Guide · Buyer guides
Buying THCA by the pound: five checks on every lot
Before you buy a pound of THCA flower, check five things against the lot itself: a certificate of analysis (COA) that names that exact lot, the total THC figure, moisture (water activity of 0.55–0.65 aw), how the flower was trimmed, and its grade and bud-size mix. A pound that fails any one of them costs more per usable gram than its price says.
Reviewed 2026-10-03. Not legal advice.
The five checks at a glance
| Check | Ask the seller for | Pass | Stop when |
|---|---|---|---|
| COA | Lab PDF, sample ID, client lot, test date | Client lot on the COA = lot on the listing = lot on the bag | No lot number, or the COA names another product |
| Total THC | THCA %, delta-9 THC %, basis | You can reproduce total THC with 0.877 × THCA + delta-9 | One unlabeled “THC” figure, no basis stated |
| Moisture | Water activity (aw) or loss on drying (%) | 0.55–0.65 aw | Above 0.65 aw, or no figure and no willingness to measure |
| Trim | Hand or machine; stem policy | Stems cut flush, sugar leaf removed | Long stems or fan leaf in the bag |
| Grade and size | Grow method; size breakdown by weight | Grade named; share of small buds disclosed | “Mixed” with no breakdown |
1. The COA must name this lot
A COA is evidence about one sample from one lot. It proves nothing about any other lot. Read three fields first: the lab’s sample ID, the client lot (or batch) number, and the date the sample was taken. The client lot number must match the lot on the listing and the lot printed on the bag that arrives.
A COA without a lot number proves only that some flower, somewhere, was tested. A COA dated many months before the sale proves less each week. THCA slowly converts to delta-9 THC with heat and time, and terpenes evaporate.
Ask for the full panel, not potency alone: pesticides, heavy metals, microbials, mycotoxins and water activity. Many hemp COAs stop at potency. The federal hemp program requires a pre-harvest THC test from growers; it does not require a contaminant panel on the finished flower. The step-by-step method for checking a lab and a lot is in How to verify a supplier COA.
2. Total THC: do the arithmetic yourself
Total THC is the delta-9 THC a lot would hold if all of its THCA converted. Labs compute it as:
Total THC = delta-9 THC + (0.877 × THCA)
The factor 0.877 is the ratio of the molecular weights of THC and THCA (314.5 ÷ 358.5). The difference is the carboxyl group that leaves as CO₂ when THCA is heated. USDA’s hemp rule defines total THC this way, on a dry-weight basis (7 CFR 990.1).
| THCA % | Delta-9 THC % | 0.877 × THCA | Total THC % |
|---|---|---|---|
| 18.00 | 0.15 | 15.79 | 15.94 |
| 24.00 | 0.20 | 21.05 | 21.25 |
| 30.00 | 0.25 | 26.31 | 26.56 |
Two consequences for a buyer:
- Compare lots on total THC, not THCA. THCA % reads about 14% higher than the total THC it produces. A “30% THCA” lot delivers 26.56% total THC in the example above.
- Total THC is the figure federal law will use. As of 3 October 2026, the federal hemp definition tests delta-9 THC alone, at no more than 0.3% on a dry-weight basis (7 U.S.C. 1639o). From 2026-12-11 (P.L. 119-37 §781; date set by H.R. 6500) the test becomes total THC, THCA included (CRS IF13136). Every lot in the table is far above 0.3% total THC. None of them is hemp after that date.
Check the basis line. Labs report potency either on a dry-weight basis or “as received”. To convert as-received to dry weight, divide by (1 − moisture fraction). Example: 20.00% total THC as received at 10.0% moisture equals 22.22% on a dry-weight basis. Compare two lots only on the same basis.
3. Moisture: water activity of 0.55 to 0.65
Water activity (aw) measures how freely the water in flower can move. It predicts mold better than moisture percent does. ASTM D8197 sets 0.55–0.65 aw for dried cannabis flower: above 0.65 the risk of mold rises; below 0.55 the flower turns brittle and breaks in handling. The companion method, ASTM D8196, covers how to measure it.
Moisture is also a price question, because water is sold as weight. The dry matter in a bag stays constant while water leaves:
weight after = weight before × (1 − moisture before) ÷ (1 − moisture after)
| Packed at (moisture) | Measured at | 453.6 g becomes | Weight lost |
|---|---|---|---|
| 12% | 11% | 448.5 g | 5.1 g |
| 12% | 10% | 443.5 g | 10.1 g |
| 13% | 10% | 438.5 g | 15.1 g |
| 14% | 10% | 433.4 g | 20.2 g |
A pound packed wet loses weight in transit and on the shelf, and each dry gram costs more. A pound packed too dry has already lost terpenes the COA no longer describes. Weigh every bag on arrival on a scale you trust, and write the figure down with the date.
