How to Read a Matcha COA: Pesticides, Heavy Metals, Microbiology & More
A matcha COA (Certificate of Analysis) is the per-lot laboratory report that proves the exact batch you are buying was tested and met its agreed limits for pesticide residues, heavy metals, microbiology, and physical-chemical quality. To read one quickly, match the batch/lot number on the COA to the number on the goods, confirm it comes from an accredited lab with a recent test date, then check each hazard panel line by line against your own specification — not just against a ‘pass’ stamp.
This guide walks through a matcha COA section by section — pesticides and MRLs, heavy metals, microbiology, and physical-chemical parameters — with the specific buyer red flag to watch for in each. It also explains the reporting-limit trap that makes a ‘not detected’ result meaningless if you read it wrong, and gives you a red-flag checklist and a set of supplier questions you can use before you commit volume. Regulatory limits are cited to primary sources so you can verify them yourself.
Key Takeaways
- A matcha COA is per-lot proof, not a brochure: the batch/lot number on it must match the number on your goods, or it is not evidence for your shipment.
- A COA reports measured results for a specific lot; a specification sheet defines the constant limits every lot must meet — you read them together, line by line.
- Every hazard panel — pesticides, heavy metals, microbiology — should show actual measured values, the test method, and the lab’s reporting limit, not just ‘pass’.
- A ‘not detected’ result only proves compliance when the lab’s reporting limit sits below your specification limit.
- Insist on an accredited lab (ISO/IEC 17025) and a recent test date; an undated COA from an unnamed lab is a red flag, not a document.
Researched and reviewed by the Matcha Times Editorial Team, operated by the Japan Matcha Export Organization (JMEX). Last reviewed: September 13, 2026. See our Editorial Policy and Sources & Methodology. Found an error? Tell us.
What a matcha COA is (and how it differs from a spec sheet)
A Certificate of Analysis is the document a supplier issues for a specific production lot, listing the tests run on that lot and the results they produced. It is the quality-assurance backbone of any serious matcha purchase — wholesale, OEM, or private label — because it turns ‘trust us, it is clean’ into a dated, measurable record you can audit and archive with the shipment.
It is easy to confuse a COA with a specification sheet, but they do different jobs. The specification sheet defines the agreed grade and the constant limits — the ceilings for contaminants, the physical targets, the packing and storage rules — that stay the same across every lot. The COA is the per-lot evidence that one specific batch actually met that spec. You need both, and you read them side by side.
| Aspect | Specification sheet | Certificate of Analysis (COA) |
|---|---|---|
| What it is | The agreed standard for the product | Test evidence for one production lot |
| Changes per lot? | No — constant until renegotiated | Yes — issued fresh for each batch |
| Carries a batch/lot number? | No (it defines the product) | Yes — must match your goods |
| Shows measured values? | No — states limits/targets | Yes — actual results vs limits |
| Typical fields | Grade, origin, cultivar, particle size, moisture, contaminant & micro limits, packing | Pesticides, heavy metals, microbiology, physical-chemical results, lab, dates, method |
Read the two together: the spec sheet is the promise, the COA is the proof. The single most useful habit is line matching: pull the spec limit and the COA’s measured value next to each other and confirm the result sits inside the limit. A COA that only restates the limits without giving you the measured numbers is describing the promise again, not proving it.
For Companies Seeking Matcha Powder
We source matcha from Japan’s premier production regions including Kyoto Uji, Kagoshima, Fukuoka, and Shizuoka, offering comprehensive grade ranges from organic JAS-certified ceremonial grade to processing-grade matcha.
Common Challenges:
- “We have projects but cannot secure stable matcha supply…”
- “We want to incorporate matcha into new café menu items!”
If you face these concerns, consult with Matcha Times. Feel free to contact us for initial inquiries.
＼Read Also／
How to read a matcha COA, section by section
Work through the COA in the order below. For each panel, do the same three steps: read the measured value, compare it to your specification limit, and check that the lab’s reporting limit is low enough for the comparison to mean anything. The buyer red flag under each section is the thing that most often turns an impressive-looking document into a worthless one.
