How hazelnut kernel calibre is read
When you buy hazelnut kernels in bulk, the size is usually written as a range in millimetres, for example 9–11 mm or 11–13 mm. This size is called the calibre.
What the numbers mean
A calibre range describes the diameter of the kernels in the lot. A 11–13 mm range means the kernels are meant to measure between 11 and 13 millimetres across. A larger range generally means a larger kernel.
Kernels are sorted into calibres by passing them through calibrating equipment that separates them by size. The result is a lot of kernels that are more uniform than an unsorted harvest.
Why calibre matters to a buyer
Size affects how kernels behave in production. A buyer who roasts and sells whole kernels may choose differently from a buyer who will chop or grind them. Even sizing can also help roasting to be more even, because kernels of similar size heat at similar speeds.
The right calibre depends on your recipe, your equipment and your product. There is no single best size.
What to confirm in writing
Size ranges and the way they are measured can differ between suppliers and between markets. Before you order, ask the supplier to confirm:
- the exact calibre range, in millimetres
- what share of kernels outside the range, if any, is acceptable
- whether the figure applies to natural or roasted kernels
- how the lot will be checked and documented
Next step
If you already know the size you need, include it in your enquiry. If you are not sure, describe your product and we can discuss which range may suit it.