4. Trim and stems
- Hand trim. Sugar leaf is cut away bud by bud. The bud keeps its shape and its trichomes. It takes more labor, which the price reflects.
- Machine trim. A tumbler or blade trimmer is faster. It can knock trichomes off and leave buds rounder and flatter-faced.
- Stems. Stems are weight that does not smoke. Ask for the stem policy in writing.
A simple stem test on arrival: take a random 28 g sample from the bag. Cut every stem that runs past the base of the bud. Weigh what you removed. The result is the stem share of the lot in grams per ounce, and you can hold the next lot to the same number.
Fan leaf in a pound bag is shake that was sold at flower weight. Note it, photograph it and raise it with the seller before mixing the bag into stock.
5. Grade and bud size
Grade usually names how the plant was grown: indoor, greenhouse or light-dep. Size is a separate axis. Small buds come from every grow method. Ask for both, and ask for the size mix by weight, for example: over 3 cm, 1.5–3 cm, under 1.5 cm. A pound that is 40% buds under 1.5 cm is a different product from one that is 10%, even at the same grade and the same COA.
How each grade is grown and what to check for each one is in Indoor, greenhouse, light-dep and smalls.
Receiving a pound: the arrival routine
- Photograph the sealed bag with its label before you open it.
- Read the lot number on the label against the COA.
- Weigh the bag sealed, then tare a clean container and weigh the flower net.
- Smell and look. A musty or hay smell, white or grey fuzz, or webbing means stop: keep the bag apart from other stock and call the seller.
- Measure water activity if you own a meter.
- Reseal it, and keep it sealed, dark and at a steady room temperature until you open it.
Where a pound can be delivered
Two lanes exist, and they are often confused.
- Hemp-retail lane. High-THCA flower sold as hemp, outside a licensed cannabis channel. Our count, 2026-10-03: open in 5 states, open with conditions in 3, contested in 6, closed by state law in 36 states and D.C.
- Licensed-dispensary lane. In states with adult-use cannabis, the same kind of flower is sold lawfully by state-licensed dispensaries under state law. Licensed stores operate today in 23 adult-use states, 16 of them closed to hemp flower. Virginia’s stores open 2027-07-01.
The federal change on 2026-12-11 applies in every state. After that date, flower above 0.3% total THC leaves the hemp-retail lane everywhere, unless Congress moves the date again. H.R. 6500 also funds the government only through 2026-12-11, so a further extension is possible. It is not promised.
We accept Order Requests from every US address. On the call, an Operator says plainly when an order cannot be filled for an address. You remain responsible for the products being lawful where you take delivery.
How a pound order runs in this store
- Add a lot to the cart as a Half Pound (HP) or Pound (LB).
- Send an Order Request with your Payment Preference. Nothing is charged online.
- An Operator calls, checks each line against live lot stock, and agrees delivery and payment with you.
- Stock is reserved only when the order is confirmed.
Every product page links the COA for its lot. Questions about a certificate come to us with the lot number. Buying five pounds or more: it is the same Order Request at the listed prices, and the Operator confirms stock for the full weight on the call. See Large orders.
Sources
- 7 CFR 990.1: USDA definitions of total THC and decarboxylation (accessed 2026-10-03).
- 7 U.S.C. 1639o: federal hemp definition.
- CRS IF13136, 2026-08-17: P.L. 119-37 §781 and its effective dates.
- White House, 2026-09-02: H.R. 6500 signed into law.
- ASTM D8197: water activity range for dried cannabis flower.
Questions
What should a COA show before I buy a pound of THCA flower?
The lab name and accreditation, a sample ID, the client lot number that matches the lot you are buying, the test date, THCA and delta-9 THC on a stated basis, and ideally a full contaminant panel (pesticides, heavy metals, microbials, mycotoxins, water activity).
How is total THC calculated?
Total THC = delta-9 THC + (0.877 x THCA), on a dry-weight basis. A lot with 24.00% THCA and 0.20% delta-9 THC has 21.25% total THC.
What moisture level should bulk THCA flower have?
Water activity between 0.55 and 0.65 aw, the range in ASTM D8197 for dried cannabis flower. Above 0.65 aw raises mold risk; below 0.55 aw the flower turns brittle.
Is a pound of THCA flower still hemp after December 11, 2026?
Not if it is above 0.3% total THC. From 2026-12-11 (P.L. 119-37 section 781; date set by H.R. 6500) the federal hemp test counts THCA. High-THCA flower then counts as marijuana under federal law in every state.