Home Canning
What do we do with an excess of summer fruits? We make
jam. The same can’t be said when
courgettes start to take over our kitchen work surfaces. It’s usually all or
nothing with these types of vegetables and we can get rather fed up with them
after the hundredth search of the internet to find another recipe. Some of the
later ones end up unceremoniously into the compost bin when friend start to
turn them down.
There are things we can do to extend the eating season
though and with the looks of the Raised Beds Facebook page (we’re up to 14,000
members) our US friends seem to be one step ahead with preserving their
“Zuccini’s” There is a lot of interest
about “Canning” their summer crops for later use. This might have come about
from a warmer climate and the need for preserving food without a fridge over
the years.
What is the Canning Process?
The canning process dates back to the late 18th century in
France when the Emperor Napoleon Bonaparte, concerned about keeping his armies
fed, offered a cash prize to whoever could develop a reliable method of food
preservation.
After this came the idea of preserving food in bottles, like
wine. After 15 years of experimentation, it was found that if food is
sufficiently heated and sealed in an airtight container, it will not
spoil. No preservatives are necessary.
Putting food into metal cans came after by industries in the UK but the simple
glass bottling idea spread to America it was easily undertaken by individual
growers at home.
Home canning or bottling, is the process of preserving
foods, in particular, fruits, vegetables, and meats, by packing them into glass
jars and then heating the jars in a larger container to kill the organisms that
would create spoilage. Over the years special pressure cookers and jars have
been created to get the hotter temperatures to kill off bacteria and
microorganisms
Checking for quality
When a jar has cooled and is properly sealed, pressing the
dimple on the lid will not make any sound. An improperly sealed jar will allow
the dimple to move up and down, sometimes making a popping noise in much the
same way a shop bought jar would act.
Older jar variations had a ceramic seal inside a one-piece
zinc lid. Another method that is no longer recommended was the use of layer of
hot paraffin wax poured directly over the top of the food (especially jams and
jellies) to seal it from air, thus reducing growth of aerobic microorganisms
like mould.
While it is possible to safely preserve many kinds of
foodstuffs, home canning can expose consumers to botulism and other kinds of
food poisoning if done incorrectly so there are a lot of recommendations about
food safety. We here and closer to home tend to favour the pickling process,
which varies quite a bit from the American Canning process.
Pickling
Pickling began 4000 years ago using cucumbers native to
India. This was used as a way to
preserve food for out-of-season use and for long journeys, especially by sea.
Salt pork and salt beef were common staples for sailors before the days of
steam engines. Although the process was invented to preserve foods, pickles are
also made and eaten because people enjoy the resulting flavours. Pickling may
also improve the nutritional value of food by introducing B vitamins produced
by bacteria.
Pickling
The main difference is the food isn’t super-heated but
relies on a pH 4.6 or lower, which is sufficient to kill most bacteria.
Pickling can preserve perishable foods for months. Antimicrobial herbs and
spices, such as mustard seed, garlic, cinnamon or cloves, are often added. If
the food contains sufficient moisture, a pickling brine may be produced simply
by adding dry salt. For example, German sauerkraut and Korean kimchi are
produced by salting the vegetables to draw out excess water. Natural
fermentation at room temperature, by lactic acid bacteria, produces the
required acidity. Other pickles are made by placing vegetables in vinegar.
Unlike the canning process, pickling (which includes fermentation) also does
not require that the food be completely sterile before it is sealed. The
acidity or salinity of the solution, the temperature of fermentation, and the
exclusion of oxygen determine which microorganisms dominate, and determine the flavour
of the end product.
Other Ideas
For those of us who aren't into canning or pickling, the
freezer is really our best friend. Besides freezing whole fruits and vegetables
at the peak of their ripeness, we can freeze batches of summer pesto,
containers of tomato sauce and apple sauce, and even garden herbs in olive oil
ice cubes. These are the foundation of quick weeknight meals in the busy months
ahead.
The process of dehydrating vegetables is worth looking into
as well. We won’t need expensive equipment either as a regular oven does the
job well. Courgettes dry out really well and can be just like crisps.
Maybe
I’ll start selling them, my latest get rich quick scheme.
