El Choco is a dark pigmented mutation from B+. The B+ were actually the first I ever grew, and I kept growing them for almost 20 years before they produced the first couple dark, hairy capped fruits that became El Choco. This happened at a time when albino mushrooms were really starting to become popular, so the idea of isolating darker traits seemed like a good idea…for the next couple of years, I took spores from the darkest cap in each grow to start the next one. Over time, the pigmentation continued to darken, but they also picked up other traits along the way….slower, dense growth, meaty cap domes, and a significant kick.
Because of its unique traits, El Choco has found its way into a number of crosses: Chocolate Krinkle, Chocolate Gumby, ChocoTAT, ChocoMak, Mr Peanut, Heimdall, and Chocolate Thai, as well as producing an albino offshoot El Blanco, and a pigmented semi-revert labeled Bsquared.