
Photo Mike Thomas
Cornish Native Oyster Grades
Large #0 (top) #1 (bottom) #2 (left) #3 (right)
Grading for size
Live oysters are usually graded into four sizes for sale in the UK, grade 1 being the largest; size is determined by measuring the length of the longest axis of the shell and its approximate weight.
Length and weight of the whole oyster are not necessarily directly related to quality as determined by the amount and appearance of the meat; variation with season and from ground to ground can sometimes result in a large shell containing a small amount of meat of poor appearance or a small shell comparatively well filled with firm meat. Selling price is usually determined within a species by assessment of size, yield and quality.
The native oyster is more highly prized than other species and in consequence generally commands a higher price.
http://www.fao.org/wairdocs/tan/x5954e/x5954e01.htm
Cornish Native Oysters – Mylor Oyster
Cornish Native Oysters – Mylor Oyster
Named after the harbour where the majority of the working boats are based. Large proportion and excellent cup. A high quality all rounder.
Grade 1 (approx. weight +100g)
Cornish Native Oysters – Silver Oyster
Named after the prestigious Silver Oyster Race - Perfect proportion and deep cup. Ideal for special occasions when appearance matters most!
Grade 2 (approx. weight 80-100g)
Cornish Native Oysters – Truro Oyster
Named after the Port of Truro Oyster Fishery that issues the licenses. Good proportion and cup.
Grade 3 (approx. weight 60-80g)
Cornish Native Oysters – Large Cooking Oyster
Great for Rockefella Oysters, see Online Shop for cooking instructions
Grade 1 (approx. weight 120-487g) The largest oyster we have landed so far was 487g and it was probably over 10 years old!

Photo: Mike Thomas
Brass Truro Corporation Oyster Gauge
The minimum size of oyster which is harvested is determined by the fishery byelaws (in 2007, only oysters which hang on a ring of 2 5/8th inch (equivalent to 66.3mm) diameter can be harvested and oysters which pass through the ring must be put over the side of the boat back onto the fishery). At this stage the fisherman makes a record of the date, catching area and quantity on the Live Shellfish Movement Document.












