Kitchen Chemistry: How to Actually Calculate Your Homemade Edible Doses (Without Guessing)
There's a rite of passage that almost every cannabis consumer goes through at least once: eating a homemade edible, waiting an hour, deciding it's not working, eating another one, and then spending the next six hours on the couch questioning their life choices. Sound familiar?
Homemade edibles are one of the most beloved corners of cannabis culture. They're cost-effective, customizable, and honestly kind of fun to make. But they're also one of the most common sources of accidental overconsumption — not because people are careless, but because the math involved is genuinely tricky. Let's break it all down.
Why Homemade Edibles Are So Unpredictable
Commercial edibles sold at your local dispensary go through rigorous lab testing. Every gummy, every chocolate bar, every capsule is tested for potency and required to meet specific milligram tolerances. When the package says 10mg THC per piece, that number has been verified.
Your kitchen doesn't have a gas chromatograph. And that's totally fine — but it does mean you're working with a lot more variables.
Here are the big ones:
Flower potency varies. That eighth of flower you're working with might say 22% THC on the label, but home-grown cannabis or flower without detailed lab data could be anywhere from 12% to 28%. Even dispensary flower can vary slightly from batch to batch.
Decarboxylation isn't always complete. Raw cannabis contains THCA, not THC. Heat converts THCA into the psychoactive THC we're after — a process called decarboxylation. If your oven runs hot or cold, or if your timing is off, you might not convert as much as you think. A general rule of thumb: expect about 75–88% conversion efficiency under ideal home conditions.
Infusion isn't 100% efficient either. When you infuse butter or oil, not all of the available THC binds to the fat. Depending on your method — stovetop, slow cooker, or dedicated infuser — you might capture anywhere from 60% to 90% of what was theoretically available.
Mixing is messier than it seems. Even after a thorough stir, THC doesn't distribute with perfect uniformity in a batter. One brownie in your batch might have twice the potency of the one next to it. This is called dose variance, and it's one of the biggest practical safety issues with homemade edibles.
The Basic Potency Formula
Okay, let's do some actual math. Don't worry — it's simpler than it sounds.
Here's the formula:
Total THC available (mg) = Weight of flower (grams) × THC% × 1000 × Decarb efficiency × Infusion efficiency
Let's walk through a real example.
Say you're using 7 grams of flower labeled at 20% THC.
- 7g × 0.20 = 1.4g of THC
- Convert to milligrams: 1.4g × 1000 = 1,400mg of THC (theoretical maximum)
- Apply decarb efficiency of 80%: 1,400 × 0.80 = 1,120mg
- Apply infusion efficiency of 70%: 1,120 × 0.70 = 784mg of THC in your infused butter or oil
Now say that infused butter goes into a batch of 24 brownies. Divide 784mg by 24 and you get roughly 33mg per brownie — a hefty dose for most people.
If you want a more moderate 10mg dose per piece, you'd either use less cannabis, make a larger batch, or cut each brownie into thirds.
Common Dosing Mistakes (And How to Avoid Them)
Skipping decarboxylation. This is the most common rookie mistake. You can't just melt butter and dump raw ground flower into it and expect full potency. Decarb your cannabis first: spread it on a baking sheet and bake at 240°F for 40 minutes before infusing.
Using too-high heat during infusion. THC degrades at high temperatures. Keep your infusion below 200°F. Low and slow wins every time — a slow cooker on low for 4–8 hours is a reliable method.
Not accounting for the math. A lot of people eyeball their flower amount, forget to factor in efficiencies, and end up with something way stronger or way weaker than intended. Take five minutes to run the numbers before you start.
Inconsistent mixing. After adding your infused fat to your batter, stir more than you think you need to. Then stir again. This is the best low-tech way to reduce dose variance across your batch.
Why Commercial Edibles Feel More Consistent
This isn't a knock on your homemade creations — it's just the reality of scale and testing. Dispensary edibles are produced in controlled environments with equipment that ensures uniform mixing and precise portioning. They're tested by third-party labs before they hit shelves. And in most legal states, they're required by law to stay within a certain percentage of the labeled potency.
If you're new to edibles, or sharing them with someone who has a low tolerance, commercial products are genuinely the safer starting point. Once you know how your body responds to, say, a 5mg gummy, you'll have a much better personal baseline for evaluating your homemade batches.
Troubleshooting a Weak Batch
Made a batch and it barely did anything? A few possibilities:
- You skipped or rushed decarboxylation. This is the most likely culprit.
- Your flower was lower potency than expected. Especially common with home-grown cannabis or older, improperly stored flower.
- Your infusion temperature was too low. Butter or oil that never got warm enough won't extract well.
- You didn't use enough fat. THC needs fat to bind to. If your recipe uses very little butter or oil, the infusion concentration will be lower.
If your batch is weak but not useless, you can always eat a larger portion — just go slowly and give it 90 minutes to two hours before deciding it's not working.
Storage and Safety: Don't Skip This Part
This matters a lot, especially if you live with other people, have kids, or host guests.
Label everything clearly. Use masking tape and a marker: "CANNABIS EDIBLES — CONTAINS THC" with the estimated dose per serving. Put it on the container, not just the shelf.
Store in child-resistant containers. Resealable bags are not enough. Use a lockbox or a container with a child-resistant lid.
Keep them in a dedicated spot — separate from your regular snacks. Mixing up the regular brownies and the special brownies is a genuinely dangerous mistake that happens more often than people admit.
Refrigerate or freeze for long-term storage. Edibles can go stale or moldy at room temperature over time. Wrapped individually and frozen, most baked edibles hold up well for a month or more.
The Bottom Line
Homemade edibles can be a genuinely rewarding part of your cannabis lifestyle — economical, creative, and deeply satisfying when they come out right. But they require a little more respect and preparation than a lot of people give them. Run the math, decarb properly, infuse carefully, and label your stuff like a responsible adult.
And if you're ever in doubt about potency? Start low. Wait longer than you think you need to. Your couch will still be there in two hours.
