Potted shrimps, old fashioned and buttery, are forever connected with Morecambe Bay in Lancashire, where shrimps are potted to this day. The main season for them is from the August Bank Holiday (the last Monday in August) to Christmas. It is the peeling that makes potting shrimps so labour-intensive. In Morecambe Bay, the hub of the potted shrimp industry, they declare that a good peeler gets through about 700g (1lb) an hour and the industry will not die until the last of the old-time peelers hangs up her apron.
There are two types of shrimps - grey shrimps which turn pink when you cook them, and brown shrimps which turn browner when boiled. It is no surprise that people from Morecambe Bay rate the brown ones best - they soak up more butter and they are the type caught around Ulverston and Flookburgh in the Bay. In the past, horse and carts were used to catch the shrimps but nowadays tractors are used to haul the nets ashore. It is a dangerous job - the tractors can sink in the sands and the tide rises so fast that it can cut you off from the shore - so you need to know the terrain.
There are about ten tractors working the sands nowadays and about the same number of shrimping boats, called nobbies, further up the Bay. Once the tractors have brought the brown ships ashore, they are boiled in seawater and quickly cooled for peeling and potting.
There are some shrimp boats off the East Anglian coast and shrimps used to be caught in the Thames estuary, but shrimping has been a speciality of Morecambe Bay since 1799, when Baxters set up the first factory for processing them. The introduction of the railways opened up new markets in the nineteenth century when shrimps became a fashionable teatime treat, often eaten in sandwiches.
The tiny brown shrimps are the most authentic to use and certainly the most delicious for this recipe. Unfortunately, they are not common in supermarkets, so you may have to order them from a good fishmonger. If you are not keen on spending the time peeling them then small peeled pink prawns can be used instead.