Making marmalade from a small crop

We are in the middle of the marmalade fortnight, which is the two or three weeks in January and February when the bitter oranges come off and everything else stops. This is written for someone working with a domestic stove and a few kilos of fruit rather than a factory, because that is what we are doing too, just repeatedly.

The fruit

Bitter oranges, laranja amarga, which are not sweet oranges and are not a substitute for them. They are knobbly, thick skinned, full of pips, and inedible raw. They are also loaded with pectin and acid, which is exactly what a preserve needs and exactly what a sweet orange lacks. Marmalade made from sweet oranges needs added pectin and it will still be disappointing.

Use them within a week of picking. They do not keep, and the pectin is at its best while the fruit is just coloured rather than fully soft.

Two stage cooking, and why

The single most important thing, and the one that separates good marmalade from marmalade with leathery peel in it: soften the peel first, in water, with no sugar. Sugar sets the structure of the peel. Once it is in, whatever texture the peel has is the texture it will keep, and no amount of further boiling will soften it.

So: fruit halved, juiced, pips and membrane tied in muslin, peel shredded. Peel, juice, muslin bag and water into the pan, and simmer for around an hour and a half until a piece of peel squashes between your fingers with no resistance at all. Not almost. Completely. Then the sugar goes in, and from that point you are only working towards a set.

The muslin bag is where most of the pectin is. Squeeze it hard when you take it out, and you can see the pectin coming off it in threads.

Shred size

A medium shred, about two millimetres, is what we cut. Fine shred gives a marmalade that behaves like jelly and where the peel disappears. Thick cut gives you chunks that need longer in the first cook and that some people love and others find like eating bark.

Cut it by hand. A food processor tears the peel rather than slicing it and the pieces release differently. It takes about forty minutes to cut four kilos of peel and it is the meditative part of the day.

Setting point without guessing

Three tests, and use at least two of them.

Temperature. 104.5 degrees at sea level is the standard figure and it is reliable, provided your thermometer is accurate. Check it in boiling water first: it should read 100. Ours reads 98.5 and we have compensated for that for years.
The cold plate. Keep three saucers in the freezer. Take the pan off the heat, put a teaspoon on a cold saucer, wait thirty seconds, push it with a finger. If it wrinkles, it is set. If it floods back, keep going. Taking the pan off the heat for this is not optional, because thirty seconds of extra boiling while you decide is thirty seconds you cannot undo.
The flake. Lift a wooden spoon out and let the marmalade run off the edge. Early on it runs in a stream. At setting point the last of it hangs and comes off in a broad flake rather than a drip.

Overcooked marmalade is not tragic, it is just stiff and slightly caramelised. Undercooked marmalade is a syrup and there is nothing to do about it once it is in jars, so if you are unsure, another two minutes is the safer error.

Never double the batch

The temptation with a small crop is to do it all at once in a bigger pan. Do not. A marmalade batch works because of the ratio between the surface area of the pan and the volume in it, which is what governs how fast water evaporates. Double the volume in the same pan and you double the time it takes to reach setting point, and in that extra time the peel overcooks, the colour goes dark and the flavour flattens.

We use a wide pan and never more than about two kilos of prepared fruit at a time. Forty kilos of oranges is therefore something like twenty batches, over about ten days.

Potting

Jars washed and heated in the oven at 120 degrees, lids simmered in water. Fill hot marmalade into hot jars, right to about five millimetres from the top, lid on straight away and tight. The lid pulls down as it cools and you will hear it click. That click is the seal forming and it is the only evidence you need.

Wait ten minutes after the pan comes off the heat before you pot, and give it a stir. Marmalade that goes into the jar the instant it sets will have all the peel floating at the top of every jar. Those ten minutes let it thicken just enough to hold the shred in suspension.

How much we make

Six trees, somewhere between 35 and 45 kilos of fruit depending on the year, and about 230 jars of marmalade. That is the entire annual production and when it runs out, usually in the autumn, there is none until the following January. The same method is what people do on the preserving kitchen day in February, on the same stove.