Originally Posted by Kaiser
Some time ago I wrote this
article to answer exactly your question. Let me know if it helped or not. I may have to add some more info.
One thing to take away is the forced ferment test. This is not widely practiced in american home breweing but It can give you very valuable information about the FG that you can expect and if you don't hit it it tells you to look for the problem in the wort (mash or extract) or in the fermentation.
The attenuations given for the yeasts, and on which most FG predictions are based on, are only a very rough guideline and don't take mashing into account.
Kai - I read your article when you first posted it. I think its a good discussion of attenuation and I found it informative.
From the perspective of a homebrewer who has had some trouble with attenuation, I thought it would benefit from including a discussion of factors that a homebrewer can control that directly impact attenuation. For example, mash temp, fermentation temp, pitching rate, yeast choice, yeast nutrients, aeration, etc.
It would be great if each of these could be discussed separately and ranked in terms of their affect on attenuation. I'm not sure if the data exists to make a rigorous comparison, but that's OK. It would still give a homebrewer a checklist to work through when trouble shooting an attenuation problem.
I guess what I'm thinking of is something along the lines of a more general discussion of factors that ensure a good fermentation, like in Palmers book (here
). That may be taking an article on attenuation too far afield.
Anyway, thanks for the article. It did help.