About this recipe:OK so I've been looking for a recipe for a simple jam, blackberry glut going on here, well, popped out Sunday afternoon for 2 hours came back with 4kg of juicy ripe loveliness! To say I've researched would be an understatement (trawled all the foodie sites including here and all my recipe books, to little avail). Found many lovely sounding recipes so decided to take the plunge, picked up pears on sale and rhubarb so forgot the cooking apples, but hey ho. Necessity is the father of invention or something along those lines!
Prepare your fruit. I used 500g rhubarb, 700g pears, and 550g blackberries. Cut rhubarb into 1cm pieces, peel pears and remove stalk and bottom, and any 'stringy' core. Chop into 1cm chunks and cover in lemon juice. Pick over blackberries and rinse under cold water, drain well.
Place all fruit into large heavy bottomed pan and use potato masher to release some of the juices.
Gently simmer until fruit soft, but still has some structure, and avoid stirring too often. Took me about 30 to 35 minutes.
Place in preserving pan at this stage, add warmed sugar and heat slowly until all sugar is dissolved, stirring only occasionally.
Add knob of unsalted butter and bring to a rolling boil. Boil rapidly for at least 3 to 4 minutes, or until reaches 104 degrees C on your thermometer.
Remove from the heat and stir in pectin, skim if necessary - I didn't need to as stirring in the pectin appeared to clear any scum. Next time I will use all the pectin (250ml) as it is a very soft jam, but very tasty!
Allow to cool slightly - apparently this stops the fruit 'floating', then pot and cover in the usual way. Leave to cool before storing in a cool, dark place.
I had no usual way of sterilizing jars, so had used hot soapy water to re-wash the jars and lids and very hot water to rinse all washing water off, then put them on a tray in the oven for 15 minutes at 150 C / Gas 2 to finish drying. I let my jars cool very slightly so I was able to handle them with an oven pad while filling and putting lids on. I found that the smaller square/hexagonal jars are easier to make sure the lids are secure as the round ones were 'less' cooperative. The taste - WOW was what my son said, LUSH! And that was when it was time to clean the pan, hope it sets okay too!