Strawberry jam. (Pam Corbin.)

Strawberry jam

Based on a recipe from River Cottage Handbook No.2: Preserves by Pam Corbin
Makes 6 medium jars (about 1.6kg of jam)

1kg strawberries, stalks removed and large ones halved or quartered
500g granulated sugar (or a mix of sugars: I used half soft brown and half granulated)
450g jam sugar (sugar with pectin in it)
150ml lemon juice (which worked out to be three large lemons' worth)

You will also need:
A maslin pan, or similar high-sided heavy duty pan.  It has to be really big to allow for the jam to boil up to at least double its own depth
A sugar thermometer or electronic meat thermometer: I used to use the big glass type, and after two broke, I now use my electronic meat thermometer
6 or 7 washed, dried and sterilised jars and lids (I always prepare more jars than I think I'll need, just in case)
A jam funnel is very handy and prevents too much jam getting on the worktop
A small ladle for transferring jam to jar
A few wet cloths on hand for spills
Sticky labels

1. Before you start on the jam wash and sterilise your jars in either a low oven or the dishwasher.
Wash the lids and/or kilner jar rings.

2. With all of the above kit to hand, get going with the jam.
Use a potato mash to squish down 200g of fruit with 200g granulated sugar in the jam pan.  
Slowly bring the squished fruit to a simmer and stir around a bit to dissolve the sugar.

3. Add the rest of the fruit and carry on simmering gently until the fruit soften.  
This should take about 5 minutes, maybe a bit longer.

4. Add the sugars to the warm fruit and stir slowly, enough to encourage the sugar to dissolve but not so much as to break up the fruit.  
Reminisce about who used to make jam in your house and immerse yourself in the smell of your childhood.

5.  When the sugar has dissolved, add the lemon juice, being careful not to drop in any pips, but don't worry too much about lemon flesh.  
As an aside, having forgotten to buy lemons when I got the strawbs I toyed with the idea of using bottled lemon juice for the recipe, and then swiftly told myself off for contemplating such a thing.  
But I suspect that it would have been Jif lemon that would have made it into the Inverness vintage back in the 80s so I'm not convinced I would have ruined the jam had I given in to my slovenly instincts.  
But I went back out and bought lemons, just in case.

6. Increase the heat under the pan, and let the jam come up to a full rolling boil.  
This is where a massive pan is essential or else you'll have boiling jam all over your cooker.  
If I remember correctly, my Gran made hers in the pressure cooker pan (no lid, obviously) which was a brilliantly heavy gauge steel and perfect for jam.  
I now have a maslin pan (thanks Mum!), but my stock pot has also been put to use for preserves before.  
It just has to be deep enough to allow the jam to bubble up as much as twice its depth.  
If you look closely in the photos, my jam was originally sitting at 1.6l mark, and bubbled up to just under  the 5l line.

7. Let the jam boil for about 10 minutes.

Then comes the science bit.  
Setting point is an elusive stage around which much cooking lore has been written.  
Tales of cold saucers, jam "flaking" off wooden spoons and skins forming all confuse me and I never seem to get them right.
I think my marmalades have set in the past because I pretty much boiled all hell out of them, almost to the point of burning (but I do love the burnt sugar taste that imparts).  
If you don't have a sugar or electronic thermometer, I'm going to back away at this point and tell you to buy Pam's book, or find another resource that'll go into the mysteries of setting points.  
However, if you do have a thermometer then we're back in business.

Once the jam has boiled in its lava-like guise for a good 10 minutes, check the temperature.
If it's already at 104.5°C then you're there.  
If not, let it continue to cook until it gets to that point, and then take it off the heat.

8. At this point your jam probably has a mass of pink foamy scum on it.  
I like the scum, and its this that my granny skimmed off and let me eat.  
Some gentle stirring usually disperses these bubbles (for that is what they are: its not scum like stock scum, it's just air bubbles from the vigorous boiling).  
You can - and I do - drop a little bit of butter into the pan to help this disperse.  
No idea why this works, probably something to do with fat rupturing the air bubble surface or something.
Or you can skim it off, or you can leave it.  
Choice is yours (but it does taste rather good on a bit of bread.  
Cook's treat).

9.  Now is the time for the jars.  
However you've sterilised them, they should be warm as this point.  
Decant the hot jam into the pots, filling them almost to the top and seal immediately.
Have some damp cloths to hand to minimise the drama of hot jam running over the tops of jars/into your cooker/down the worktop.  
If you are left with not-quite-a-jar's-worth at the end, either put it in a jar anyway, but use it first, or keep it in a bowl in the fridge and eat in the next couple of days.

Leave your jars to cool then label them up with what's inside and when you made it.