Even though refrigerators have only been commercially available since the beginning of the 20th century, people have been preserving their food through other methods for substantially longer, according to Washington State University. There are a number of ways to keep food fresher for longer, and while some are more practical than others these days, it’s worth any chef’s time to understand each method. In doing so, you might gain insight into the food that fuels our lives.
1. Salt or sugar
According to the Scientific American, using salt or sugar is one of the more ancient forms of preservation. Salt, namely sodium chloride, and sugar – sucrose – has been used to prevent spoilage in a number of foods, including bacon, ham, pork, fruit preserves and various jams and jellies. So, how does either approach actually work? The most obvious and effective method is dehydration – by limiting how much water is inside a given food , you’re preventing the spread and growth of certain bacteria. One of the more common methods of salting is to soak food in brine for an extended period of time. Be aware, though, that molds exist even in foods treated with higher concentrations of sugar or salt. Some yeast can thrive in foods with especially high levels of sugar.
In many ways, the drying method has a lot in common with salting and sugaring. In essence, you’re trying to pull out moisture to prevent bacterial growth. However, as Colorado State University pointed out, it’s an easier and more economically viable method many ways. Though it is often done with modern microwaves, drying via the sun is also possible and has been used by many pre-industrial civilizations.All you need is an area with low humidity and temperatures between 120 and 150 degrees Fahrenheit, according to the University of Minnesota. Food should take three to four days to dry outside if the humidity is less than 20 percent. Additionally, it’s a good idea to keep food in several bags as to negate the effect of bugs and pollutants.
While some methods want to entirely do away with bacteria, fermentation relies heavily upon these microorganisms, according to the University of Wisconsin. In fact, many of these foods need bacteria to develop their specific flavors. For instance, bacteria eat the lactose that allows yogurt and cheese to coagulate. However, when fermenting food, it’s important to ensure the provisions are in the proper levels of salt, as this is what draws out the sugar bacteria consumes. The right heat is also crucial in the fermentation process, and anything between 68 and 72 degrees Fahrenheit is optimal. It’s important to note that fermentation can be a lengthy process as it can take up to four weeks depending upon the food.
No two preservation methods are the same, so make sure to experiment with as many as possible in your kitchen.