It's worse than that. That tang in their red virginia crumble cakes is sodium diacetate. It's a food additive that gives slaty-sour flavor and also a preservative. It was ubiquitous in the tobacco industry and Sutliiff used it liberally. Ever notice that metallic sour note in their aromatics cavendishes?Unfortunately NONE… don’t let them fool you into thinking that Sutliff stuff is close, because they just spray vinegar on it.
@Sigmund Pebble Cut and Beacon were my go to’s for years. As well as the whole Blackneys’s process line.