Strawberry Jelly

A cross-reference recipe: it assumes you have the Currant Jelly method in front of you and only tells you what changes. The currants are not for flavour but for chemistry.

• Why the currants are thereStrawberries are low in both pectin and acid and will not set on their own. The quart of red currants supplies both, which is the whole reason for the ratio. Skip them and you get syrup.
• The method it points back toCurrant jelly conventionally means: crush the fruit, heat gently until the juice runs freely, drain through a scalded jelly bag without squeezing, then measure the juice and boil it with sugar. Squeezing the bag tends to give a cloudy jelly.
• Sugar, which the recipe does not stateThe omitted proportion is most likely the usual one for currant jelly: roughly a pound of sugar, or about a pint measure, to each pint of strained juice. Modern practice often drops to three-quarters, which sets slightly softer.
• Quantities in modern termsFive quarts of berries is roughly 6.5 to 7.5 lb; a quart of currants somewhere around 1.25 lb. Expect perhaps 3 to 4 pints of strained juice from a drip bag.
• Fifteen minutes is a guide, not a ruleCurrant juice will often sheet off the spoon well inside the quarter hour; the extra time here allows for the weaker strawberry juice. Judge by the sheet test or a thermometer reading 220F at sea level rather than the clock, since the evaporation rate depends largely on the width of your pan.
• Finding currantsRed currants disappeared from much of American gardening after the early-century bans tied to white pine blister rust, and are still uncommon in supermarkets. Frozen ones work as well as fresh here.
• SealingThe book's era sealed jelly under a poured paraffin cap, which is no longer recommended because the wax shrinks and admits mould. Fill hot into sterilised jars and process in a boiling water bath according to current guidance, or refrigerate and use within a month.