Vegetable drying is a little more complicated than fruit drying, just as vegetable canning is more complicated than fruit canning.  Blanching is an important part of the operation.  It makes vegetable drying satisfactory as well as easy and simple, just as it makes vegetable canning possible.

However, there is one difference between blanching vegetables for canning and blanching them for drying.  After repeated experiments it has been found that for drying purposes it is best to blanch all vegetables in steam rather than in boiling water.  In vegetable canning we blanch almost all vegetables in boiling water, usually steaming only the members of the “green” family.

So remember that for drying all vegetables are blanched in steam.  To do this steaming you can use your ordinary household steamer, such as you use for steaming brown breads and suet puddings, or you can simply place a colander over boiling water in a kettle.  Do not allow the colander to touch the water.  If you are fortunate enough to possess a pressure cooker, steam the vegetables for drying in it.

Blanching is necessary for many reasons.  It removes the strong flavors, objectionable to many people.  Beans, cabbage, turnips and onions have too strong a flavor if dried without blanching.  Furthermore, it starts the color to flowing, just as it does in canning.  It removes the sticky coating round vegetables.  Most vegetables have a protective covering to prevent evaporation.  The removal of this covering by blanching facilitates drying.  Blanching also relaxes the tissues, drives out the air and improves the capillary attraction, and as a result the drying is done in a much shorter period.  Products dry less rapidly when the texture is firm and the tissue contains air.

Blanching checks the ripening processes.  The ripening process is destroyed by heating and this is to be desired for drying purposes.

Blanching kills the cells and thus prevents the hay-like flavor so often noticed in unblanched products.  It prevents changes after drying, which otherwise will occur unless the water content is reduced to about five per cent.

Thorough blanching makes the product absolutely sanitary; no insect eggs exist after blanching and cold-dipping.

There is one precaution that must be followed:  Do not blanch too long.  Blanching too long seems to break down the cell structure, so that the product cannot be restored to its original color, shape or size.  Follow the blanching time-table for drying just as carefully as you follow the blanching time-table for canning.

After the blanching comes the cold-dip.  For the benefit of new canning and drying enthusiasts, let me explain that by “cold-dip” we mean plunging the product immediately into a pan of very cold water or holding it under the cold-water faucet until the product is thoroughly cooled.  Do not let the product stand in cold water, as it would then lose more food value and absorb too much water.