Water for Food Preservation – Everything You Need to Know
By Uma Campbell
Food is perishable by nature. It easily falls victim to bacteria and fungi and soon starts to degrade. Food spoilage can have fatal consequences. Traditional food preservation methods have been used over the years to protect food supplies from spoilage. Although these methods are effective, they have a negative impact on foods’ taste and flavor. The modern day, enlightened consumer is no longer interested in the not-so-fresh flavors of food products that use chemical preservatives. These concerns have led preservative industries to focus on preserving food in as close to its natural state as possible.
Canning Methods in Food Preservation
Water is an important ingredient in the successful preservation of food. This simple ingredient is easily accessible and makes it possible to preserve your own food. One of the preserving methods that dates back to the industrial revolution is canning. The basic idea of the canning process is to remove oxygen, which creates a conducive atmosphere for bacteria to grow. The two most common canning methods are:
Boiling Water Bath Method
The boiling water method involves storing food in airtight jars which are heated, completely covered with boiling water, and then cooked for a specific time. After the process is complete, the jars cool and a vacuum seal is formed. This method is safe for acidic foods like tomatoes, jellies, and fruits.
Pressure Canning Method
Pressure canning involves placing jars of food in 2-3 inches of water in a special pressure cooker. Pressure canning is the only safe preservation method for meat, poultry, and seafood because of the presence of a microorganism called Clostridium botulinum. These bacteria can form spores that can withstand boiling temperatures and then produce deadly toxins when they begin to grow, especially in low-oxygen and low-acid environments. To kill them, a temperature of at least 240°F is needed – a higher temperature that boiling water reaches. Therefore, the only way to destroy these spores is through pressure canning at 240°F or above. Use this method for low-alkaline foods.
The Science of Water Activity in Food Preservation
Fruits, vegetables and meats are primarily constructed from molecules of water (though essentially all foods contain water). However, it must be noted that the moisture content of a food is not the same thing as its water activity. A variety of foods with the same moisture content can have varying water activity. It is also important to realize that water activity cannot be measured at home, so you will always need to follow science-based directions when using water in food preservation. To maintain a useful shelf life of food, it is necessary to control the water activity to a low point that will not allow the growth of bacteria.
The Final Take
Water is an essential part of life. But it’s also a useful tool in preserving food, which is just one more reason to deeply consider engaging in measures aimed at conserving water. As long as you’re able to master safe and proper methods of preserving food, you’ll enjoy savoring your favorite dishes without having to worry about their safety.
Uma Campbell is a yoga instructor and freelance writer. She currently lives in Southern California. She enjoys writing about meditation, natural medicine, and home design. Her interests include home decor, yoga, and running. She also really loves crafting and has her own line of homemade jewelry. She lives alone with her cat and two turtles.