Pesticide residues and MRLs
Matcha is a whole, ground leaf, so pesticide residues are concentrated rather than washed away — this panel matters. A credible screen tests a broad multi-residue panel and compares each result to the maximum residue level (MRL) for your destination market. The EU sets MRLs under Regulation (EC) No 396/2005, with a default level of 0.01 mg/kg where no specific MRL exists; Japan’s Positive List system applies a uniform limit of 0.01 ppm for agricultural chemicals with no established limit. The same lot can pass one market and fail another, so confirm which market’s MRLs the COA was read against.
Red flag: a COA that lists only a handful of residues, or reports the panel against no named market standard. A narrow screen can ‘pass’ simply because it never looked for the residue that matters to you.
Heavy metals
Because tea plants take up metals from soil, a matcha COA should carry a heavy-metals panel — at minimum lead, cadmium, arsenic, and mercury — with specific measured values, not a bare pass. The US FDA treats these as environmental contaminants in food and, through its Closer to Zero program, is setting action levels to drive dietary exposure as low as practicable; note that an action level is guidance, not a ‘safe’ threshold. Compare each metal to your own specification limit and to your destination market’s requirements.
Red flag: results shown only as ‘ND’ or ‘pass’ with no number and no reporting limit — you cannot tell whether the lab could even detect a level that would breach your spec.
Microbiology
The microbiology panel confirms the powder is safe and was handled hygienically. Expect indicators such as total plate count, yeast and mold, coliforms or E. coli, and pathogen tests such as Salmonella. Each should show a measured count against a stated limit, with the method noted.
Red flag: a microbiology section that names organisms but omits either the measured counts or the limits, so you cannot see how close the lot ran to the ceiling.
Physical and chemical parameters
Beyond safety, the COA should confirm the lot is the matcha you specified. Typical fields include moisture, particle size (often expressed as D50 and D90), color measured as L*a*b* values, and total ash. These are buyer-defined numbers — you set the target range on your spec sheet, and the COA confirms the lot lands inside it — so treat any ‘standard’ figure a supplier quotes as a starting point to agree, not a universal truth.
Red flag: physical-chemical values that drift lot to lot with no agreed range, which shows up later as visible changes in color or texture in your finished product.
Batch, laboratory and dates
Finally, read the header and footer, not just the results table. The COA must name the batch/lot number that matches your goods, identify the testing laboratory, and carry a recent test date. An ISO/IEC 17025 accredited laboratory has demonstrated its technical competence for the methods it reports, which is why buyers and regulators accept its data.
Red flag: an undated COA, a missing or mismatched lot number, or an unnamed ‘internal’ lab. If you cannot tie the document to this shipment and to a competent lab, it is not evidence.
＼Read More／
The ‘not detected’ trap: reporting limit vs specification limit
‘Not detected’ (ND) sounds like the best possible result, but on its own it means very little. For any trace analyte — a heavy metal, a pesticide, a microbial count — ND only means the lab did not find the substance above its reporting limit. If that reporting limit is higher than the limit you care about, an ND result does not prove your spec was met.
The rule to remember: an ND is only meaningful when the reporting limit sits below your specification limit. If your lead limit is stricter than the lab’s reporting limit, the lab literally could not have seen a breach, so its ND tells you nothing about compliance. Always read the reporting limit next to your specification limit before you accept an ND, and ask for a method with a lower limit of quantification when the numbers are close.
Buyer red-flag checklist for a matcha COA
Run every incoming matcha COA through this quick checklist before you approve a lot. If any item fails, treat the document as incomplete and go back to the supplier rather than waving the shipment through.
- The batch/lot number on the COA matches the number physically on the goods and on the packing list.
- The COA gives actual measured values for each hazard, not just ‘pass’ or ‘ND’.
- Each result is compared to a named limit (your spec and/or your destination market’s MRLs).
- The lab’s reporting limit is below your specification limit for every ND result.
- The pesticide screen is a broad multi-residue panel read against a stated market standard, not a token few residues.
- The testing laboratory is named and accredited and the report carries a recent test date.
- The COA is issued for this production lot, not a generic once-a-year certificate reused across lots.
