Standardisation means making each batch of a herbal preparation the same strength as the last, and without laboratory measurement of the active compound it can only be approximated, never confirmed. Potency varies with species, plant part, season, growing conditions, drying and extraction, so a dose that worked once says little about the next batch. A rebuilding community can narrow the spread by fixing every input and pooling batches, and should treat the result as unknown strength all the same.
Part of Organic Chemistry
Controlling the variables of a plant preparation so batches resemble each other, and being honest about what that does and does not achieve.
Potency Has Many Sources Of Variation
The carrier’s tip box says it directly: without modern analytical equipment, standardisation is the biggest challenge, because every batch will be slightly different in potency. The reasons, each of which acts independently, are:
- Species and variety. Look-alike plants can carry very different amounts, or different compounds.
- Plant part. Leaf, root, bark and seed of the same plant can differ by large factors.
- Season and age. Compounds rise and fall through the year and with the age of the plant.
- Growing conditions. Soil, light, water and stress change what the plant makes.
- Drying and storage. Heat, light and time degrade many active compounds.
- Extraction. Solvent strength, particle size, time and temperature decide how much of what is present is recovered.
These multiply. The worked example in Alkaloid Extraction shows two modest ranges producing a six-fold spread.
What You Can Control
You can control inputs and you can record them. That narrows the spread; it does not measure the dose.
- A fixed recipe, written down: plant, part, weight, solvent, solvent strength, volume, time and temperature. Compare with the ratio logic in Tinctures and Extracts.
- A reference specimen of the plant, dried and labelled, kept for identification.
- Harvest at the same stage, and dry the same way.
- Batch records and a retained sample of each batch.
- Pooling. Blend several batches into one large lot and dose from the lot. It averages the weak with the strong.
What You Cannot Control
No bench test available to a community measures the amount of active compound. Weighing the dry extract measures yield, and yield is not potency: a heavy extract can be full of inert material. Taste and colour correlate loosely. The only direct “assay” is giving it to a person, which is not an acceptable way to standardise a narrow-margin medicine. For that reason this corpus does not publish a standardisation scheme for narrow-margin compounds: it would imply a certainty that does not exist. See Dosage and Safety.
Method: Making A Batch Record And Pooling
Step 1: Write the recipe before starting, and follow it exactly.
Step 2: Label the batch with date, plant, part, weights and who made it.
Step 3: Keep a small retained sample in a sealed, labelled vial.
Step 4: Pool batches only if they were made to the same recipe, then mix thoroughly before bottling.
Worked Example: What Pooling Does To The Spread
Use hypothetical strengths in arbitrary units. Four batches come out at 2, 3, 6 and 12. The strongest is 12 ÷ 2 = 6 times the weakest.
- Pool all four in equal volumes. Mean strength = (2 + 3 + 6 + 12) ÷ 4 = 23 ÷ 4 = 5.75.
- Every bottle drawn from the pool now has 5.75 units; the batch-to-batch spread inside the pool is gone.
Pooling removed the spread inside the lot, and left the question of whether 5.75 is the right strength entirely open. A second lot pooled from four other batches might come out at 3 or at 9. Pooling reduces variance between bottles; it cannot fix the average, and it can make a weak or a strong lot look reassuringly uniform.
Common Mistakes
- Treating a uniform lot as a correct lot. Uniform and correct are different properties.
- Standardising to the weight of dry extract. That is yield, not strength.
- Changing two variables at once between batches, so no change can be traced.
- Relying on a previous good result. A dose that worked once tells you little about the next batch.
Safety
Uniform strength is not safe strength
A pooled, carefully recorded batch can still be dangerously strong for a narrow-margin compound. Do not prepare or dose such compounds without tested published figures for the exact preparation, begin at the low end, keep lots labelled and locked up, and discard any lot whose plant identity is in doubt.
What’s Next
- Learn next: Tinctures and Extracts — a fixed-ratio preparation that is easier to record
- Combine with: Natural Pharmaceuticals — choosing compounds with a wide margin