DIY Mash Paddle

If I were to make my own wood mash paddle does it need to be treated in anyway?

Nah.. just don't use a pitchy soft wood like pine or fir. A nice stick of hardwood or even "whitewood" should work fine. I sometimes use one of the paint stir sticks from HD.. the long ones used for 5G buckets. Doesn't take much unless your mash is like porridge/thick oatmeal

This is mine I made for a piece of poplar. I have not treated it in any way.

I do some wood working and am thinking what you would use that you would be ok with putting in 150 degree water, I can't think of anything. Some of the chemicals that are in varnish, laquer, urethanes are not food safe. Something like linseed oil, mineral oil would come out in the water. The wooden spoons you use in your kitchen aren't treated. Whatever your stirring is still going to get boiled later. I say unfinished.

Agreed.. unfinished. Linseed oil has a horrible odor and taste. Mineral oil is generally considered great as a butcher block oil... but...

Anything that might grow in an unfinished paddle will be SO DEAD once it hits that hot water or finally transferred to the BK.. No Issue

I made my paddle a couple years ago out of birch. No treatment of any kind - just cut it and sanded it. I hose it off after my brewing is done and hang it over my bar until the next time. No sign of any bad things growing in it and since it is used pre-boil, I'm not to worried it will cause any issues.