Dried Tangerine Peel (Chen Pi): Grades, Age and Buyer Specifications

Dried tangerine peel — chen pi (陈皮) — is one of the few Chinese herbs priced by age as much as by grade. Two lots with the same appearance on a price list can sit far apart depending on the year of harvest and on whether the peel comes from Xinhui in Guangdong or from a standard mandarin-growing region. This guide sets out what those differences mean in practice, which standards a specification should reference, and what to write into an enquiry so that quotes from different suppliers can be compared.

Aile Herb supplies chen pi as a food-grade herbal ingredient and as a decoction piece, in 1-year, 3-year, 5-year and 10-year lots, produced without sulfur fumigation. Xinhui-origin peel is available on request and priced separately. Origin, age, quantity and the documents available are confirmed per enquiry and per batch.

What chen pi is, and the two names that matter

Chen pi is the dried, aged peel of the mandarin orange, Citrus reticulata Blanco and its cultivated varieties; the Chinese Pharmacopoeia names ‘Chachi’, ‘Dahongpao’, ‘Unshiu’ and ‘Tangerina’ among them. The monograph recognises two commercial forms:

• Chen pi (陈皮) — peel from mandarin varieties grown across southern and eastern China (Zhejiang, Fujian, Jiangxi, Sichuan and others). Thicker peel (1–4 mm), usually broken into several irregular pieces.
• Guang chen pi (广陈皮) — peel from Guangdong, typically the ‘Chachi’ variety (茶枝柑). Thinner peel (about 1 mm), cut so that three lobes stay joined, with large oil glands that show clearly against the light.

“Xinhui chen pi” is a geographical indication product, not a pharmacopoeia category. Under the local GI standard, it is peel from ‘Chachi’ mandarins grown and aged inside the defined area of Xinhui District, Jiangmen, for at least three years; younger material is “gan pi” (柑皮), mandarin peel. The GI standard’s harvest types (green, semi-red and red peel, by ripeness at picking) are its own classification and are separate from the pharmacopoeia’s definitions.

For most food and tea applications, the difference between the two forms is aroma and price rather than compliance. Both are the same species, both are on China’s food-medicine homology list (the 2002 list uses the name 橘皮, mandarin peel), and both fall under the same pharmacopoeia monograph.

Xinhui versus standard chen pi

Whether a blend needs Xinhui peel depends on the formula and how it is brewed; the practical test is a side-by-side sensory comparison in the buyer’s own recipe. A buyer selling chen pi on its own, or making an origin claim on the pack, needs the GI documentation, not just the word “Xinhui” on an invoice.

What aging changes, and what it does not

Chen pi is stored dry, turned and sun-aired periodically, and sold by age. The Xinhui GI standard sets the storage conditions: ventilated, humidity not above 70%, temperature not above 35 °C, with pest and mould controls.

In general terms, young peel is brighter in colour with a sharper citrus-oil aroma, and older peel is darker with a rounder, softer aroma. These are tendencies, not a scale for reading age off a sample.

Age is a documentation question, not a laboratory one. A routine COA, or a single hesperidin result, does not establish the year of harvest on its own. Studies of chen pi in storage report different trends in marker compounds depending on sample and conditions, so a compound figure cannot be turned into a year count. Age rests on batch identity plus harvest and storage records; where a buyer needs more, specialised authentication is a separate exercise. Ask what records the supplier can actually provide for the lot being quoted.

Which standards should your specification reference?

Food use, decoction-piece use, the Xinhui GI product and the destination market’s import rules are four different frameworks. A specification should say which one applies; one table cannot replace another.

Aflatoxin is one of the key risks for a material that is stored for years; a lot that was dried or stored badly at any point can fail. Ask for aflatoxin on every batch COA, not only on the first one.

Sulfur. Some producers fume young peel with sulfur to keep the colour bright and stop mould during the first drying. Two different things are worth separating in a specification: a process statement that the peel was not sulfur-fumigated, and an SO₂ residue result on the batch COA. Aile Herb’s chen pi is produced without sulfur fumigation; an SO₂ residue test can be added to the batch COA on request so that the buyer has the figure as well as the statement.

What to put in a specification

A chen pi specification that lets suppliers quote against the same thing has eight lines:

1. Form — whole peel pieces, cut strips, or slices; if cut, the width range.
2. Origin — standard (state the province if it matters) or Xinhui GI.
3. Age — 1, 3, 5 or 10 years, and which harvest and storage records you need.
4. Harvest type — red (mature) peel unless you specifically want green or semi-red, as described for Xinhui above.
5. Moisture — ≤ 13% as the ceiling; some buyers ask ≤ 12% for long sea transit.
6. Sulfur — not sulfur-fumigated, with SO₂ residue on the COA.
7. Tests per batch — moisture, hesperidin, aflatoxins, SO₂, heavy metals, pesticide residues, microbiology; state which limits (pharmacopoeia, destination market, or your own).
8. Packing — inner bag and carton weight; whether cartons must be lined against humidity.

Grade names (“premium”, “AAA”, “first grade”) mean different things to different suppliers. A piece-size range and a defect allowance are more useful than a grade word.

Sourcing notes for export buyers

• Regulatory status abroad. Dried mandarin peel has a long history of use as a food ingredient. The legal basis in a given market depends on the botanical identity, plant part, form (whole peel, cut, extract) and intended use, and has to be checked for that combination; in the US, for example, citrus peel appears in <a href=”https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-182/subpart-A/section-182.20″ target=”_blank” rel=”noopener”>21 CFR 182.20</a> as an extractive, and that entry by itself does not settle the status of whole dried peel in a tea. Our guide to US herbal tea ingredient compliance sets out the US framework.
• Pesticide residues. Mandarin orchards are sprayed, and the peel is where residues concentrate. The importer and the testing laboratory should agree the applicable commodity classification, residue limits and processing factors for the material and its use before a test panel is chosen; a generic citrus panel is a starting point, not a compliance conclusion.
• Sampling before bulk. For aged lots, a representative sample from the exact lot, tested at the buyer’s own laboratory and reviewed together with the batch documents, is the sound way to confirm the material before a container. The process is described in paid samples for lab testing.
• Availability and lead time. Standard 1-year peel is normally held in stock. Aged lots are held in limited quantities and are quoted on availability; Xinhui GI lots need extra time for documentation.

Frequently asked questions

Is Xinhui chen pi always better?
It is a different product with a protected origin, a single variety and a three-year minimum age. For blending it is a sensory and cost decision; for a stand-alone product with an origin claim it is the correct choice.

Can you prove the age of a lot?
Not by a routine test. We provide the harvest year and the storage records available from the producer for the lot quoted; the buyer reviews those with the sample. Treat any laboratory certificate that claims to “prove” a specific age with caution.

Is chen pi on China’s food-medicine homology list?
Yes, listed as 橘皮 (mandarin peel) on the 2002 list, and used as an ordinary food ingredient in China. That status does not carry over automatically to other markets; see the homology list guide.

What is the shelf life?
Aging years and shelf life after packing are different things. The best-before date and storage conditions for a packed product are set from the batch, the packaging and the buyer’s stability data, not from the age of the peel; moisture and aflatoxin results are part of that picture, not a substitute for it.

What quantities can you supply?
Standard 1-year peel from 1 kg per order. Aged and Xinhui lots are quoted per enquiry against available stock. Send form, origin, age, quantity and destination through our Chinese herbal slices page.