CARRAGHEEN, IRISH MOSS, PEARL MOSS

a species of edible seaweed named after the town of Carragheen, near Waterford, Ireland, found on the coasts of the British Islands, the rocky shores of continental Europe and the Eastern shores of the Northern United States and Canada. Similar varieties abound also on other parts of the American coast line.

The Carragheen of domestic use is obtained principally from New Hampshire and Massachusetts, the harvest season there extending from May to September. After gathering, the plants are washed in salt water and spread on the beach to dry and bleach, the process being repeated several times.

As marketed, Carragheen is in pieces of from two to three inches to a foot in length, cartilaginous and flexible in texture, branching in shape, and in color from a reddish brown to straw color or white, varying with local differences in the plant and the extent of the bleaching.

The greater part of the supply is employed in the clarifying of beer. The remainder is retailed through druggists and grocers, etc., the best qualities packed in half pound and pound boxes.

To make a nutritious beverage, which is considered also a good demulcent for coughs, a scant ounce of Carragheen is placed in a quart to three pints of water, gently heated until the liquid is syrupy in consistence and then strained, milk and sugar or sugar and lemon juice being added to taste.

In the preparation of blanc-mange or jelly, a larger quantity is required. A good receipt is to soak a small cupful in cold water for about five minutes, then tie it in a cheese-cloth bag, place in a double-boiler with a quart of milk, add a little salt and cook for a half hour. When done, take the bag out, flavor the liquid with lemon or vanilla extract and pour into a mold or small cups, previously wet with cold water. When the jelly is set, it can be eaten with sugar and cream or fruit as desired.

For the Modern Kitchen

The entry is half reference note, half recipe: two usable preparations sit at the end of it, a thin drinking decoction and a milk blancmange set with nothing but the seaweed itself. Both depend on the same principle, that carrageen releases its gelling polysaccharides slowly into hot liquid and sets only on cooling.

Rinse before you soakDried Irish moss carries sand, shell fragments and small shrimp no matter how carefully it was beach-dried. Rinse it in several changes of cold water until the water runs clear, then soak; the five minutes given is a minimum, and ten to fifteen does no harm.
The quantities are generousA "small cupful" of dried moss to a quart of milk is more than modern practice, which runs closer to a half ounce per quart; dried moss is very bulky, so weigh it rather than measure it by volume. Gel strength varies with species, season and how hard the moss was bleached, so chill a teaspoon of the strained liquid on a cold saucer to judge the set before you fill the moulds.
A scant ounceFor the beverage, a scant ounce is just under 28 g of dried moss, which is a surprisingly large loose volume, near two cups. Reduced into a quart to three pints of water it gives a thin, faintly marine syrup, not a jelly.
Double boiler, and whyThe milk is cooked over water rather than direct heat for a full half hour to avoid scorching, and this matters more than it sounds: scalded milk solids stick and give the finished blancmange a burnt undertone that no flavouring covers. Keep the water below a rolling boil.
Squeeze the bagThe cheesecloth bag is the whole method, and a good deal of the extract stays in the swollen weed rather than in the surrounding milk. Press the hot bag firmly against the side of the pan with a spoon before discarding it, or strain the milk through fresh cheesecloth if you soaked the moss loose.
Setting timeCarrageen usually sets softer and more quaveringly than gelatine, and it needs cold, not just time. Four hours in the refrigerator is realistic for individual cups, six or more for a single large mould; at these proportions it is unlikely to reach the firmness of a modern packet jelly.
Flavour it after cookingVanilla and lemon extracts are alcohol-based and lose their top notes over a half hour of heat, so adding them at the end, as the entry directs, is sensible. Lemon juice, by contrast, belongs only in the water-based drink; acid in hot milk risks curdling it.
YieldA quart of milk is eight half-cup moulds before losses; allowing for what the bag holds back, expect six or so, or four generous ones. Wetting the moulds with cold water, as directed, is what lets the set jelly slide out.
What to buyLook for whole dried Chondrus crispus sold as Irish moss or carrageen, from a seaweed supplier or health food shop. This is not the same as powdered carrageenan, a refined extract that behaves quite differently and is dosed by fractions of a percent.

A Little History

Carrageen was a commercially significant wild seaweed in the Anglo-American kitchen, and this entry catches it at the point where the grocery trade had already been overtaken by the brewery: most of the crop, as the writer says, went to clarifying beer, where Irish moss finings drop protein haze out of the boil and are still used by homebrewers under that name. The name is generally traced to the Irish carraigín, "little rock", after the stones the weed grips; the claim here that it comes from a town called Carragheen near Waterford is the older, traditional explanation and appears in a good many nineteenth-century references. The American supply came from a genuinely local industry on the New England shore, particularly around Scituate on the Massachusetts coast, where mossers raked the weed from dories and bleached it in the sun on the beach exactly as described. Its double life as food and medicine is the reason it turned up at the druggist as often as the grocer: a thin carrageen decoction is a demulcent, coating an irritated throat, and the milk blancmange was standard invalid and convalescent cookery in a period when soft, bland, slightly nourishing dishes were a recognised category of household food.