Water for food preservation
Water is an important ingredient in successful food preservation. Hard water contains larger amounts of minerals than soft water. A certain amount of calcium and magnesium salts is desirable to set the pectins in fruits and vegetables such as in canning peaches and pears. However, large amounts of minerals can toughen peas, beans and shrivel pickles. Hard water can cause cloudy liquid in canned fruits and vegetables as the high temperatures cause the minerals to settle out of the liquid, but it is not harmful.
A good example of the water dilemma is green beans. When canning, very soft water can cause mushy green beans, hard water is preferred. But, when blanching green beans for freezing, hard water will toughen them—softer water is then preferred. As a general guideline, avoid excessively soft or hard water in canning, freezing and pickling. Distilled bottled water is preferred to chemically softened water. Hard water can be made more acceptable by boiling it for 15 minutes and allowing the calcium and magnesium salts to settle out. In most cases soft water is preferred over hard water because it causes fewer problems.
Written by Deb Botzek-Linn, University of Minnesota Extension educator, 2011.