Recently, I stumbled into BlackSwan Barrels, they produce different types of barrels and other wood aging products. They offer something I have never seen before. A honeycomb insert, almost like a spiral.
|3/4 by 3/4 for inserting into your carboy|
I got a package today of the 6 honeycomb inserts. They look really well made and have this (above) in each package.
|This is the Red Oak @ 5" long|