The larger, more expensive dried ones can have better taste than the small ones.
They will be a pinkish-orange, though some will have their colour artificially enhanced.
To make them, shrimp are boiled with their heads still on in salted water, then dried either in the sun, or more likely these days, in forced-air drying machines for 6 to 7 hours. The heads and shells are then removed through a mechanical process, though they can also be bought shell on.
They are sold in small plastic bags either whole, or ground to a powder. Some bags will be quite whiffy, others will have almost no smell.
Choose ones that are bright coloured (either pink or orangey); as they get old, they will turn brown and harden. Don’t buy them if they are rock hard.
When using whole ones, soften in warm water for 1/2 hour before use. The soaking water can be used in cooking.
The flavour mellows during cooking.
You can grind your own at home with a spice grinder to be used as a spice.
4 oz (115 g) = 400 small dried shrimp.
Store indefinitely in a sealed container in a cool, dark place (no need to refrigerate.)
Discard if in storage whole ones eventually start to disintegrate.