There probably aren't any two woods that confuse more people than American chestnut lumber and the members of the white oak family. Reclaimed white oak and chestnut lumber will look nearly identical in their rough state. However there are a couple of characteristics unique to either species.

Chestnut Lumber is lighter in weight than Oak. It is also softer to plane down to a finish and ages to a gorgeous golden brown color. There are two types of chestnut available, pre blight which is rarer, and wormy chestnut. The blight killed off the chestnut at the turn of the 20th century so at the time there was quite a bit of chestnut on the market until the 1920's and maybe later. Structures built in the mid to early 1800's have pre blight chestnut without worm holes.

The best way to determine between chestnut and oak is to look at the end grain. Your old oaks will have rays running perpendicular to the rings. Rays are also known as fleck and are what give quartersawn oak such praise. However American Chestnut does not have rays or fleck.

The wormholes from blight killed chestnut will have a black or dark brown stain. Woods eaten by powder post beetles usually has dust falling from the holes and the holes are not stained dark, usually.