Comment by teslabox

According to the article:

  “There are other rosins made from paper mills, where they grind pulp and extract 
  it with sulphuric acid. That rosin, you don’t want to use for potatoes,” 
  explains Baker [...]

Diamond G Forest Products is an artisanal turpentine / rosin producer (also mentioned in the article): https://diamondgforestproducts.com/