Homemade strawberry jam
The red of June sealed in a jar. Sugar, fruit, and a little patience at the stove, the simplest technique for a moment to last almost a year.
The jam technique rests on a simple principle: sugar, in a concentration above 55%, captures the free water and blocks any microbial growth. The fruit's natural pectin (or added, for fruits that lack it, like strawberry) gives it its consistency. It is the most universal preserve in Europe. Learning to make your jams is learning to watch a simmer, to recognise a coating on a spoon, to trust a know-how spoken in the gesture more than in the thermometer.
Ingredients
- Fresh strawberries (Gariguette, Mara des bois, ciflorette)1 kg
healthy fruit, just ripe (not mushy), it is at this stage that pectin is most present
- Special jam sugar (with added pectin)800 g
strawberry is naturally low in pectin, so gelling sugar is simpler. Otherwise: 700 g caster sugar + 1 tsp agar-agar
- Fresh lemon juice1 whole lemon (approx. 40 ml)
Equipment
- •1 unlined copper jam pan or a large thick-bottomed pot
- •1 long wooden spoon
- •1 skimmer
- •4 to 5 jam jars of 250 ml with lids
- •1 jam funnel (optional but handy)
- •A few plates in the freezer (for the setting test)
Steps
- 1
Prepare the strawberries
Do NOT wash the strawberries under water (they soak up and lose their flavour). Wipe them quickly with a damp cloth. Hull them. Cut the largest ones in two or four. Keep some pieces for bite.
20 min
- 2
Macerate overnight
In the pan, mix the strawberries with the sugar and the lemon juice. Cover and leave to macerate 8 to 12 h at room temperature (or cool). The sugar will draw the juice from the strawberries and create a pink syrup. It is this step that sets a rustic jam apart from an extra-fine one.
8 to 12 h
- 3
First cooking
Bring to the boil over high heat. Carefully skim the pink foam that forms on the surface (it's what makes the jam cloudy if you don't). Let it boil 5 minutes, stirring gently. Turn off the heat and let it rest 2 h. This two-stage technique preserves the whole fruit pieces.
5 min cooking + 2 h rest
- 4
Second cooking and test
Put back on high heat and bring to a rolling boil. Cook 8 to 12 minutes depending on the thickness sought. To test: drop a dot on a cold plate taken from the freezer, wait 10 seconds, then push the dot with your finger. If it wrinkles and sets, it's ready. Otherwise, continue 2-3 min and test again.
8 to 12 min
- 5
Put into jars
During cooking, scald the jars and lids (3 min in boiling water, or 10 min in the oven at 100 °C). Fill the scalding-hot jars to 5 mm from the rim. Screw on immediately and turn the jar upside down for 5 min, the heat sterilises the lid and creates an air vacuum as it cools.
15 min
Storage
1 year in a cool, dry cupboard, away from light. Once opened, keep in the fridge and eat within the month. If you see mould on the jar, discard without hesitation (rare with sugar at 55%, but possible if the jar was contaminated).
How to use it
On toast at breakfast. In a plain yogurt. As a filling for tarts and cakes. As a coulis (thinned with a little water) over ice cream or a pancake.
Health properties
- A concentrated source of the strawberry's antioxidants (anthocyanins, ellagitannins), partly preserved despite the cooking
- Residual vitamin C (50% destroyed by cooking, but the lemon adds more)
- The gustatory and nutritional pleasure of an out-of-season fruit, a pillar of self-sufficiency
- A natural food without industrial preservatives
These preparations belong to cooking and herbal tradition: they nourish and support, do not “cure” anything and replace no treatment. Ask a doctor or pharmacist before prolonged use, if under treatment, pregnant or breastfeeding, or for a child. Follow the stated storage precautions strictly.
Precautions
Very high in sugar (approx. 55-65% in the end), to dose in a diabetic diet. The jar must be well sterilised and the lid well sealed (the upside-down test), otherwise a risk of mould. Do not reuse chipped jars. The added pectin of “jam sugar” is an additive (E440), harmless but worth knowing.
Sources & tradition
- · Christine Ferber, Mes confitures (2002), the French reference
- · European peasant tradition
- · Pam Corbin, The River Cottage Preserves Handbook (2008)