In a previous era preserving food was a common, everyday activity, dependant on the season, availability and local conditions. Summer fruit and vegetables were preserved when they were is season. Meat was slaughtered in late autumn with the first ground frosts. In the absence of refrigeration populations had no choice but to preserve food according to availability and the methods passed down from one generation to the next. Preserved food would have formed a much larger portion of mankind’s everyday diet than it does today.
It is impossible to talk about preserving food without talking about spoilage for, at heart, food preservation is about preventing putrification and rot. Applying some very simple techniques can arrest the process of both and preserve food for lengthy periods of time allowing us to eat food either out of season, in times of scarcity or simply to relish the sheer number of strong, tangible and desirable flavours that preserved foods deliver.
A number of factors cause food to decay: warmth, oxygen, moisture, light, enzymes and microorganisms. To prevent food from spoiling some obvious, straight-forward techniques can be relied upon that involve little or no thought, such as storing dry food or liquid oils in cool, dark, oxygen free containers.
Controlling microorganisms, some of the most potent food spoilers (or preservers) on the other hand, is a somewhat more complex exercise involving a basic level of understanding of how microorganisms work either to our benefit or to our detriment. Don’t panic – not a PhD knowledge in microbiology. Rather simple age-old proven tips on how to control their activity.
The role of microorganisms in food spoilage as well as food preservation
As far as food is concerned microorganisms can exist in three states: harmful, harmless, beneficial. The microorganisms that thrive on moist, warm, aerated food are pathogenic. However, not all microorganisms that live in or on food are lethal to human beings. Quite the reverse. Were all microorganisms pathogenic we, as a species, would simply not exist since pretty much everything we touch, breath or ingest contains some form of microorganism. Many microorganisms that we incidentally ingest or inhale are pretty harmless – neither friend nor foe.
Some microorganisms are foe and will cause us great harm when ingested such as salmonella, clostridium botulinum, e-coli or listeria. Careful handling, knowledge of what causes them to flourish and an understanding of what prevents them from contaminating our food ensures the consumption of food free from pathogens.
Then there are the beneficial bacteria known as Lactic Acid Bacteria or LABs. LABs are ubiquitous – in the air, the soil, on plants and in and on us. It is the microscopic family of LABs which when cultivated correctly preserve, rather than spoil, our food by secreting lactic acid. Interestingly, LABs are not only responsible for preserving our food they are highly beneficial and necessary for our continued well-being and good health.