Decarboxylation Explained: Why You Need to Heat Cannabis Before Cooking

## The Short Answer Decarboxylation (or "decarb") is the chemical process that converts THCA (the non-intoxicating acid form of THC in raw cannabis) into THC (the intoxicating form). Heat drives the reaction. For adults 21 and older cooking with cannabis at home, decarb is the step that turns "weed butter that does nothing" into "weed butter that works." ## What's Happening Chemically Raw cannabis contains THCA, not THC. THCA has a carboxyl group (-COOH) attached that makes it a larger molecule and prevents it from binding CB1 receptors strongly. When heated, THCA loses the carboxyl group as CO2 (that's the "decarboxylation"), becoming THC. This is why: - **Eating raw cannabis produces no high.** THCA in, THCA out. - **Smoking produces effects instantly.** Combustion decarboxylates and inhales simultaneously. - **Vaping produces effects instantly.** Heat decarboxylates; vapor delivers. - **Edibles require a prep step.** You need to heat the cannabis before mixing into a room-temperature medium. ## The Decarb Process Standard method for flower: 1. Preheat oven to 240°F (115°C). 2. Break flower into small pieces; spread on parchment-lined sheet pan. 3. Bake 30-40 minutes, stirring once. 4. Flower should turn slightly darker green/brown. 5. Let cool before using. Lower temperature for longer time is better than higher temperature for shorter time; the goal is complete decarboxylation without degrading the cannabinoids or terpenes. ## Why Not Higher Heat? Above about 320°F (160°C), THC begins degrading to CBN (which is much less intoxicating). Terpenes begin evaporating at much lower temperatures than that. A slow, low-temperature decarb preserves more of the original cannabinoid and terpene profile. ## Concentrates and Decarb Distillate, most concentrates, and activated products are already decarboxylated. They can be added directly to room-temperature medium without a decarb step. This is why distillate is the simplest starting point for cannabis cooking. Non-activated concentrates (some live resins, rosins) need decarb. Read the label. ## Ratio of Decarb Efficiency Complete decarboxylation has a theoretical maximum conversion of about 87 percent of THCA weight to THC weight (the 13 percent difference is the CO2 that leaves the molecule). home decarbs typically achieve 80-90 percent of this theoretical maximum. ## Dose Math Using Decarb For home cooking, if starting with 1 gram of 20% THC flower: - Raw THCA content: ~200 mg × 90% (because 20% is "total THC" which assumes decarb; actual THCA is a bit higher) ≈ 180 mg THCA. - After decarb: 180 mg × 0.87 ≈ 156 mg THC available. - After infusion into fat: typically 50-70% efficiency ≈ 80-110 mg THC in butter/oil. Err low when calculating your finished-product dose. See [cooking with cannabis](/blog/cooking-with-cannabis-beginner-recipes-and-dosing-tips-for-edibles-at-home). ## Common Mistakes - **Skipping the decarb step.** The most common "my edibles don't work" complaint. - **Too high heat.** Degrades cannabinoids before they can be used. - **Too short time.** Incomplete decarboxylation; weaker edibles. - **Uneven spread.** Flower on the edges decarbs faster than flower in the middle. ## Where to Go Next Related reading: [cooking with cannabis](/blog/cooking-with-cannabis-beginner-recipes-and-dosing-tips-for-edibles-at-home), [edibles 101](/blog/edibles-101-how-they-work-dosing-tips-and-what-to-expect), and [thca explained](/blog/thca-explained-what-it-is-and-why-its-trending). --- *This article is consumer education for adults 21+. Nothing here is medical, legal, or financial advice. Cannabis laws vary by state, always verify your state's current rules and, for health questions, consult a licensed clinician. For regulated New York retail, verify licensing via the OCM QR-code system at [cannabis.ny.gov](https://cannabis.ny.gov).*