Home canning of meat products is practically unheard of in Europe, but quite common in America as a method of preserving game or bulk purchased meat without the need for a freezer. As an idea, preserving cooked, as opposed to raw, meat, might not appeal to everyone. But it has its uses. Quite apart from the space saved in the freezer, canned meat is immune from power outages and does not need defrosting before use. Can a stew, for instance, and all you need to do is drop it into a pan to heat and add beurre manié to thicken. Here, I am canning cat food, prior to leaving our two boys, Tigger and Foggy, in a cattery for the first time – in the hope that familiar food might lessen the stress of their temporary surroundings. Cooked meat may not be as nutritious as their usual raw chicken, but it is a clean and convenient alternative for holidays, and certainly better for them than the vast majority of ‘quality’ commercial pet foods.

Pressure canning is the only recommended method for safe canning of fresh meat, and you will need a purpose-built canner with a proper pressure gauge. Most food molds are destroyed by boiling, but bacteria like the deadly C.botulinum require a higher temperature. In a pressure cooker, the pressure created by the steam inside the container allows food to cook at temperatures above 100°C: the higher the flame, the hotter the steam, and the higher the pressure. However, with no pressure gauge, there is no way to monitor the actual temperatures inside a standard domestic pressure cooker. To ensure that all harmful bacteria are killed, meat must be processed at around 115°C or 10lbs pressure. I could not find any European retailer of domestic pressure canners, so I bought my 23-quart Presto canner on-line from US retailer, [1] Goodman’s, in Miami, FL.

I use Familia Wiss ‘Le Parfait’ Terrine jars, which seal with a flat metal cap kept in place, during the canning process, by a loose-fitting screw lid. They come in various sizes and are, of course, re-useable. Hygiene is key to the whole canning process to prevent any nasties contaminating the jar contents. Before starting any preparation, wash all the jars (even brand new ones) in hot soapy water, rince, and allow to air-dry. When you are ready to start filling the jars, boil a kettle and fill each jar with boiling water. Empty and drain at the last minute. The jars will be hot, so you will find they dry almost immediately. Put all the caps into a saucepan of boiling water, and use a pair of tongs to lift them out individually, as needed.

Recipes for home canning are widely available on American websites such as [2] Backwoods Home Magazine. For canned cat food, I simply make up [3] Feline Future’s Instincts TC supplement with chicken stock and add it to raw lean chicken and chicken liver. If you are buying a canner, it will also come with detailed user instructions and a few recipes.

Meat can be processed raw or cooked, with bones or without. Though, naturally, pet food does not contain bones, as cooked bones can splinter. Whatever you choose to can, whether meat, fruit or vegetables, always use perfectly fresh or, where appropriate, ripe, produce. Never attempt to can something just to save it from spoiling. Although the heat of the canning process should kill off any micro-organisms, the produce is, at best, likely to be discoloured and unappetising.

So, here I am with a bowl full of prepared cat food, a couple of rows of hot water-filled jars, a boiling saucepan full of metal caps and a heap of screw lids. I tip the water out of 2 or 3 jars at a time and drain them, allowing the others to remain hot until the last minute. Because I am canning food for two greedy cats, I carefully weigh each jar as I fill it, ensuring that each will contain two meals while avoiding waste. For other canning jobs, you just need to be sure to fill within about 1″ of the lip of the jar, allowing room for expansion during processing.

Next, I wipe carefully around the lip of each jar with a clean muslin, fish a metal cap out of the saucepan and seat it on the jar. I screw on the lids till they are just tight enough to hold the cap on. These lids are designed to allow air to escape from the jar during canning, so they do not tighten fully. If you over-tighten them, you will find that they easily cross-thread.

Follow the processing instructions for your particular canner, timing the process from the moment the correct pressure is reached. When time is up, allow the canner to cool and the pressure to drop completely before opening. By this time, the caps on the jars should have formed a vacuum. You should now remove the screw lids and test each of the caps. It should not be possible to easily prise the cap off with your fingernails. If you can, the process hasn’t worked properly and you now have two options: either use the produce straight away, or reprocess again from scratch. Otherwise, dry and polish the jars with a teacloth and store in a cool dry place.