Mash Temperature and Mash out

[outterbanks]

On all-grain brewing is the temperature based on the grain bed or the wort? If the grain bed temp drops the wort temp will be much higher to get the mash temp back. Does that cause off-flavors? With a mash out at 168 is that the grain bed temp or the wort temp?

 

[Kickass]

What’s your mash setup?

After initial stirring the grains and water, the entire mass should be close in temp. Sure warm or cool spots will exist but, in my experience, never enough to noticeably have a negative impact on the over product.

What’s your mash out process?

 

[PCABrewing]

On all-grain brewing is the temperature based on the grain bed or the wort? If the grain bed temp drops the wort temp will be much higher to get the mash temp back. Does that cause off-flavors? With a mash out at 168 is that the grain bed temp or the wort temp?

What you are aiming for is the average temp throughout the mash tun to be at your desired temp.
You will never have it all exactly on temp.
So your question is a bit tricky. I presume when you say "wort temp" you mean the temp of wort exiting the tun. That can be a few degrees different than the center of mass of the mash.
I generally use a digital probe and spot check a few different places in the mash to make sure I don't have any hot or cold spots.
I also recirculate that helps even out the temp throughout.

 

[PCABrewing]

I also preheat my mash tun with warm water before I mash-in so that I don't lose a bunch of heat by heating the walls.
Beersmith allows me to specify the temp of the hardware so that helps define a schedule.
I can usually count on being within one or two degrees of my target that way.

 

[hotbeer]

I thought it was for the wort you have collected. The wort is where the enzymatic action is that you are trying to stop by doing a mash out. Though I do sparge with 170°F water.

If you are going straight to the boil with your wort, you might not need to mash out. Many don't. I've been on both sides of the issue. However lately I've been taking a longer time between mashing and finally beginning the boil process, so I've been doing a mash out.

Perhaps for the hour or two longer I'm going between completion of mashing to beginning the boil isn't an issue for any further enzymatic changes to the wort, but since I don't know I figure it's a good step to do since it's so easy.