Matching COA specs to your application
The COA fields that matter most depend on what you make. A COA is not one-size-fits-all: decide which lines are make-or-break for your product before you set your specification limits, so you are testing against the risks that actually affect your finished product.
| Application | COA lines to weight most | Why |
|---|---|---|
| Latte / beverage (café, RTD) | Color L*a*b*, particle size, microbiology | In-cup color and smooth texture drive the product; beverages raise hygiene stakes |
| Confectionery / baking (OEM) | Color stability, moisture, heavy metals | Color must survive heat; moisture affects shelf life; metals concentrate in whole-leaf powder |
| Health / wellness & protein | Heavy metals, pesticides, microbiology | High-dose, health-positioned products face the strictest contaminant scrutiny and labeling |
| Private-label retail | Full panel + labeling / organic docs | You own the brand claim, so you own the compliance and organic/labeling evidence |
Whatever you make, keep the export-compliance lines in view too: residue and heavy-metal results, organic or other certification documents, and destination-market labeling all ride alongside the COA in a real shipment. Define these before you scale, not after a customs query.
Testing lead time and cost realities
Lab testing takes time and money, and both scale with how much you ask for. A broad pesticide screen plus heavy metals, microbiology, and physical-chemical work is more thorough — and slower and more expensive per lot — than a thin panel, which is exactly why a suspiciously cheap or instant COA deserves scrutiny. Testing lead time is added to milling and shipping lead time, so a full per-lot COA can add its own weeks to a schedule; build that into your timeline rather than discovering it at reorder.
Keep cost honest, too: testing fees, panel breadth, and turnaround vary by lab and market, so treat any figure as a current quote to request for your exact panel and volume rather than a fixed number. The goal is not the cheapest COA; it is the right panel, read against the right limits, for the risk your product actually carries.
From the exporter’s perspective
From the export side, the shipments that clear cleanly are the ones where the COA and the specification sheet were agreed before the first lot, not improvised at the port. When a buyer defines the panels, the limits, and the destination-market MRLs up front, JMEX can arrange per-lot testing at accredited laboratories, match every result to the agreed spec, and keep the batch numbers, residue analyses, and organic documentation aligned so the paperwork tells one consistent story from farm to customs.
Questions to ask your matcha supplier
Before you commit volume, put these questions to your matcha supplier about their COA and testing:
- Do you issue a COA per lot tied to the exact lot I receive, with a batch number I can match to the goods?
- Which panels do you run — how broad is the pesticide screen, and which heavy metals and microbiology do you cover?
- Against which market’s MRLs do you read the pesticide results (EU, Japan, US, or my destination)?
- Is the testing done by an accredited (ISO/IEC 17025) laboratory, and can you share the report with method and reporting limits?
- Can you meet a written specification sheet — grade, origin, particle size, moisture, color, contaminant limits?
- What organic, halal, or other certification and labeling documents can you provide for my market, alongside the COA?
- What is the realistic lead time in weeks from order to shipment, including testing and export documentation?
A supplier who can answer these and put the spec in writing gives you a COA you can actually rely on — and protects you from the silent quality drift that quietly appears between a great first lot and a disappointing reorder.
Sources & Methodology
This article synthesises official government and international-standards sources into a practical, buyer-side method for reading a matcha COA; it reports no proprietary buyer statistics or in-house test numbers because we hold no publishable original dataset on matcha COAs. The only hard limits asserted — the EU 0.01 mg/kg default MRL and Japan’s 0.01 ppm uniform limit — are attributed inline to their primary sources and dated. Matcha spec values (moisture, particle size, color, microbiology counts) are treated as buyer-defined targets to agree on a specification sheet, not universal figures, and testing cost and lead time are kept qualitative because they vary by lab, panel, and market.
