13 October 2020 Decarboxylating Marijuana (Pressure Canner) Posted on October 13, 2020 by Durgan 13 October 2020 Decarboxylating Marijuana/ 13 October 2020 Decarboxylating Marijuana Decarboxylation marijuana. Marijuana usually needs decarbonylation prior to utilizing. My method is not unknown but seems to be rarely used. It work fine with little hassle. I use pressure canner aften and and am an expert in its use. I usually work with 30 grams of home grown material. Method. Raw quality product about 30 gram.Remove from support substrate and scissor into small pieces. Place in a liter jar and finger tighten the cap. Place in pressure canner and pressure can at 15 PSI for 40 minute.Done properly the jar material reaches 240F for 40 minutes. Let cool to room and store in freezer or refrigerator.Perfectly Decarboxylated.