How much unconverted starch?

[feinbera]

I'm planning the recipe and infusion schedule for the "base beer" to kick off my sour program. I'd like to avoid the traditional Belgian turbid mash – I'm still enough of a n00b that a single-infusion batch-sparge brew day kicks my butt, I'm not convinced that me, my dog, and my marriage would survive a true trubid mash.

I figure I'll do the "lazy man's trubid mash" and pull a small volume of first runnings right after I mash in, then quickly bring them to a boil to denature the amylase enzymes and leave the starches unconverted, to be added back into the boil after the rest of the grain is mashed and sparged. My question is, how much unconverted first runnings, either in terms of points or volume, do I need to pull?

I'm looking at an 11.5 gallon batch into primary (enough to fill two five-gallon carboys to the neck for bulk aging with bugs), 1.050 post-boil gravity, 60/40 2-row/flaked wheat.

 

[MarshmallowBlue]

Why not just mash high? You won't get starches, but you'll get long chain sugars that sacch can't eat.

 

[sweetcell]

there are easier ways of getting starch into your wort: add some flour, boil some oats, etc. and add that to the boil.

mashing higher may or may not work. depending on how (overly) modified your malt is, temps might not have a big effect.

 

[WhamFish]

I just do a 150F single infusion then run the wort threw a hop bag with 1 lb of quick oats as it goes to the kettle. That should get plenty of stuff for the bugs to work on and also add proteins for body.

 

[feinbera]

Flour, huh? I mean, I know it's just wheat, but that feels wrong... I'm brewing infected beer, not baking a cake!

Anybody have any ballpark numbers for amounts of flour/oats/whatever? I know sours aren't an exact science, but I feel like it's at least a little more accurate than "some"?

 

[WhamFish]

1lb oats in a 5 gal batch seems to do just fine. If you are just running the wort through them on the way to the kettle you will not get full extraction from them. So don't add them to your OG calculations, or do and just plan on coming up short of your normal efficiency