Partial mash isn't getting sweet

Hey guys,
I am following Deathbrewer's Partial stove top mash.
I have 2 KG of Munich in a grain bag, I have got the heat up to 160 dF twice. The first time I took the pot off the stove and wrapped it in layers to insulate. The second time I left it on the stove and checked that the temp was still around 150.
This is only my 2nd partial mash. The first one I did was with Pilsner Malt. I left the pot on the stove over night and the next morning it was as sweet as honey.
My Munich mash is only slightly sweet. It may have a little bit of the creamed corn DMS taste to it.
any ideas?

For starters, 160 is pretty high for a mash. Its possible that in heating it that high, you've denatured a decent amount of the enzymes, which would prevent them from generating sugars. Secondly, how much water are you using, and how long did the mash go for? I'll admit that I don't normally taste my mashes, so I'm not sure how sweet they should taste. However, I could imagine that some of the bready flavors you get from Munich being roasted a little more than Pilsner might wind up covering up some of the sweetness of the sugars that have been released.

I would do an iodine test.

I wrap my BK/MT in my thinsulate lined winter hunting coat after stiring in the grains at150F. Breaking up dough balls,ect to get'em evenly wet. The mash is usually up to about 152F at this point. I cover it & wrap it up for an hour. The temp usually goes up 1 degree over the hour with 5lbs of grains & 2 gallons of water. What amounts,etc did you use?

I used 2 KG (about 5 #) of Munich in 2 Gallons of water. I used the wrap up approach the first time with this batch. Then I heated it up and monitored it on the stove top to see it held around 150 for more than an hour. I think the suggestion posted here about bread flavours covering up the sweetness may be right. It was sweet but not like the pilsner batch I'd had before. Different grain I guess.
I boiled it for 90 mins so DMS would not be an issue.

Heating it to 160 for too long could well have nutralized some enzymes as was suggested. Preventing them from converting all starches to sugars. The winter hunting coat I mentioned has a lightmairy material surrounding the thinsulate that traps air. Air is a great insulator when trapped,so it holds the heat well in my BK/MT over the one hour mash. I think whatever you layered it with was insufficient to hold enough heat ofer time.

I think I did overheat it and deactivate the enzymes.
I'm hoping that the 5.3 KG of extract in my Belgian Dark Strong will make up for what I lost in the Munich partial mash
thanks
SHAL