Plum Jam

Plum Jam

(AKA 50 Plum Jam or 5-4-3 Jam)

Every year I wait for that brief window at the end of Summer when the plums come into their own. There are more than 200 varieties of plums, so choosing the right one for your jam is both a matter of preference and timing.   In late Summer, when the plums have had the best of the heat and a taste of Autumn rain they are at their sweetest and plumpest and, if you are not lucky enough to have a plum tree – they are also at their cheapest.
Choose unblemished, heavy plums with deeply coloured flesh.  Different variety of plums give vastly different flavours – my personal preference is for the tarter, deep ruby Santa Rosa plums that don't seem to suffer from the slightly sugary texture of the sweeter varieties.  For this jam I have used Ruby Red plums, which have a vibrant, luminous colour and a lovely borderline tart flavour.Plum Jam

What quantities to use?
Well, as I am a bit dim when it comes to mathematics, the easiest way I remember how to put together my plum jam each year is this – 50 plums, 4 citrus, 3kg sugar – 5-4-3 – easy!  Basically there will be some variation in the volume of plums, however I know that about 50 whole, un-stoned plums yields around 3kg of plum flesh.  I have used this recipe for Damsons, plums and apricots and the jam it produces is a soft, gentle jam which is how I prefer plum jam, without the sticky over-pectinised jam that is often found in pretty jars in posh supermarkets.

50 plums (or around about 3kg plums)
3kg sugar
2 oranges, juiced and skin peeled
2 lemons, juiced and skin peeled
2 tablespoons Cassis (blackcurrant) liqueur, plum brandy or Cointreau
¾  cup warm water

Prepare your preserving jars by washing them thoroughly and allowing them to dry upside down on the rack in a 70-90°C oven while you make your preserve.  The jars will be hot, but not scalding when removed from the oven.

Place whole plums, citrus zest and juice in a large preserving pan with ¾ cup of water over a low heat.
Allow the water to come up to a simmer and cook the plums down until the fruit is very soft and the liquid has been reduced by about two-thirds. Remove the pan from the heat and, using a slotted spoon, remove and discard the stones, skim any froth from the surface – alternatively if you have a large colander pour the jam into the colander and press the flesh of the plums through the holes.
Return the strained fruit to the saucepan, reduce the heat, add the sugar and stir until it has dissolved completely then bring the heat back up.

Bring the jam to a full rolling boil and boil rapidly for 15 minutes, then test for a set. If setting point has not been reached, boil for 5 minutes more, then test again. 
Once the jam is at the correct consistency, remove from the heat, stir in the liqueur and allow to stand for a few minutes before pouring the jam into your prepared jars. 

This jam develops flavour over time and is at its best after a week or two unopened in the pantry.  If you want to intensify the flavour, add a vanilla pod with the fruit.  Cinnamon, nutmeg and mace also add great flavour, and can be added (whole not grated) at the start with the fruit.