Mash time / sac rest

I mash, normally for an hour @ 150-F,
batch sparge & let the 2nd runnings sit for 30 minutes.

That being said, my question is have any of you for whatever reason decided to say, mash overnight for your 1rst runnings to vourloft 1rst thing in the morning?
If so,details of how it turned out?
Did it have that `grain left wet too long smell to it?
(like if you forgot to clean the grains out that day for w/e reason to remember it 2-3 days later)

I'm all ears.

I have never tried that. In fact I have never let my 2nd runnings sit except through getting ready for the next step. I have read of long mash times and also people that are shortening the mash to about 20 minutes.

??? If it works ??? I might push the envelope a little. But overnight is something I will let you try first......

I don't let the 2nd runnings sit any longer than the time it takes to stir pretty thoroughly.

I'm trying to make the move to a shorter mash time. 45 minutes or so.

Here's a bit of advice I was given about the implications of longer mashing so I thought I'd stick it here, seems like sound info!

Particularly: 'The potential disadvantage of mashing too long, is that it gives more time for the amylase enzymes to chop up poly-saccharides into mono and di-saccharides. Poly-saccharides are not fermentable, and contribute to the maltiness and mouthfeel of finished beers. Mono and di-saccharides are fermentable, so contribute alcohol to the beer, but little in the way of mouthfeel. If you are looking for a drier beer with thinner mouthfeel, then longer mashing won't hurt. But, if you want more maltiness and fuller mouthfeel, then excess mash time can be detrimental. The types of malt in the grist also interact with the potential amount of mono and di-saccharides, so like most things in brewing: "it's complicated."'

Overnight mashing sure is complicated because you have the grains in contact with the water for a much longer period of time which would suggest that you would get a very fermentable wort with the beta amylase working for such a long period but beta amylase is denatured at mash temperature so it may not give you a much more fermentable wort after all. People have done it and report good beer is the result. Give it a try! There is so much going on in the mash that predicting the outcome is very difficult.