Why not petroleum products?
I noticed that some natural cork tenons last a very long time while others prematurely failed and even disintegrated. Some incorrectly refer to this latter situation as “rotting.” Common practice had it that one should grease cork tenons. The prevailing greases were petroleum-based. Without grease of any kind, the cork dries out and indeed disintegrates. With petroleum grease, the cork was still failing. Since rotting is a biological process, but petroleum grease is not a biological agent, the cork was not rotting per se. I needed to find an emollient that was not petroleum-based. I observed the results of greasing corks with both petroleum-based and organic-based greases. I found that petroleum-based cork grease would cause natural cork to become increasingly hard and brittle. Often, the glue bond will fail. The cork will separate eventually from the tenon in long strips, or fracture into tiny pieces. Tallow-based cork grease, as an emollient, keeps the cork soft and pliable. It does
