Cydonia oblonga Seeds | Quince
LATIN NAME: Cydonia oblonga
COMMON NAME: Quince
Plant Profile
Almost as important as the fruit is the rootstock. Selected quince clones, among them Quince A and Quince C, are the standard dwarfing rootstocks for pear, holding trees to a manageable size and bringing them into cropping early. The catch is compatibility: some pear cultivars graft cleanly and others reject the union years later, which is why a quince root is often worked with an interstock. Clonal propagation of these rootstocks is done by micropropagation from axillary shoots, with somatic embryos used where very large numbers of uniform plants are wanted.
For the firm paste eaten in Spain with sheep cheese, peel and quarter the fruit, simmer the pieces with an equal weight of sugar until the flesh collapses and darkens, then keep stirring over a low heat until a spoon drawn through the mass leaves a clean line. The pectin that makes raw quince so bracing is what sets the paste; the long cooking is what turns the pale flesh to a deep amber.
Science & Biotechnology
Quince’s pectin content is high enough that the fruit needs no added setting agent, and the flesh also carries procyanidins, chlorogenic acid and other caffeoylquinic acids, quercetin and kaempferol glycosides, all of which contribute the astringency that cooking softens. The scent is a separate chemistry: esters of decadienoic acid dominate the ripe fruit, which is why a single quince will perfume a whole room. The skin holds much of the aroma and most of the tannin, so peeling changes the character of the preserve.
Uses & Benefits
Culinary use is almost entirely about transformation. Quince jelly is made from the strained juice of the peeled fruit, quince paste from the pulp cooked down with an equal weight of sugar until it can be cut into slices and eaten with cheese, and quince butter from a slower, softer cook. In Portugal and Spain the paste is a standard accompaniment, and in the eastern Mediterranean the fruit is stewed with lamb or used to flavour brandy. Quince jelly needs nothing but fruit, sugar and a little water, and the set is firm enough to turn out of a mould. Seed mucilage has a long history in cosmetics and pharmacy as a demulcent and a fixative for hair.
Growing from Seed
The mucilage sits in the outer cell layers of the seed coat and expands many times its own volume when wetted, holding the seed in a slippery envelope that helps it survive a soak. Chemically it is an acidic polysaccharide built largely of glucuronic acid with xylose, arabinose and galactose residues, and it is extracted simply by steeping the seed in cold water and straining. Treated as a hydrocolloid it is a stabiliser and thickener; used on the skin it dries to a firm, faintly perfumed film. The kernel itself contains cyanogenic glycosides, so the mucilage is used rather than the crushed seed.
The pale yellow flesh is gritty because it is packed with brachysclereids, thick-walled stone cells clustered around the core and scattered through the pulp. They are the reason quince is never eaten raw with pleasure, and the reason the fruit must be cooked, sieved or milled. Around them the flesh is dry at first and then, on cooking, releases the pectin that sets the fruit into a firm, sliceable paste once sugar is added.
Scoop the seed from ripe fruit, rub it in sand under running water to strip the mucilage, and sow at once or store it cool and damp. Sow in a deep pan or open bed in autumn, covering each seed to about twice its own thickness with a mix of loam, leaf mould and grit, and let winter do the work. The seed coat is hard and slow, so patience in a cold frame is normal. Flowering and fruiting in the open garden need a warm, sheltered site, since the flowers open early and the fruit needs a long season to ripen. Quince is largely self-fertile but crops better with another variety planted nearby, and the fruit is picked once it has coloured and before it softens at the stem end.
Lift the seedlings when each has two true leaves and line them out in a nursery bed at thirty centimetres apart, or pot them into deep containers if they are to be grown on for budding. Water steadily through the first summer, keep the rows clean, and watch for the rust that alternates with juniper, which shows as bright orange spots on the leaf. Fire blight is the other serious trouble, so prune out blackened shoots well below the damage and disinfect the tools.
Our Take
Plant a quince for the smell alone and you will keep it for the jelly. Give it sun, a deep soil and shelter from early frost, then leave the fruit on the tree until it turns fully gold. Anyone building a collection of old orchard fruits should look at Pseudocydonia sinensis, Chaenomeles sinensis, Japanese quince and medlar, which cover the same ground in different seasons.
Related Reading
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