Almost every chilli contract in the world quotes an ASTA colour value. And a surprising number of arguments between buyer and seller start because the two sides think it means different things.
This page explains what the number is, how the test works, why it drops on the way to you, and what to write in your contract so the figure means something when the container arrives.
What ASTA colour actually measures
ASTA stands for the American Spice Trade Association. The ASTA colour value tells you how much colour a chilli can give to your food. It does not tell you how red the chilli looks in the bag.
The test works like this. A lab takes a small sample and grinds it. The ground sample is mixed with acetone, a solvent. The solvent pulls the colour out of the chilli. The lab then puts the liquid into a machine called a spectrophotometer. That machine measures how much light the liquid absorbs. The result is turned into a single number.
So the number is about extractable colour. That is the colour your sauce, your snack coating or your spice blend will actually get.
This is why two lots can look the same on a table and test thirty points apart. It is also why holding an old sample next to a new delivery does not prove anything. Your eyes and the lab are not measuring the same thing.
Typical ASTA ranges for Indian chilli
India grows many chilli types. Three cover most of the export trade.
- Byadgi: roughly ASTA 60 to 80, sometimes higher. Very low heat. People buy it for colour. Our Byadgi chilli is graded on this number.
- Teja (S17): roughly ASTA 30 to 40, with 75,000 to 100,000 Scoville heat units. People buy it for heat. Our Teja chilli is graded on pungency first.
- Sannam (334): middle of the range on both colour and heat. A general purpose grade.
Colour and heat are two separate things. A chilli can be high in one and low in the other. Byadgi and Teja are the clearest example: they sit at opposite ends.
Colour and heat are contracted differently
Which number you should buy on depends on what you are making.
Paprika style products and oleoresin extraction are contracted on ASTA. The buyer wants colour and will pay for it.
Hot sauce and pickle production are contracted on Scoville. The buyer wants heat, and colour is secondary.
Many food manufacturers need both fixed. A snack seasoning may need a specific red and a specific burn. That is a blend, not a single variety. Our red chilli powder is built to an agreed ASTA and Scoville pair for exactly this reason.
A specification that says only “red chilli powder” has fixed neither. You will get whatever that season produced.
Colour falls during storage and shipping
This is the part that causes most disputes, and it is simple physics rather than anyone cheating.
Extractable colour breaks down when chilli meets light, heat and oxygen. It happens slowly, but it never stops.
A lot that tests ASTA 80 on the day it is packed can arrive noticeably lower after six weeks at sea. A container crossing the tropics gets hot inside. A container that sits in the sun at a port before loading gets hotter still. Both cost you colour.
Nobody falsified anything. The certificate was true on the day it was issued.
How much does it drop?
There is no single figure, because it depends on the route, the season, how the container was stuffed and how long the goods sat before and after. A drop of several points over a long tropical voyage is normal. A large drop usually points at heat exposure rather than at the original quality.
The useful response is not to argue about it afterwards. It is to decide, before the contract is signed, which point in the journey the number applies to.
Two ways to write ASTA into a contract
You have a choice, and both are valid. What matters is that you pick one and write it down.
- ASTA at shipment. The value is measured on the packed lot before loading. This is the common method. It is easy to verify and it is fair to both sides, because neither controls the voyage.
- ASTA at discharge. The value must still be met when the goods arrive. This shifts the risk to the supplier, and the price will reflect that. It is used where colour is critical and the buyer cannot carry the risk.
Most contracts use the first. If you use it, you should add a margin. If you need ASTA 70 in your factory, buy ASTA 80 at shipment. That gap is your protection against normal decay.
Always ask for the test date
An ASTA figure with no date attached tells you very little.
A certificate of analysis issued three months before despatch describes material as it was three months ago. The goods in your container have moved on since then.
Put this in the specification: “ASTA 70 minimum, tested within 14 days of despatch.” That sentence is enforceable. “Good red colour” is not.
Also ask for the method. ASTA method 20.1 is the standard one. If your supplier used a different method, the numbers are not directly comparable.
A short checklist
Before you confirm a chilli order, make sure your specification answers all of these:
- The ASTA value, written as a minimum rather than a target.
- The test method.
- When the test is done, and how many days before despatch.
- Whether the value applies at shipment or at discharge.
- The Scoville range, if heat matters to your product.
- The variety, or that a blend is acceptable.
- Moisture, usually 10 to 12 per cent maximum.
- Aflatoxin limits for your destination market.
The short version
ASTA is a lab measurement of extractable colour, not a visual grade. It falls during storage and transport, so the date of the test matters as much as the number.
Fix the number, the method, the test date and the measurement point in writing before you order. Do that once and you remove the most common chilli dispute in the trade.
If you are not sure which ASTA level your product needs, tell us what you are making and we will suggest a grade rather than sell you the highest number available.