Brewers pitch has been used for hundreds of years to make beer barrels and drinking cups waterproof. It is still traditionally made from tree resin in a few places. This brewers pitch is transparent, the wood grain remains clearly visible. When the brewer pitch is in the package, it is hard. To use it, it must be heated.
Heat the pitch in a pan (preferably electric) to 180 to 200 ℃. Pour the liquid pitch in the form you want to make waterproof. Drain the liquid pitch back into the pan as you rotate the workpiece. This way you can be sure that the pitch has hit all of the wood well. Allow the mold to drain and dry. Your work is food-safe waterproof. The pitch that goes back into your pan can be used again.
Make sure you let a large amount of the pitch run into and out of your workpiece. This ensures that the pitch dries evenly, which benefits the result.