Let’s Make Jam!

I know, it’s been a while. So I’ll have to make it up to you with especially yummy recipes. Luckily, summer is upon us and with it a wonderful assortment of fruit and vegetables and long, sunny days to cook and eat them.

Today, we’ll learn to make jam. And, believe me, it’s simple. I did it this afternoon while answering some email. Here we go.

Apron-to-dish: approximately 2.5 hours; SoHo time: 45 minutes.

here’s what you will need for five 450g jars:

  • 2kg freshly picked, very ripe apricots, washed and pitted
  • 600g white sugar (300g per kilo of pitted fruit)
  • the juice of 2 lemons (1 lemon per kilo)
  • important: preserve-grade glass jars with (new) vacuum lids (ordinary jars may break, and recycled lids may not keep vacuum).

Superstition 1:Mother used to go on forever about how you should never stir jam, lest it will stick to the pot. Turns out this is one of the many superstitions that play such a fundamental role in passing recipes from one generation to the next. Like, you should not make preserves when the moon is rising. As it happens, jam will stick if you give it too much heat.

So, cooking the jam over a gentle heat is a very wise thing, as is stirring every 10 minutes.

Superstition 2: Mother also insisted that the mix of fruit and sugar should rest an entire night before being cooked. There is a reason to this: osmotic pressure will draw water (juice) outside the fruit and will give you a conductive fluid to allow the heat from the bottom of the pot to diffuse in the mix. In the old days, gauging the right amount of heat was very difficult, so this trick was probably devised to insure fruit didn’t burn (the juice kept the temperature around 100°C) before cooking. Of course, having put sugar in the mix means it will start to caramelise as soon as you fail to stir often enough.

So, the solution is to start cooking the fruit and the lemon juice, and add sugar later. Which is what I do.

Let’s go.

0-mile apricots --picked this morning
0-mile apricots –picked this morning

Get your apricots, wash them, pit them and cut them roughly (chunks give out juice faster than fruit halves or whole fruit). Put in a tall pot. Add lemon juice (it will give a lovely taste and also keep the jam lighter in colour). Do not add sugar.

First bring fruit to slow boil --no sugar!
First bring fruit to slow boil –no sugar!

Give a very gentle fire, stir every minute or two until it starts to boil slowly. Stirring brings juice out of the fruit, and juice allows fruit to cook rather than burn.

After about 20 minutes, you will have a very liquid, boiling mix. Boil for about an hour, stirring for a minute every 10 minutes (use an alarm clock). Remember: it must be a slow boil. Giving more heat will not speed up the cooking, it will only make the jam stick.

After 20 or so minutes of cooking, use an immersion mixer and mix the jam.

The (mixed) marmalade is almost ready
The (mixed) jam is almost ready

After an hour, the mix will start becoming viscous, that is less liquid. Add sugar now and stir vigorously until it is completely dissolved. Cook for 30 more minutes, always stirring for a minute every ten minutes.

Note on cooking temperature: it is imperative that, whatever time you keep the jam on the fire, the temperature of the mix never exceeds 110°C (230°F). At that temperature, fructose will start caramelising. This will affect the density as well as the taste of the jam. Is this a problem? It is. When put in the fridge after opening, jam with caramelised sugars will become extremely gooey to the point of not being spreadable. Usually this will not be an issue: if you keep the mix stirred, its temperature will remain nailed at 100°C until there is water left. But should you want to cook any further, make sure you have a cooking thermometer at hand, and to cook below 110°C.

Additional vacuum cooking for 30 minutes --no botulin here!
Additional vacuum cooking for 30 minutes –no botulin here!

Once you are happy with the viscosity of the mix, pour into jars, close the lids and place in another tall pot. Fill the pot with hot water until all lids are covered. Bring to a boil, and boil for at least 30 minutes. Turn out the flame and leave the jars in the water until cool. Thermal shock can break even preserve-grade glass. Plus, we’re almost done, why the haste? Go do something else for half an hour.

Once cooled, dry the jars and check that the lids are concave (they retain water poured on them, like a spoon): this means the jar is under vacuum and the jam can be safely stored for about a year —if home-made jam lasts that long in your household, that is.

What if a jar didn’t go vacuum? That’s just too bad, you will have to open it up and use it immediately. Usually, that doesn’t count like a great sacrifice.

Now is the time to behold the result of your work:

Don't you just love this colour?
I just love this colour

Apricot jam gives a particularly lovely shade of orange, doesn’t it? Two kilos of fruit yield approximately 5x450g jars, or 3x450g and 1x800g, as you see below.

The end product ready for use
The end product ready for use

Simona and I decided to have a quality test for dinner, lest our recipes gave awful results…

Gorgeous apricot colour (and taste)
Gorgeous apricot colour (and taste)

…believe us, it doesn’t.



  1. Great idea!!! I love apricots and will definitely try this. Thanks for the comment about the lids. Too many people look at the vacuum lid and think it is OK because it looks OK. But, they are only meant to be used once and tossed. I’m off to get some apricots.

  2. How delicious! I made it a few days ago and it was disastrous, almost unedible. I wish I had seen this post earlier.

    • Hi Francesca, by all means try again (this recipe works and apricot jam is just wonderful). And you can also tell your friends about us 😉
      All the best,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s