Crab apple

Malus sylvestris

Thirty-degree isometric board, 5 mm grid, 30° hatching, 10 cm scale bar. Rotation: Hedge row Z — take from the outside of each tree, leave the crown.

The crab apple is the plant that makes other preserves possible. It is far too sour to eat, and that is the point: the same malic acid and the same very high pectin that make it inedible raw are what allow a low-pectin fruit — rowan, sloe, elderberry, blackberry — to set into a jelly. A crab apple in the pan is the difference between a jelly and a syrup.

Fruit

September – November, when the fruit comes away with the stalk

Fruit

chilled 42 days

Fruit twists off with a short stalk; skin firm with no bruise or moth exit hole.

1 Salt-brine pickling — in 3 % brine, 21 days
1 L wide-mouth jar, glass weight, 3 cm headspace
2 Drying — rings at 55 °C, 10 h
Mesh tray in a single loose layer ≤ 2 cm deep, 1–2 m/s airflow
3 Lactic fermentation — 3 % sugar, 14 days
1 L wide-mouth jar, smaller jar as weight, 2 cm headspace, plate underneath
4 Oil and vinegar infusion — in vinegar with a mother, 6 weeks
Dark narrow-neck bottle; candy thermometer for the 60 °C ceiling
5 Candying and sugar preservation — jelly 450 g sugar : 600 mL juice
Jam thermometer to 110 °C, wire rack over a tray for 24–48 h of drying

Operation	Parameter · duration
Harvest cue	Fruit twists off with a short stalk; skin firm with no bruise or moth exit hole.
Blanch	not required — used raw
De-bitter	None; the acid is the product. Never crush the pips.
Chilled	42 days

Part

Blanching

Salt-brine pickling

Drying

Lactic fermentation

Oil and vinegar infusion

Candying and sugar preservation

Fruit

skip

in 3 % brine, 21 days

rings at 55 °C, 10 h

3 % sugar, 14 days

in vinegar with a mother, 6 weeks

jelly 450 g sugar : 600 mL juice

Wild or feral, which matters less than you think

A true wild crab apple has small fruit, 2–4 cm across, with a short stalk and a bitter, astringent flesh. Feral orchard apples that have gone back to the hedgerow have larger fruit and a milder taste, and hybrids are in between. Telling them apart is a job for a botanist looking at leaf hair and fruit pips.

For the kitchen, the useful distinction is different: taste the fruit. A crab that is mouth-puckeringly sour and slightly astringent is ideal for jelly. One that is mild enough to eat is better used in a chutney or baked whole. Anything with a soft, brown or maggoty core goes in the compost.

Picking is straightforward: the fruit should come away with a twist and a short piece of stalk. Windfalls are usable but check each one for bruising and for the small exit hole of the codling moth larva. Crab apples keep for six weeks in a cool, dark, dry place and much longer if you wrap them.

The jelly, and how to use it as a base

Wash and roughly chop 1 kg of crab apples without peeling or coring — the pectin and the acid are in the skin and core. Simmer with 800 mL of water for 40 minutes until the fruit is collapsing, then strain through a jelly bag overnight and do not press. Use 450 g of sugar per 600 mL of juice and boil hard until it reaches 105 °C.

That is the base. Everything else is built on it: add 300 g of rowan berries or sloes or blackberries to the pan at the simmering stage for a flavoured jelly; add 2 g of dried chilli and 5 g of grated ginger for a hot one that works on cheese; add rosemary, thyme or bay for a herb jelly to go with lamb.

The one technical note that matters is the sugar ratio. Measuring the juice rather than the fruit is what makes the set reliable, because crab apples vary enormously in how much water they give up. A jelly made from a fixed fruit-to-sugar ratio works about three times out of four; one made from measured juice works every time.

Beyond jelly: verjuice, vinegar and the bottling of a whole crab

Verjuice is the old English answer to lemon juice: the unfermented pressed juice of sour apples, used to sharpen sauces before citrus was affordable. Make it by chopping 1 kg of crabs, simmering with 500 mL of water for 20 minutes, straining and bottling. It keeps three months refrigerated and is excellent in a dressing, in a white sauce or as a deglazing liquid for pork.

Crab apple vinegar is the same process continued: take the strained juice, add 100 mL of raw cider vinegar as a starter, and leave in a wide jar covered with cloth for four to six weeks. It grows a mother, it goes slowly, and the result is a soft, fruity vinegar that is better than most shop-bought cider vinegar.

Whole crabs are also worth bottling in syrup, which is the one way to eat them directly. Core them, pack into jars with 60 % syrup and a clove per jar, and process in a water bath for 20 minutes. They come out as a sharp, soft fruit that is good with cold pork, and they keep a year.

Identification note: Crab apples are edible but very sour and mildly astringent; the seeds contain cyanogenic glycosides like all apple pips, so do not crush or blend whole fruit. Cooked and strained, they carry none of it.