Infusion Step Mash?

[storunner13]

I'm brewing my first LoDO beer on Sunday and I have some questions about SMB and infusion step mashing. I'm planning a Hochkurz schedule with a 30 minute rest at 62C, 60 minute rest at 72C, and 10 minute rest at 76C. I'm planning to recirculate the mash with a mash cap and Loc-Line, and then at 30 minutes slowly adding boiling water to the top of the mash. The boiling water will be gravity transferred through a silicone hose, the end of which is drilled with holes and coiled underneath the mash liquor.

Right now I'm estimating the infusion additions by assuming that the water will be ~96C after flowing through the silicone tubing. What SMB dose should be calculated for dough in (16 quarts)? After the first infusion to raise the temp to 72C there will be ~23.5 quarts of liquid in the mash, and ~30.3 quarts after raising to mashout.

I'm guessing I should add either the entire mash dose for ~30.3 quarts with the strike water (2867mg SMB) or add the entire mash dose for the first two step temps plus additional at sparge dosage levels for the final infusion to mashout (2388mg SMB). I'll then cool the remainder of the water to sparge temps and add SMB for the remaining water.

Another alternative is to lower the temp of the final infusion to ~90C and eliminate the sparge. Will SMB be effective at 90C? Or do I need a lower temperature to be sure it is not driven off by the high temps?

[storunner13]

Well, I'm stepping up to 72C. I was a little low on the first step (59C), so I had to added more boiling water to raise to 62C. All together I rested for 40 minutes. pH was a little higher than expected at 5.5, but not outside the window.

I tasted the pH sample of wort and was wowed by the flavor it had--very sweet, almost cloyingly. I honestly got a chill down my spine. I used 2388mg SMB, hopefully it was sufficient to scavenge the O2. I need to get an O2 meter so I can know how I'm doing... The easy part is done, I just need to be sure to transfer to spunden on time.

Mash cap is working well--though it's just plastic wrap right now. I have some 304 stainless foil delivering next week to finish the mash cap.

[ajk]

I add just enough SMB (50 g/ml in my case) for each infusion, and I don't worry about it being driven off for the near-boiling infusions. I add it immediately before the infusion and hope any boil-off is minimal.

[storunner13]

Good to know, ajk. I may try that next time.

So my efficiency was low--due to huge doughballs in the mash that I discovered when emptying the tun. I've only had problems with doughballs when conditioning the malt--milled dry I have no issues. I did brake up the mash a little as the water rose above the grainbed while underletting, but apparently it was not enough.

Should I stir a little more? Or should I be doing something else to avoid doughballs?

[ajk]

I haven't had that issue. Are you using too much water to condition?

[Big Monk]

Maybe your crush is too fine?

[storunner13]

[ajk]

Fwiw, I condition with 0.02 ml per g of grain, and my mill gap is 0.035. Others on this forum use more water and smaller gaps, though.

I would add lactic acid to get down to 5.0-5.1.

[storunner13]

31 days later, we're at 80% attenuation and the flavor is starting to come around. Still on spund, and still slowly fermenting. It's clearing a little, and the sulfur is dissipating. I have high hopes for this one.