Starch conversion to sugar

I thought this may be of interest to some.

I was showing some one the process of all grain brewing and used this to show them how quick and easy mashing is. (Converting the startch in the grain to sugar)

Iodine reacts with starch and turns black.

I took two samples of grain and added water at 68°C (155°F) and added a dash of iodine to one of the samples(Idophor will do)
The result. Black = Starch = No yeast food (Sugar)



I did the same with a second sample and placed a towel over it for 20 minutes to insulate and keep a stable temperate.
The result in just 20 minutes = reddy/brown = No starch = Sugar for the yeasties.



Most people leave the mash for 60 minute plus. But this shows in optimal conditions then 20 minutes can do the job.



If you do a taste sample (before adding the iodine) to will taste that the second (mashed) sample is sweet.

Thanks for the info Orfy. That 20 minute mash has been rattling around in my head for a couple of weeks. I tried it with the coffee pot experiment. Just wondering about a larger batch.

I was listening to a Brewstrong podcast yesterday (could have been an old show, don't know as I just subscribed) and JZ and John Palmer were talking about conversion that happen almost immediately under lab conditions. 60mins is supposed to be an "abundance of caution" length of time.

I had also read an article (in an old Brewing Techniques issue?) where the tech dudester was ranting about 60mins being wasted time. So the next time I mashed I iodine tested at 30mins but my mash wasn't completely done. I didn't check again until 60mins since I was multitasking, but by 60mins the conversion was completely done.

I think I will start checking for conversion at 30, 45, and 60.