Marmalade

The most common reason is not reaching 220°F (104°C). Always use a reliable thermometer and boil until you hit that temperature. If you boiled to temperature but it still didn't set, the batch lacked sufficient pectin—next time, include extra lemon juice or a tablespoon of powdered pectin dissolved in a little water.

Regular sweet oranges will make a less traditional marmalade because they lack the bitterness and tartness that make Seville marmalade distinctive. If you cannot find Seville oranges, use a mix of regular oranges and extra lemon juice, or look for Seville oranges in winter (January–March) when they are in season.

Unopened jars of properly set marmalade will keep in a cool, dark cupboard for up to 1 year. Once opened, refrigerate and use within 3 to 4 weeks.

You can scale this recipe, but the cooking time and final yield may vary. Do not halve it below 1.5 lbs of oranges, as the batch may not reach setting temperature properly. Always use a thermometer and do not guess on setting point when scaling.

Marmalade is best served with buttered toast at breakfast, on croissants, or stirred into Greek yogurt. It also pairs beautifully with cheese boards (especially sharp cheeses), and is traditionally used as a glaze for ham and duck.

Seville oranges are naturally bitter, but if it tastes unpleasantly bitter, you may have included too much white pith with the peel. If it's too sweet, next time reduce the sugar slightly (3.5 lbs instead of 4 lbs), but do not go below 3.5 lbs or the marmalade may not set.