There are a number of grading systems in use throughout the world for Tuber melanosporum (and other truffle species). At Kings Truffles we have tried to keep things simple and have adopted a system that is in line with others in use in Australia and New Zealand both for domestic and export markets.
A grade – Premium and Iconic Truffles
As the name suggests these should be top quality. The aroma should be pungent with the characteristic colour and taste of the species. They should be mainly regular in shape with little or no damage to the peridium (outer protective layer or skin). Weight for premium truffles is between 30 and 300grams. Any over 300grams are termed iconic, as they are viewed by customers as such.
– Perfect for shaving onto dishes at the table for a bit of glitz and glamour
B Grade – Small or Broken Truffles
These are the same as A grade with regards to flavour, aroma and colour but are smaller, between 15 and 30grams. There may be slight damage from harvest or predators as well as shape imperfections. They can be whole, broken or large off-cuts and trimmed lobes.
– Can still use at the table but also used for infusing and dish preparation
C Grade – Slices and Bits and very small Truffle
Still using every bit of the ripe truffle, C grade comprises of slices (necessary to expose the characteristics of the gleba, the inside flesh of the truffle, for A and B grade truffles) and bits smaller than 15grams, that have either been broken or cut from a larger ripe truffle. It also includes whole truffles less than 15grams. Still containing a pungent truffle aroma but can be slightly less in intensity compared to A and B grade.
– Fantastic in butters, sauces and preparation of pasta/rice dishes
All grades minimum requirements:
- Truffles are Perigord black truffle (Tuber melanosporum) harvested in New Zealand and to be supplied fresh within a few days of harvest (unless stated otherwise).
- Free from and major physical damage such as rotting and decay, frost damage and pests or damage caused by pests
- Aroma must be well developed and truffle sufficiently developed for the specific grade. A small slice can be taken to reveal the gleba (inside flesh of truffle) that should be black with white veins if properly ripened while the peridium should be a dark brown/black colour
- Free from any visible dirt and foreign matters
Over ripe and rotten truffles are still used by Kings Truffles, either to put back onto the soil around the base of the trees at the end of the season, or to use for innoculum when infecting tree seedlings. The rot does not impair the quality of spore germination but actually often has a higher mature spore count.