Adding Diastatic Malt to Fermenter (Potato Beer Experiment)

I've been itching to do a little brewing experiment and finally got the time over the Thanksgiving weekend. I wanted to push the limits of 6-row's diastatic power in a mash with mostly potatoes. One source I found put potatoes at 20% starch by weight with a gelantization tempurature of about 142F. I shredded 10lb of russets, added to 3.75gal of 210F water and let the (assumed gelatinized) mixture cool to my strike temp (154F). I then mixed with 3lb of crushed 6-row and mashed at 148F for 2 hours before stepping up twice with a decoction to 170F.

After boiling, my OG was about 1.046. The second day after I pitched, the krausen was up and it was working, but by the next it looked complete. I didn't test for the completion of the mash, but I'm pretty sure it's got a lot of starched unconverted. I'm using beano to convert the unfermentable sugars, and I'd now also like to add something with diastatic power to convert the starches. This is only a 2-3 gal experiment, so I'm open to risking some sourness.

Q: I'm wondering if anyone has added crushed/pulverized dry grain to primary to so any conversion? Or perhaps I might be safer with something like the following:

1) Quickly rinse some UNCRUSHED 6-row with boiling water (to kill any bacteria/wild yeast).
2) Drian, partially dry, and crush/grind grain (might introduce some bugs here).
3) Either add directly to fermenter OR mix with some 150F water and let cool to 70-80F before adding mixture to fermenter.

Any suggestions for this crazy experimenter?

I predict a lactobacillus infection with options #1 and #2, and a simple addition of fermentables with no diastatic power with option #3.

If you manage to sanitize the grain using heat I think you will denature all of the enzymes that you are trying to get at. The enzymes that convert starch to sugar only work at a reasonable rate in a certain temperature range, so even if you successfully introduced them to the fermenter I'm not sure how quickly they will do their work. It might be so slow as to not be detectable.

I am seriously confused here.

If you want to convert more starch to sugar, you not only need the enzymes, but also the proper temp, right? meaning, you will need to heat your already fermented "beer" up to the 140's to activate the enzymes...

... right?

"Slow" would be okay with me, if we're talking several days to a couple weeks for the enzimes to work at that low temp range (70F). Lactobacillus would probably eat some sugars too, but perhaps not dominate? Maybe just sour a bit? Thanks for all your input.

Just in case anyone else is remotely curious about this:

11/26 PM Pitched 1 mason jar of German Ale yeast from washed reused yeast. 11/27 Krausen. 11/28 Krausen fell. 11/30 AM Added 2 crushed tablets of beano. 11/30 PM Krausen up. 12/1 PM Added 1/2 cup powdered 6-row (with coffee/spice grinder). 12/1 AM Krausen much higher (about 2-inches; looked less "glossy" on bubble surfaces). 12/4 AM Krausen even higher and still bubbling (aroma from airlock smells fruity/slight banana).

Malt has no diastatic power outside of mashing temperatures. You definitely innoculated your beer with lacto, but the beano might be able to convert the unmashed malt, giving the yeast an opportunity to outcompete the lacto. Keep us posted.

Interesting update to this experiment:

1) After a few days with no airlock action, I lagered in a basement closet (that's a Wisconsin winter for ya) at around 48-50 for two weeks before bottling.
2) No descernable sour flavor or aroma - so at least for now - I don't think any lacto was able to propogate.
3) The final gravity was 1.003 - my driest beer yet - so the beano did it's job.
4) After all that, I'm not sure how drinkable this beer is going to be, since there's a strong "oxidized potato/potato skin" flavor that's a bit astringent. I recall seeing the potato shreds blacken a bit when exposed to oxygen when the sparge water level dropped below the mash bed top. The color of the beer even has a yellow-ish/black-ish tint to it.

I plan to bottle condition it for a long time in my basement (50-55F) and see if it becomes drinkable. Overall, pretty fun experiement with enzymes in fermenter and seeing the laco that was most likely in the raw malt not be able to do anything by the time it was added.

Would the alcohol in the already fermented beer immediately denature the enzymes? It's a possibility, right?