BIAB mash temp?

Is there a good or reliable way of taking the mash temp when doing BIAB? i use both a digital thermometer and a cheap mercury brew thermometer. Howver, most of the time, i feel like its only measuring the temp of the water and not actually getting the temp inthe grain bed?!

I'm not really too stressed about it because I know i'm getting conversion and i even hit my OG spot on today. its just information i would like to have so i can kind of predict how it may turn out and so when i do my log sheet, i can factor and adjust things next time i do the recipe.

I just stick the probe of my ditial thermometer into the middle of the mash. I think because of the high water to grain ratio that the temperature of the water will be a pretty good indication of the grain, especially as the probe will be surrounded by wort and grain.
I think the most important thing is that you plave the thermometer in the same place for each brew, then at least your measurements will be consistent.

the water and the grains will most likely be the sameTEMP. , once you have stirred the grains. Also, remember that over a 60m minute mash the heat will stratify (heat rises) before you decide its time to fire tHe kettle and add heat, be sure to stir the mash vertically to redistribute the warmer and cooler mash levels.

I use a long metal candy thermometer that has a nice little clip for attaching to the edges of metal pots and just insert the probe into the middle of the grain bag.

I got this for Christmas last year. I then bought the 39" PTFE/FEP Tip Probe and insert it into the grain bed. I can then put the thermometer on top of the pot and check it during the mash easily.

Wow...Thanks for the quick responses! Definitely some good points. as diluted as the mash is, i'll bet your all right about the temps basically being the same. And since my beer has been coming out great, I guess i'll keep on like i have been.....why fix what isn't broken?! i may still try a couple of these ideas just for confirmation though.