Very interesting!

From a recent BYO wizard segment:

.....In fact many pub brewers mash-in, take a short breather and begin wort collection. My old professor from University of California-Davis is the one who started pushing this idea. The reason it works is that there is no mash-off step and as long as the wort collected in the kettle is not prematurely heated, conversion of starchy worts continues in the kettle during wort collection and the amylases in the mash are active during almost the entirety of sparging. Brewers doing this use much shorter mash times.

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http://***********/mrwizard/1593.html

I might start doing this. It makes me want to smack my head and say "Why didn't I ever think of that???!!!??"

But what about the starches left behind in the grain? Your efficiency would end up low wouldn't it?

We'll know the answer once dude tries it. It makes sense. I often take a while getting the sparge water hot enough and my 60 minute mash ends up being 75, then the 10 minute mash out is always longer. I think I'll skip the mash out on my next AG and rely on the 'activity' during the sparge.

I wonder if the software (I use beersmith) accounts for the activity in sparge time. I doubt it but ??

I think it is worth experimenting with. I'd prolly do a 20 minute mash and then this. We'll see the next time I do regular infusion mash.

I'd love to start cutting off some time of a brew day now that summer (and 95°, 100% humidity) is around the corner. This would shave about an hour off of a 6 hour brew session. I like that.

Worth a shot. Go for it and let us know what you come up with. With modern malts converting in often 30 min, it's definately worth looking at.

combine this with a batch sparge, and bleach for sanitizer and we'll be brewing all grain in two hours!

seriously, sounds like a worthy experiment for the next bitter coming up.

Maybe I'll try it for the Bent Rod Rye. The 3CPA looks like it will be done in another 24 hours, so I can use the cake again.

it should work, all of the starches should go into solution with in ...ohh...maybe 15 mins (?) whatever it is...once the starches and the amylases are all in solution, youre good to go.
I have never done a multistep mash, but isn"t one of the first step at a low temp to dissolve the starches?

I have done a similar thing. If my conversion test looks close but not fully complete, I'll just lauter because I know that by the time I get it all drained and sparged it will be finished. You can get an idea of how fast conversion is taking place simply by looking at a few intervals in time with the Iodine. I am not sure what the larger scale lauter times are generally?

I'd suppose this could approach typical efficiency if you stirred the mash vigorously during those 20 minutes, as well as during the sparge(s), so as to dissolve more of the starches.

I think your grain crush might be very important here. Starch DOES NOT dissolve in water. When it is attacked by the amylases, the released sugars do dissolve into the water. If you have a very course crush, and you drain off your wort prematurely you'll be leaving a lot of the starch behind. If you have a fine crush, then the starch could be in suspension as you drain and would continue to be converted into sugars that then dissolve. Your starch pieces need to be small enough to stay in suspension while you drain - like that milky picture someone recently posted that I can't find. As long as the enzymes are still active, it will convert.

Take a Tbsp of flour and mix it with say 100 ml (3.5 oz) water, then let it set for a while to settle out (actually you might not need to wait). Put a hydrometer in the solution and the SG will be close to 1.000. The starch does not dissolve and therefore does not contribute to SG of the solution.

As long as your crush is good enough I think this could be a good time saver.