- European Union — Regulation (EC) No 396/2005 (pesticide MRLs) — the EU framework for pesticide maximum residue levels and the 0.01 mg/kg default level where no specific MRL exists (accessed 2026-09-13; EU primary legislation (EUR-Lex))
- Japan MHLW — Positive List system for agricultural chemical residues — Japan’s residue framework and the 0.01 ppm uniform limit where no MRL is established (accessed 2026-09-13; official Japanese government (Ministry of Health, Labour and Welfare))
- U.S. FDA — Environmental Contaminants in Food — the US regulator’s treatment of heavy metals (lead, arsenic, cadmium, mercury) as environmental contaminants in food (accessed 2026-09-13; U.S. government food-safety regulator)
- U.S. FDA — Closer to Zero — the US program setting action levels to reduce dietary exposure to toxic metals, and the meaning of an action level (accessed 2026-09-13; U.S. government food-safety program)
- ISO/IEC 17025 — testing and calibration laboratories — the international standard for laboratory competence that underpins a credible, defensible COA (accessed 2026-09-13; international standards body (ISO))
Why Buyers Choose JMEX (Japan Matcha Export Organization)
For importers, wholesalers, and OEM buyers who need the paperwork to hold up at customs and in an audit, JMEX (Japan Matcha Export Organization) is a wholesale and export partner focused on shipping Japanese matcha overseas. It coordinates origin and grade selection, specification design, per-lot quality assurance (COA), certifications, and export documentation as one continuous flow, built for export from the start.
Because JMEX designs matcha to a written specification sheet, arranges per-lot testing at accredited laboratories, reads pesticide results against the destination market’s MRLs, and keeps batch numbers, residue analyses, and organic documentation aligned, buyers get a COA they can actually rely on rather than a generic certificate. With an export track record to 43 countries, JMEX has prepared compliant COA and specification documentation for many destination markets, and helps first-time importers and private-label buyers set the right panels and limits before the first lot ships.
Frequently Asked Questions
Quick answers to the questions buyers ask most about reading a matcha COA.
What is a matcha COA?
A matcha COA (Certificate of Analysis) is the per-lot laboratory report proving that a specific production batch of matcha was tested and met its agreed limits for pesticide residues, heavy metals, microbiology, and physical-chemical quality. It carries a batch/lot number, measured results, the test method, the laboratory, and the test date — and it must match the goods you actually received.
What should a matcha COA include?
A complete matcha COA includes a pesticide-residue screen, a heavy-metals panel (lead, cadmium, arsenic, mercury), a microbiology panel (total plate count, yeast and mold, coliforms/E. coli, Salmonella), and physical-chemical parameters such as moisture, particle size, color (L*a*b*), and ash. Each result should show an actual measured value against a stated limit, plus the batch number, lab name, method, and date.
What is the difference between a COA and a specification sheet?
A specification sheet defines the constant standard — the grade, physical targets, and contaminant limits every lot must meet — while a COA is the per-lot evidence that one specific batch met that standard. The spec sheet is the promise; the COA is the proof. You read them together, matching each measured value on the COA to its limit on the spec sheet.
How do I verify a matcha COA is legitimate?
Confirm the batch/lot number matches your goods, check that the report is from a named, accredited (ISO/IEC 17025) laboratory with a recent test date, and make sure each hazard shows a measured value and the lab’s reporting limit — not just ‘pass’ or ‘ND’. A generic, undated, or unnamed-lab certificate reused across lots is a red flag, not evidence.
How recent should a matcha COA be?
The COA should correspond to the actual lot you are buying, so its test date should be tied to that production batch rather than an old, one-time certificate applied to everything. If a supplier offers a single dated report for many shipments, ask for the per-lot COA for your specific batch instead.
Learn More About Global Matcha Trends at Matcha Times
Matcha Times is a specialist media platform covering the global matcha market — sourcing and wholesale, supply and pricing, trade and regulations, production and origins, and the companies shaping the industry.
From market analysis and price trends to café case studies and interviews with tea farmers, we help buyers, importers, distributors, and manufacturers stay ahead of where matcha is heading. Explore more and put the global matcha market to work for your business.
Conclusion
When origin, grade, and export conditions align, matcha becomes a stable revenue source. Start by defining your requirements and confirming quality with a sample.
Looking for wholesale or OEM matcha samples? Contact us — we will recommend the optimal origin and grade based on your application and target markets.
Related Articles
