Essential Tips for Making Jams and Preserves

Jam & Preserve Recipes

• Blackberry & vanilla jam
• Blackberry & lemon jam
• Raspberry jam
• Seville orange marmalade
• Strawberry jam
• Spiced plum jam
• Lemon curd
• Gooseberry & ginger jam
• Apple chutney

Recipes Using Jam

• Peanut butter & jam streusel bars
• Miniature jam tarts
• Homemade jammy dodgers
• 10-minute sponge pudding
• Bakewell tart
• Lemon & blackcurrant cheesecake
• Blackcurrant cake pops
• Chocolate marmalade cheesecake
• Lemon & chocolate sandwich cookies

Tips and Tricks

It has been (as regular readers may have noticed) quite the year of jam making for me. In the process of preserving everything I could lay my hands on, I've picked up a few tips about jamming and jellying, which I thought I'd share.

Gathering your harvest can be a somewhat incremental process, particularly in the case of hedgerow berries, which are prone to mould before you have chance to cook them. Reduce the stress by popping handfuls of berries into the freezer as and when you pick them, and preserving from frozen.

A basic ratio for most jams is equal parts fruit and sugar, by weight. You can experiment and mess around with this to your taste, of course, but it seems to be a pretty reliable starting point. You can use any kind of sugar.

Jam won't set if it doesn't have sufficient pectin. If in doubt, grate in half a large cooking apple per kilo (2lb) of fruit (making sure to leave the skin on). This will provide a pectin boost without affecting the flavour, and works out a lot cheaper than buying special "jam sugar", especially if you have your own apple tree.


Adding a little lemon juice (or citric acid, if you prefer to buy it as a powder) increases the acidity of the mixture, and will help the jam last longer. Lemon juice also contains pectin.

You could spend ages scraping 'scum' off the top of your boiling berries, and many recipes would have you believe this is an essential step, but personally I just wouldn't bother unless I was aiming for a clear jelly. In general, since I prefer my jams with lumps of fruit, it doesn't seem worth the effort to worry about a few bubbles.

The setting point of jam is about 104°C (220°F), but although a sugar thermometer is a worthwhile investment, you don't absolutely need one. Put a small plate in the freezer before you start. Then you can quickly check whether jam is going to set by dropping a little onto the cold plate; if it congeals and wrinkles when you push it, you're good to go.

There are several methods for sterilizing jam jars. Running them through a dishwasher cycle is probably the easiest. You can also half-fill the jars with warm water and put them in the oven at 100°C (212°F) or a half-filled pan of water. It's important to heat glass gradually so it doesn't break; start with warm water and increase the temperature to boiling point. Lids don't sterilize properly, so you shouldn't reuse lids unless you put some clean parchment paper between the jar and the lid.

I've also gathered that there are a few differences in methodology between the US and the UK. In particular, the Brits tend to just throw the jam in the jar and leave it be, while the Americans have all sorts of added steps like pressure- or water-bath canning (neither of which I'd ever heard of before). The US Department of Agriculture has even funded a centre to research food preservation, who produce pretty comprehensive guidelines that are well worth a read. I do things the British way, just because that's how I've been taught, but some time I'd like to compare the two styles properly.