? How do I know that it's not going to drop massively in the bottle?
This is not theoretical: I have 20l of weizen racked into the carboy 10 days ago. It's at about 1.010 right now, but it still burps from time to time. The recipe indicated 1.012 as FG. If I bottle now, adding some priming to bottles and the beer still fermenting - am I going to end with a fire extinguisher instead of a drink? Is there such thing as a 'safe' FG for bottling IF your airlock still gives an occasional bubble?