Recent thoughts concerning the quince, being the original fruit that eventually led to our orange marmalade, meant that, when the Seville oranges appeared in the stores, I simply had to buy some for homemade marmalade. Marmalades can be made with all sorts of fruits, especially various citrus. The classic British version, though, has to be made with the bitter Seville oranges. These are in season for just a short time around January to February. Although a veteran preserver of various jams, chutneys, and pickles, I had never before made marmalade, although I was broadly familiar with the method. The first task, then, was some research.
Jams are fairly straightforward – equal parts by weight of fruit and sugar, brought to a boil until a set is achieved. That will suffice for many fruits, but some need a little extra attention as they are low in pectin. Strawberries are one example, where a better set can be achieved by including a small amount of some other fruit that is high in pectin, such as gooseberries, using a jam sugar that includes pectin, or adding pectin or a homemade ‘pectin stock’. Though jam recipes are similar, I was a little surprised by how much variation I found in those for marmalade, which were not at all consistent in either method or quantities.
Methods seem to vary along three different themes. One approach involves boiling the whole oranges until soft and then processing them. Another involves processing the oranges first, squeezing the juice and retaining flesh and pips for their pectin. The third variant involves soaking the pips and flesh overnight to extract the pectin. Quantities vary, with the basic rule being twice the amount of sugar, by weight, to oranges. However, half a dozen recipes found online had anything from 1.5 times sugar to fruit to a whopping 4 times. The amount of water added also varied widely. Most recipes include the juice of one or two lemons.
This was not at all encouraging. Rather than copy any one recipe, I decided to adopt what I thought to be a fairly simple method, used the most common 2 to 1 proportions and made something of a guess on the quantity of water. My starting point was the 1.2kg of Seville oranges that I bought, which meant 2.4kg of sugar. For the water, I took a guess at 3 litres. Although this worked fine, it did need quite a long time to boil to reach the setting point, so in the recipe below, I suggest 2.75 litres instead.
Like jams and jellies, achieving a good set with the marmalade depends on various complicated chemical things going on that relate to the amount of acid, pectin, and sugar, and the temperature the mixture reaches. If one uses a sugar thermometer, a set is typically reached at 105°C. The usual test is to place a little on a chilled saucer and leave for a few minutes. It is set if the surface wrinkles when one slides a finger through it. Even if using the thermometer as a guide, I still like to check on a saucer. Citrus contain lots of pectin, but even so, some recipes call for the pips and flesh to be soaked overnight to extract as much pectin as possible to ensure a set. I am not nearly so obsessed by a good set – a somewhat soft set is, to my mind, preferable to a hard jelly like result. Nonetheless, I have noted a point in the recipe at which one could, if time allows, leave the orange trimmings to soak. Otherwise, in this recipe, I merely boil the trimmings for a while.
For my first attempt at marmalade, I was very happy with the results. It has a fine amber colour, a strong bitter orange flavour with a suitable balance of sweetness, and a quite reasonable, but not too solid, set. For two jars I stirred in a splash of rum before bottling, which works very well with the oranges.