Who would have thought that the bottle of delicious mango chutney I bought from Jen at Dundee markets on the weekend was only possible because of a directive in 1795 from Napoleon, who offered a reward to anyone who could develop a safe, reliable food preservation method to sure up supply for his constantly travelling army?
Now we have a culture of tasty homemade and commercial ready-to-use sauces, jams, relishes, pastes and even pickled eggs.
The practice of preservation, canning or bottling fresh produce drove one of the biggest food revolutions in the modern world.
Bottling and preserving fruits and vegetables was a feature of Depression-era kitchens in Australia; it allowed food to remain edible longer, which was important when food was in short supply.
Much like fruit and vegetables, eggs were seasonal, and so pickling them became very common.
Bottling was a household practice in Australia when the Brits were still indulging in the risky process of open kettle canning. Food was cooked in a large, open-air pot known as a kettle and then thrown into a hot, sterilised jar, which was sealed.
The process has been discredited and discouraged since the end of World War II. It was officially firmly recommended against in 1989 as it was found to carry a high risk of illness and even death because it can promote the growth of botulism.
You can presume that many jars of home preserved products have botulism spores in them, but the spores are unable to cause any harm due to the low pH of the products killing off disease through high acidity.
Moulds in jars, seen and unseen, can raise the pH of your jam or pickled goods above the safety level of 4.6, allowing botulism spores to come out of dormancy, producing deadly toxins as a by product.
All preserve jars initially contain millions of mould spores in the space between the filled jar and the lid placed on top, but are killed off during the heat processing of the jar.
The authors of Putting Food By explain what happened to one family when mould spores in a jar of tomato weren’t killed off.
“Early in 1974, there were two deaths from botulism poisoning traced directly to homecanned tomatoes and tomato juice…
“Public health officers discovered what actually allowed the spores of C. botulinum to make the toxin that killed the victims. Common bacteria or moulds grew in the food in the jars and thereby reduced the acidity because the natural acid in the tomatoes was metabolised by the microorganisms as they grew and developed.
“It was established after compassionate, but thorough, investigation that these bacteria or moulds survived either because the tomatoes were canned by the discredited open-kettle method, or entered under the lid of a jar that wasn’t adequately sealed.
“Inadequate processing is virtually always the cause of food poisoning that develops during shelf life.”
Putting Food By warns: “It is not safe to remove the mould and eat the food, because certain types of mould reduce the acidity to a point where botulinus spores may develop.” Preserving food is quite safe if you follow basic hygiene rules. First, sterilise the jars by washing in hot soapy water and rinsing well. Boil the jars in a deep saucepan for about 10 minutes. Let the jars dry and then heat oven to 150 ºC and place jars inside for 15 minutes. Prepare your fruit or vegetable and soak them in cold water. Add sugar to your ingredients and boil them in a large pot, stirring until the syrup thickens.
Transfer the syrup into the sterilised jar, leaving a few centimetres of space between the syrup and the lid. Tighten the lid and invert the jar, turning it upright after five minutes. Leave the jar to cool. Afterwards store it in the fridge or any cool, dark place.
The preserves should then last for months.
Preserves and jams allow room for creativity when you take advantage of seasonal fruits and vegetables, bulk buys or large harvests. They’re easy, delicious, and can be a fantastic homemade gift for birthdays, get togethers or Christmas with the family.