How to Make Homemade Jam: A Beginner's Complete Guide

There's something deeply satisfying about a jar of homemade jam, especially the bright colour, the intense fruit flavour, and the crisp pop of a properly sealed lid. Making jam at home is far easier than most people think, and with the right glass jars and a bit of know-how, you'll be filling your shelves in no time.

What You'll Need


Equipment

 

  • Large, heavy-bottomed jam pan (or stainless-steel saucepan)
  • Long-handled wooden spoon
  • Jam thermometer (recommended)
  • Ladle and jam funnel
  • Sterilised glass jam jars with lids


Ingredients 
(Makes approx. 4 x 340g jars)

  • 1kg fresh fruit (strawberries, raspberries, plums, blackberries - your choice)
  • 800g-1kg granulated sugar (adjust to fruit's natural pectin content)
  • Juice of 1 lemon

Step 1: Prepare Your Fruit

Wash and hull the fruit. Remove any bruised or damaged pieces, as they'll affect the flavour and shelf life. For stone fruits (plums, damsons), remove stones now.

Step 2: Sterilise Your Jars

This step is critical for food safety. Preheat your oven to 140°C, place clean jars upside-down on a baking tray, and heat for 15 minutes. Boil lids separately for 5 minutes. For a more detailed walkthrough on how to ensure your containers are perfectly safe, check out our complete guide to sterilising glass jars here.

Step 3: Cook the Fruit

Place fruit in your jam pan with the lemon juice. Cook gently over a medium heat, stirring frequently, until the fruit has softened and broken down. This usually takes around 10-15 minutes, depending on the fruit.

Step 4: Add Sugar and Dissolve Completely

Add sugar and stir continuously over a low heat until every grain has dissolved. This is important: if sugar crystals remain when the jam boils, your finished jam may crystallise in the jar.

Step 5: Reach a Rolling Boil

Turn the heat to high and bring to a rapid, rolling boil. This is a boil that cannot be stirred down. Time it: most jams need 5-15 minutes of a rolling boil to set.

Step 6: Test for Setting Point

The wrinkle test: Drop a teaspoon of jam onto a cold plate (kept in the freezer). Push it with your finger - if it wrinkles and holds its shape, it's ready. If it runs, boil for another 2-3 minutes and re-test.

Using a thermometer: Setting point is 104°C (220°F).

Pro Tip: Always use a heavy-bottomed pan to prevent the sugar from burning at the bottom.

Step 7: Pot and Seal

Remove pan from heat. Skim any foam from the surface. Ladle hot jam into your warm sterilised jars using a jam funnel. Fill to within 5mm of the rim. Immediately seal with lids and invert the jars for 1 minute to create a vacuum seal, then turn right-side up.

Fruit Pectin Guide

Fruit

Blackcurrants

Plums

Raspberries

Apricots

Strawberries

Natural Pectin

High

Medium-High

Low-Medium

Medium

Low

Sugar Ratio

750g sugar per 1kg fruit

800g sugar per 1kg fruit

900g sugar per 1kg fruit

900g sugar per 1kg fruit

1kg sugar per 1kg fruit + lemon

Low-pectin fruits benefit from the addition of jam sugar (with added pectin) or the juice of a lemon.

Storage and Shelf Life

Properly sealed homemade jam lasts up to 12 months in a cool, dark place. Once opened, store in the fridge and use within 4-6 weeks.

Choosing the Right Jars

The best jars for homemade jam are:

Browse The Pack Stock's full range of glass jam jars in a variety of sizes, ranging from 110ml miniatures perfect for wedding favours to 720ml large catering jars.

Ready to start your preserving journey? 

Discover the same high-quality glass jars and bottles used by professionals. We offer certified quality, fast shipping, and flexible orders to suit both home cooks and large producers.

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