I have used Mr Malty for most of my starter calculations over the last few years and also have noticed the slurry tab as well. It has always done me right
Kai - I mostly do lagers as well and saw the billions per gram calculation in your blog post. I must admit that I do a lot more lagers than ales at this point so that information is top notch. With that in mind to pitch around 500 billion cells I am looking at a thick slurry of around 111-112 grams. Does that sound about right?
Also, what are the differences in weight with ale yeast? More cells? Less cells? If I were going along with the 4.5 billion per gram assumption it would put me at pitching 55-56g for 250 billion cells. Is that a safe assumption?