In a pickle? The rules to preserving the surplus of the season

Sure, you don't have to make these things, but everybody can. They're not technically difficult, and in many ways they are on the easier end of the cooking spectrum. (If anything, jam can be harder to master than brown sauce.) What's more, a small amount of your own mustard or fruit syrup or marmalade can enhance innumerable meals.

Okay, so if you want to put things up for a rainy day, if you want to store and preserve and stockpile your harvest (or other people's harvests) when the ingredients are in peak season, there are some rules. Yep, boring old rules. But by following a few simple instructions, your jam will set. Your sauce won't ferment. Your fruit won't go mouldy. There are only a handful of rules, but by following them you're far more assured of success. Ignore them at your peril.

We've given you instructions on how to sterilise your bottles and jars; how to store them; how to tell if your jelly is right; and how to avoid your jam getting sugar crystals in it. Once you've mastered these, you may well come up with your own techniques, your own routines, but if you're new to the world of putting stuff in jars to eat months later, it's worth having a good read through now, and perhaps refreshing your memory before you cook each recipe, just to be sure the effort you put in today will give you a surfeit of great things to eat later.

This is the big one. In the age of refrigeration we've often forgotten how much mould and yeast thrive when left unchecked. You can preserve things through excluding oxygen (tight-fitting lids), introducing an acid (pickled foods), and by adding enough sugar or salt. But even then it's important to start with really clean implements, and to store things in sterilised jars with sterile lids. So wash your storing jars or containers really well before sterilising.

The heat method

(a dishwasher is a good place to start)

Heat kills bugs, and bugs can cause your preserves to lose quality, or even go off. If you want to sterilise just one bottle, or a few jars, you can place them in a saucepan of cold water, on their sides, making sure they're full of water and submerged. Put their lids in there too. Bring this pot to the boil and simmer for 10 minutes. This will kill just about all the bugs you're worried about. The only downside of this method is that it is a little tricky to take hot bottles from a pot of boiling water, though there are special tongs on the market to help you. A good thing to note is that hot sauces and jams will crack a cold jar, and this method allows you to have your jars pre-warmed ready to pour in a hot conserve. Dishwashers, with a hot rinse cycle, also sterilise the jars, so that could be an easier method. Be sure, when dealing with hot jars, not to put them onto a cold surface or they will crack. Always put them onto a wooden board. Cold jars will also crack if they have very hot things put in them, so warm the jars a little first, using warm water or similar.

The microwave method

Don't do this to the wrong type of lid - metal ones - but jars can be sterilised effectively in the microwave because yeasts and bacteria are killed while the glass stays inert. Simply put the jars and lids in the microwave for one minute on High.

The rules for storing your preserves are fairly common sense to most cooks. Heat and light are the enemy of quality most of the time, so a cool, dark place is ideal. Somewhere that has air, so it doesn't breed mould, is also handy. Think of a dry cellar as the perfect place, because it's really stable in temperature and unlikely to get above 10-12C. But a pantry that is closed, that doesn't get too warm, is just about as good. Our suggested storage times are based on a decent home pantry that is relatively cool and dark compared to the rest of the house. In tropical climes, you'll want to shorten those times as need be.

You can use any jar that seals well and can be cleaned properly. Generally a jar that has a wide opening is better, as is one that ideally holds about 300ml, which is about the right amount of jam to have open at one time. For bottles, we tend to use big-mouthed ones for most uses, including passata and tomato sauce, though in a pinch we use beer bottles. The big downside is that if the sauce is nicely thick, it's hard to get from a beer bottle, and you can't see how much is in the bottle (or, in the case of passata, if the top has gone a little, ahem, mouldy after being left in the fridge for too long). We reuse jars and bottles constantly, discarding any with chipped edges, and always checking the lids to ensure they're still able to seal. For our preserves we use Fowlers jars, with their reusable lids and spring clips, and sometimes Ball canning jars, which are simpler to use, though nowhere near as robust.

Oh, the pan. Yes, the pan. You can make jam in any saucepan. But if you want a really great jam, a specialist jam pan is pretty much essential. The reason is that you want to heat your jam quickly and evenly. You want low sides so that any superfluous moisture evaporates quickly. Jam pans are big, wide things, with a great conductive base, such as copper (though aluminium is second best). The good ones have some weight to them to help distribute heat. The sides flare out, making it easy to stir your jam, while at the same time these low, flared sides help liquids evaporate quicker, too. You can use a saucepan, but make it a wide rather than tall one, and ideally one with a solid, heavy base. Just a note about copper jam pans: it's only when you add sugar to the pan that it's considered food safe, so precooked fruit (such as marmalade) is best transferred to the jam pan only when the sugar is added.