With National Preserve Week running from 25 July-2 August, we chat to Rosemary Jameson, founder of the Guild of Jam and Preserve Makers, about making the most out of your summer produce

How does preserving work?

“Most foods can be preserved by lowering the moisture content in some way. This isn’t always done by cooking - air drying, dehydration and salting are all well-established means of preservation. All yeasts, moulds and bacteria need moisture to thrive; if you lower the moisture content then it becomes inhospitable to these organisms.”

What equipment would someone need to get started

“Just use everyday kitchen equipment until you get bitten by the bug! Use the biggest pan you have and ensure it is only one third full before you start cooking, even if it means cooking in two batches. The preservation of food at ambient temperature has been going on since Stone Age times, and they couldn’t order from Amazon!”

Do you have any health and safety tips?

“Once you have made your lovely preserve, you need to stop moisture from getting back into it. This will happen even with moisture from the air by osmotic pressure and before you know it, your jam will have a nice little mouldy hat. Once made, jar up while hot, fill to the top of the jar and put on the lid to seal immediately. Your preserves will then last in good condition for many years – and no need to refrigerate.”

How did you get into preserving?

“I learned as a young child by watching my mother – I was fascinated, she was not! She hated cooking of any description but made delicious meals. We had to preserve what we had grown though so it had to be done. I made my first chutney (while the adults were out) aged 11 because I was bored.”

Do you have to use sugar?

“Yes, and in the correct proportions. Do not meddle with the recipes; sugar, along with salt and vinegar, is nature’s preservative. The first jam known to be made was in the first century.”

What preserves would you recommend making this month?

“All of the summer fruit jams (blackcurrant, raspberry and gooseberry), cordials (elderflower), herb jellies and fruit leathers.”

With summer fairs cancelled this year, how can people continue to support independent preservers?

“Just buy local, buy better and eat less. Good quality food may be more expensive at times, but because it is more satisfying you don’t need to eat lots of ‘add-ons’ to make it a tasty experience. [They use] less additives and pesticides, and every pound that you spend with an independent stays in the local community.

“We are running The Stay At Home Jam Festival online from July 25 – August 2 to support National Preserving Week. There will be lots of fun and games to join in with, just like a real festival, and a produce and craft ‘tent’ where you can list your independent business free of charge.”