Wood finish to handle high temperatures (not turn cloudy)
I would not use a urethane finish as it will quickly turn with high heat, since it is a food processing area I would use linseed / flaxseed oil. It will preserve the wood and can handle some moisture. At my last house I had a large oak butcher block that I used linseed oil on it took a large amount of abuse as that's where I prepared meats for summer sausage and for large brew pots, when the surface got a bit chewed up I used a metal scraper purchased from a local butcher shop that shaved a tiny amount of the surface then recoated, I did try a blend of bees wax and oil 1 time but this created marks with large pots. The best advice I have is to use food grade oil and wipe up excess water don't let it sit the wort is a great food for "stuff" to grow in so a through wipe down after use is a good idea.