Making a small batch of jam from berries picked in my garden during the summer is a perfect way to remember the warm summer days. Blackberries are packed with antioxidants and vitamins so it’s great to find ways to include them in our diet.

I have been testing out ChatGpt for recipe suggestions, with prompts to ensure the the results I am looking for. This is a one-jar recipe for blackberry jam that’s perfect for testing sweetness, texture, and how much tartness you like before making a full batch. It’ll give you roughly 250–300 ml of jam, enough for a week or two of breakfasts and baking.

Ingredients

• 500 g frozen blackberries
• 150 g sugar (go down to 125 g for sharper flavour)
• ½ medium tart apple (Granny Smith, peeled and grated)
• 1 tbsp lemon juice
• Tiny pinch of salt (optional)
• 1-2 tbsp pectin (if needed)

Putting it together

1. Thaw the berries
   Place the frozen blackberries in a small heavy pot and allow to thaw slightly. Warm gently over low heat until they release juice and soften — about 15 minutes.
2. Remove most seeds
   Mash the berries lightly, then press about two-thirds through a fine sieve or food mill. Keep the remaining third unstrained for texture. Return everything to the pot.
3. Add sugar, apple, lemon, salt
   Stir everything together and let sit for 10 minutes so the sugar starts to draw out juice and dissolve a little.
4. Simmer slowly
   Bring to a steady boil over medium heat, then lower to a gentle simmer. Stir often. Cook for 20–25 minutes until thickened and glossy.
5. Check for set
   Spoon a little jam onto a chilled plate. If it wrinkles or holds its shape when nudged, it’s ready. Otherwise simmer another 5 minutes. My jam was not ready so I sprinkled in 2 tbsp pectin and cooked it for another 5-8 minutes. The result was still softer, runnier than other jams but tastes great.
6. Jar it
   Pour hot jam into a sterilised jar, seal, and cool. Keep in the fridge — best within 2–3 weeks.

Notes

• The grated apple gives natural pectin, body, and a hint of tartness.
• Stir gently toward the end to keep bits of fruit intact.
• If the jam thickens too much after cooling, stir in a teaspoon of warm water when serving.

The resu