You'll be sorry you asked, Warran, but I'll take that post as a stopper-remover.
Floating the mash has rocked my brewing world and it is making great inroads into the English style brewers in the IBUs at the moment.
Most of us AGers here in Aus learnt to brew from the US guys that started before us and they learnt from the mostly German brewers of the USA. If not German themselves, the early US commercial brewers learnt from German brew masters. Their style is to crush the grain to a powder in order to "access all the starch" during the mash, but this leads to a sticky gluggy mash with the starch at the bottom and the husks at the top. Hence the rakes in German and many US mash tuns. Keeps the enzymes moving so that they can contact as much of the starch as possible and stop the bed from setting, which makes lautering a PITA.
With a mash like that, what you end up having to do, to make the grain bed turn into a filter is recirculate the starchy, enzymy mash thru the husks until they stop the cloudiness and protein from finding its way into the kettle. Even after a recirculation, you still get some of the starch and protein into the kettle, giving hazes and whatnot.
With a floating mash, as I said in the What are you brewing II thread, you don't crush the husk, you don't break the husk-testa interface and you leave the airy protein matrix largely intact, which gives the benefit of allowing even hydration of the grain. This leaves the enzymes where they are: in contact with the starches and gets them all wet and ready for work, like they would be in a germinating seed. Conversion is awesome. As there is no powdered starch, the protein is contained in its matrix in the endosperm, runoff is immediately bright. My last batch needed less than a litre to be recirculated, more like a pint, and that was just to get a few arcospires back onto the grain bed.
Thems your benefits: clean bright runoff, bugger all recirculation and excellent conversion. Downside is that you need to fly sparge and do so slowly to leave the mash floating and to allow the sparge water to penetrate the grain to extract the sugars.
As I alluded to above, some grains are better for this than others. MO is made for the floating mash, because that's the way English brewers mash. Or maybe English brewers float their mash because that's the way their grain is malted, I don't know. I have made mixed results with Aussie malts. Some batches float well, other's not so well.
I could go on about hop additions, the German (and American) style of Bittering (full boil) + Flavour (part boil) + Aroma (short boil or flameout) vs the English whirlpool or hopback methods, but that's a whole nuther can of worms.
There is a bit of interest about this method and scarce information about it on the web, so I'll start a thread on it later on and get some input from /// who showed me the magic floaty mash.
