Successful polytunnel gardeners will soon discover that gardening is just one part of the picture when it comes to eating their own produce all year round. Almost as important as growing the food in the first place is how you will prepare that food for the plate. While there is nothing better than taking your own home-grown fresh produce from soil to plate in moments, there will also be times when you have more produce to harvest than you can eat immediately. Preserving food can become a pressing concern for eco-friendly and sustainable gardeners, and ‘canning’ is part of that preserving picture.
What is Canning?
‘Canning’ is the name given to preserving food in glass jars or bottles. Canning is better known in the US and Canada than it is in the UK. While the UK has a long history of jams and pickles, this sort of preserving is not as widespread here as it is across the pond. When North Americans refer to canning, they are talking about the safe preservation of a wide range of different home-grown foods using water canning or pressure canning techniques.
Why Switch to US-Style Canning Techniques?
In the UK, we are more used to placing hot preserves (usually with high levels of sugar or vinegar) into sterilised jars, then leaving it at that. But in America, processing of filled, sealed jars in a hot water bath or pressure canner is more common. The fact of the matter is that modern research and science show that this method is far, far safer for human health.
The traditional British way of doing things does come with its health risks, as not all bacteria are eliminated entirely in ‘open kettle canning’. While some people are perfectly happy with the risk levels involved, it could be worthwhile considering a switch to US style canning if you are preserving a lot of your own produce at home. It is a great idea to process filled jars in a hot water bath or pressure canner to make sure that they are safely preserved for you to enjoy later in the year.
What do I Need For Canning?
To safely can food from your polytunnel, you will need:
- Jars (ideally traditional mason jars with two part seal-able lids.)
- A large, deep pan large enough to submerge your jars in water. (a rack to place within this pan can also be helpful, in order to stop jars from clanking together during processing).
- For low-acid food preservation (preserving fresh vegetables, for example) you must have a pressure cooker/ pressure canner in order to pressure can these preserves.
There is a lot to learn about how to process filled jars and make these safe for shelf storage over time. Fortunately, while canning of this safe, modern type is not common in the UK as it is elsewhere, there is a growing awareness of these techniques and a growing interest. Information on how to go about canning your polytunnel produce can be found online at a number of locations.
Do you do any home canning here in the UK? If you have any wisdom to share, please do so in the comments below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.