Sunday, 8 September 2013

Nunhead Blackberry Jam

Last summer I made my first attempt at jam making. I was at home in Gloucestershire during strawberry season so headed to Over Farm Market and picked a mountain of delicious juicy strawberries. The jam was a big hit and the jars i handed out to my friends and family did not last long, which was a good thing because the couple of jars I left in the cupboard got mouldy after a few weeks. The jam was also runnier than i would have liked.

This year I spent most of the summer in London, I was keen to try my hand at another batch of jam but didn't want to spend a fortune on punnets of fruit from supermarkets.
The one berry i knew i could find in abundance, and for free, a few minutes walk from my house, were blackberries.
On the other side of Peckham Rye there is a huge over grown cemetery in Nunhead. In amongst the neglected graves and shady trees, at this time of year, there are mountains of ripe blackberries.

I headed to the cemetery armed with a big 4L tupperware and a couple of hours later returned home with well over a kilo of fruit and a few stings and scratches to show for my afternoons foraging.

I reserved some of the riper berries for eating and pie making and used most of them for the jam.
Below is a rough guide to how a i went about making the jam. I looked at a few recipes online and found some useful tips in the Preserves River Cottage Handbook. 

If i was to make the jam again i think i would use a bit less sugar and perhaps a mix of normal sugar and jam sugar. I don't think i needed quite the amount of pectin that i added (by using all jam sugar which comes with pectin in it).

The quantities below filled about 5 standard size (400g) jam jars

1kg blackberries (not too squishy and ripe)
1.25 kg jam sugar
100ml lemon juice (3 small lemons)

Before setting out fruit picking I dug out some empty jam jars and soaked them in a sink of hot soapy water until the labels came off.
I rinsed and drained them and on my return put them in the oven (along with the lids) at 100C while I made the jam.

I gently washed the blackberries removing any twigs and spiders and then dried them by tipping them out onto kitchen towel.

Before starting to make the jam I put a few saucers in the freezer to get cold as them come in handy when checking that the jam is ready, very useful if you don't have a jam thermometer.

I got out Ceri's huge chutney making pan (make sure you have plenty of room as the jam will bubble up) and chucked in 200-300g of the blackberries with the same amount of sugar. I then crushed the berries with a potato masher.
The pan was then heated gently and once the mixture was warm I added the rest of the berries and brought the jam up to simmering point, stirring with a wooden spoon to stop the fruit sticking to the bottom of the pan. After 5 minutes of simmering I added the remaining jam sugar.

You then need to stir the jam until the sugar has dissolved, this took longer than i expected, about 10 minutes of heating and stirring, checking the back of the spoon for sugar granules.
Once the sugar had dissolved i added the lemon juice and increased the heat until the mixture boiled.

The jam bubbled up the sides of the pan, i let it boil for about 10 minutes without stirring.
I then tested the setting point by dripping a little of the jam onto one of the cold saucers which i had put in the freezer. If you poke the blob of jam on the saucer with you fingertip, if it has set the surface will wrinkle, you can then be confident your jam is ready.

I removed the jam from the heat, gave it a quick stir and took the sterilized jam jars out of the oven.
I then decanted the jam into the jars while it was still hot. I placed a circle of grease proof paper on the top of each full jar before screwing on the lids.

Once the jars had cooled i made sure the lids were tight and then they were ready for labeling and storing in the cupboard ready to be eaten.
Given the amount of sugar i added i am confident my blackberry jam will last a lot longer than last years effort!



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