Tough marmalade peel

Sugar stops the clock

Citrus peel softens in water as heat breaks down the pectin and cellulose holding it rigid. That happens steadily during the first, sugarless simmer.

Once sugar goes in, the syrup around the peel becomes concentrated and draws water out of it by osmosis. The peel firms rather than softening and it stays exactly as tough as it was at that moment.

So the whole question is whether the peel was soft enough before the sugar. There is no later opportunity, which is why the first stage of a marmalade takes so much longer than people expect.

Getting the peel soft

1. Simmer the peel and juice in water, uncovered, with the pips and pith tied in muslin.
2. Give it far longer than seems reasonable. Two hours is normal for thick Seville peel and is not excessive.
3. Test properly: lift out a piece and squash it between finger and thumb. It should collapse with almost no pressure.
4. If it still has any resistance at all, keep simmering. Test again in twenty minutes.
5. Do not judge by appearance. Peel looks translucent and cooked long before it is soft.
6. Only when it squashes easily should the sugar go in.
7. Top up with water if the level drops below the peel during the long simmer.

Things that make it worse

Cutting the peel too thick

Thick-cut marmalade needs considerably longer than fine shred.

Hard water

Slows softening. A pinch of bicarbonate of soda in the simmering water helps, and too much makes the peel slimy.

Not enough water

Peel above the waterline does not soften.

A lid on

Traps steam and slows evaporation, which is not the problem — but it also means the level does not drop and cooks are tempted to stop early.

Old or very thick-skinned fruit

Takes longer. Sevilles have thick peel by nature.

Adding sugar because the clock said so

The single cause behind almost every tough marmalade.

If it is already in the jar

• It cannot be softened by reboiling. Sugar is present and the peel will stay as it is.
• Chop it smaller. Tip the marmalade into a bowl, cut the peel down with scissors, and repot. Small chewy pieces are far less intrusive than long strips.
• Blitz it briefly for a marmalade with no distinguishable peel, which some people prefer anyway.
• Use it in cooking rather than on toast — a glaze for ham or duck, stirred into a bread and butter pudding, or in a marmalade cake.
• In a sauce, warmed with soy, ginger and chilli, where the peel softens in the liquid over time.
• Accept it. Thick-cut marmalade is meant to be chewy; the fault is only a fault if it is genuinely tough.

Common questions