I've been taking the original gravity and multiplying the apparent attenuation of the yeast. For instance:
1.040 OG x 75% apparent attenuation = 1.010 expected FG
But I never seem to get there. My fermentations look really healthy. Are my expectations realistic? Is this just hard to get right?
Here's a real world example:
I made a beer using this recipe:
- 0.5 lb 40L Caramalt
- 3.3 lbs extra-light LME
1 lb extra-light DME
1 oz Fuggle @ 60 mins
1 oz Fuggle @ 1 min
0.5 Whirlfloc tab @ 10 mins
- 0.5 tsp Wyeast yeast nutrient @ 10 mins
Yeast: Wyeast 1098 British Ale
Very short lag, healthy-looking initial fermentation with a clean white foam cap that fell back into the beer after three days.
This yeast has an apparent attenuation range of 68-72%. Thus, I would expect an FG of 1.010 to 1.012.
When I put it in bottles last night, it came in at 1.016.
I appear to be doing everything recommended. For aeration, I'm pouring through a sieve, then sloshing for five minutes. Maybe that's the missing link? Or are my expectations too high?