The vivid green pistachio you see on a gelato counter or a pastry is not an ordinary kernel. It comes from nuts picked early, then carefully peeled, and it is graded almost entirely on one thing: colour.
Where the green comes from
The colour of a pistachio kernel changes as it ripens. Early in the season the kernel is rich in chlorophyll and deeply green; as it matures, the green softens and a purple-brown skin develops. To capture the colour, growers pick a separate early crop, known in Iran as “kaal”, roughly a month before the main harvest, typically between July and August.
How green peeled kernels are made
- Early harvest: immature nuts are picked while the kernel is at its greenest.
- Shelling: the soft shells are removed.
- Blanching: the kernels are briefly treated with hot water to loosen the thin skin.
- Peeling: the skin is removed to reveal the green kernel underneath.
- Drying and screening: kernels are dried to a safe moisture level, sorted by colour, and screened for foreign matter.
The process is slow and the yield is small, which is why green peeled kernels are among the most valuable pistachio products.
Colour grades from S to D
Green kernels are graded by the intensity of their colour:
- S Ultra-dark green
- A Dark green
- B Bright green
- C Greenish-yellow
- D Yellowish
Colours are illustrative; grading is done against physical reference samples.
The darker the grade, the more striking the visual result and the higher the price. Many recipes do not need the top grade: a B grade can be ideal for fillings, while S and A are reserved for decoration where the colour is on show.
Typical specification points
- Moisture: 6% maximum
- Foreign matter: 0.1% maximum
- Colour grade: as agreed, S to D
- Screening: colour sorting plus checks for shell fragments and metal
- Aflatoxin: within EU limits (B1 at most 8 µg/kg, total at most 10 µg/kg)
Where green kernels are used
- Gelato and ice cream, both as flavour and as topping
- Pastry and patisserie, from macarons to baklava
- Confectionery and chocolate fillings
- Traditional sweets such as gaz and sohan
- Charcuterie, where green pistachio is a classic addition to mortadella
Green or regular kernels?
Regular kernels come from fully ripe nuts, keep their natural skin and offer a fuller, roasted-friendly flavour at a lower price. Green kernels are the choice when colour is part of the product. Both are on our Kernel page. If you need help choosing a grade, ask for samples of two neighbouring grades and compare them in your own recipe.
