Q: 60/40 wheat mash - after 2 hours iodine test not good, what to do?

[mr_wibble]

Hi-yas,

I've had a mash going since 07:30 this morning (bloody chooks going crazy at 05:ugh).

The pH is 5.1 (by papers), the Temp is 62 (started at 66 in esky mash tun), the wort S.G. is 1.065.
Half hour before the S.G. was 1.060.

But the iodine test is still going a little bit black - not inky black, but as I swirl the 2 drops of iodine (tincture) around in the 1 teaspoon of wort, it slowly tends a little bit towards blacky-purple.

With the temperature dropping, am I going to do any good letting it sit longer?

What do I do now?
- Wait?
- Raise the mash temperature with more water?
- Other?

thanks,
-kt

EDIT: The probe thermometer just poo'ed itself on the very next reading, so we can take that 62C temperature with a grain of salt. Previously the esky-tun has held temperature for hours.

 

[pk.sax]

You could have some less crushed grains in there slowly releasing more starch. Give it a mighty stir and thrashing. Then mash out with higher temp sparge water. The leftover starches *should* convert otw to the kettle.

As long as you have target gravity all is good.

 

[mr_wibble]

Ok, it's been nearly 3 hours now.

Guess I'll just take what comes.

 

[grimpanda]

I'm assuming you're using malted, and not unmalted/raw wheat?

I've experienced this too on the odd occasion - just the faintest amount of purpley-black inkyness when testing with iodine that fades away to a dark red. I usually just use one drop of iodine on a sample of wort (less than 5mls) on a white plate/saucer. With these beers I've never had issues with starch haze. I always do a mash-out to about 74c for 10 mins before draining & boiling.

You could try a protein rest next time and see if that improves things, but as practicalfool said, if you've hit target gravity then RDWHAHB.

 

[mr_wibble]

Yeah I think practicalfool nailed it.

I checked the gravity into the kettle - it was spot on.

Digging through the spent mash, there was quite a few mostly whole grains in the mash. If these can give slow starch leakage, then that would be the culprit.
I should ask to have my wheat malt double-milled. (Or save up for my own mill).

Made for a very long brew day.

cheers,
-kt


EDIT: yeah, it was malted wheat + barley

 

[Bribie G]

Wheat malt is the easiest to mill as it's huskless so I don't know why there should be whole grains in there, sounds like your supplier was a bit lax there, maybe some whole grains escaped from a hopper and ended up in the collecting bucket.