The Mash That Didn't

[frazier]

OK so, Ive been brewing for four years, have dozens of all-grain batches under my belt, and I've never had a mash that didn't convert. Until tonight.

The grainbill was simple: 10 lbs Marris Otter; half pound Victory, half pound wheat. Dough in at 165, stirred a bunch, temp stabilized at 152. After 45 minutes, I came back to heat my sparge water, and did the iodine check. It was solid black. I mean, Solid. Black. WTF??

A half hour later, still black. After 2.5 hours mashing, the iodine showed brown and black mixed. It's too late to brew now, the whole schedule is impossibly messed up. I'm going to let it sit overnight, but my gut feeling is that I'll be dumping the batch and getting new grain.

The grain was purchased at my LHBS on Saturday, ground there, brought home to brew.

Anyone ever seen anything like this? I am at a loss.

 

[JoeHoffman]

Wow that's weird, what's your water supply, city, well, bottled. My water supply changes seasonally and I constantly have to adjust my ph accordingly.


Pleas excuse my dyslexia

 

[dryboroughbrewing]

I'd probably check my thermometer (and maybe get a new tincture of iodine just in case), this seems like it has to be a measurement issue.

 

[BBL_Brewer]

I'm wondering if it did convert, and the iodine test just didn't turn out right for some reason. If it didn't convert in 1.5 hrs, it probably wasn't going to. At the risk of wasting hops and energy, I probably would have gone ahead and boiled and saw it through. Leaving it sit over night is going to ruin it for sure. Unless you want to go on the fly and crank out something sour. Let us know how the next batch turns out. This is something you don't hear very often.

 

[bleme]

I saw a guy on here in the last week that regularly mashes in at night and sparges first thing in the morning so that part should be OK. No idea why it wouldn't convert unless the LHBS got their bags mixed up and it wasn't really MO.

 

[BBL_Brewer]

I saw a guy on here in the last week that regularly mashes in at night and sparges first thing in the morning so that part should be OK. No idea why it wouldn't convert unless the LHBS got their bags mixed up and it wasn't really MO.

Yeah, but you have to keep the temps up. Drop too low for too long and things start getting funky.

 

[frazier]

Wow that's weird, what's your water supply, city, well, bottled. My water supply changes seasonally and I constantly have to adjust my ph accordingly.

This is the solution, it seems. I brew with RO water, and make appropriate adjustments. I discovered my bowl of mineral additions sitting off to the side - when I stirred them in to the 3-hour old mash, everything converted within 15 minutes.

Thanks all,

 

[Hello]

Dumb question but can you not actually brew with straight RO water & no additions?

 

[thaymond]

Dumb question but can you not actually brew with straight RO water & no additions?

I do. Works fine for me, and I get tasty beer, but I'm sure with additions it may be better.

 

[JoeHoffman]

Dumb question but can you not actually brew with straight RO water & no additions?

If the grains you are using have enough minerals and buffering capacity to move the ph to the proper place then yes but this is very unlikely especially with light simple grain bills like the one in question


Pleas excuse my dyslexia

 

[frazier]

OK, so time for a follow-up: OG 1.054, yeast S-05; FG 1.006. So, a lot of simple sugars came out of that extended mash. But, it will be beer!

Tasted awesome at bottling btw.

Cheers!