.... including but not limited to:
Understatement of the year :lol:
Attenuation, particularly from the perspective of grain brewing, is one of those things that on the surface looks like a fairly easy concept to grasp, but when you get down into it, its probably one of the most complex things in brewing.
Most of the yeast manufacturers give a "range" for each strain; but even that is based on 'averages' gathered from customer feedback, as much as anything. They can work out the specific attenuation; but that would only be relevant if all the variables were the same. From a AG perspective, you could get anywhere in the range, if you are brewing an 'average' mash in the style for which the yeast was intended (but not limited to being within the range - because of the amount of variables). From a kit and kilo perspective, because of the higher percentage of simple fermentables, you would generally consider that your attenuation would fall somewhere within the range given, and most likely towards the higher end, and possibly over. (but again, it depends on too many factors to be specific).
The only way to be more specific is to do what is called a fast ferment test, where a sample of your wort is massively overpitched, kept at a hot temperature (about 26C), and continuously agitated or aerated. This forces the yeast to attenuate fully, giving you the
limit of attenuation which is the absolute maximum attenuation the yeast will give for that particular wort. The actual attenuation you will achieve is below this by between 2-10%....but even then, the difference is limited to the strain.
Note that I've only touched on the surface, here.....I suggest you look at palmer, as suggested, and google further info on 'yeast attenuation' and 'limit of attenuation'. Go to as many manufturers websites as you can, and read all the info they have on offer, as well.
