Potato queue at Kingsbury Farm, Church Street, Dunstable in April 1917 [Z50/36/142]
Monday 19th February 1917: Poor crops in many parts of the country have led to a serious shortage of potatoes. The Board of Agriculture has asked consumers to economise in their use, both by eating less and by considering their cooking methods. Much of a potato is made up of water, leaving only about one-quarter which is of direct value as food; the most valuable part being the part next to the skin. The most common method of cooking potatoes is to peel them, then put them into cold water and boil them. This wasteful approach can lead to the loss of as much as one-fifth of the whole tuber, with the peelings containing a larger percentage of nutritious solids than the rest of the potato. Boiling then dissolves out soluble ingredients and breaks down the surface into the water, which is thrown away. Experiments have shown that around 15.8% of the protein, 18.8% of the minerals, and about 3% of the carbohydrates are lost in cooking a potato this way. If they are plunged into boiling water immediately after paring on 8.2% of protein, 18% of minerals, and a small amount of starch is lost. When potatoes are boiled in their jackets only 1% of protein, just over 3% of minerals, and almost no starch is lost.
To reduce this waste people are advised to either boil or steam potatoes in their jackets, after making a cut in each end to allow the escape of steam. When baking potatoes they should be pricked or cut and then baked slowly. If potatoes must be peeled, then they should be steamed or cooked in the smallest possible amount of boiling water, which should then be reused in soups. Adding salt will also help to reduce the loss of nutrients. An alternative is to pare the potatoes as thinly as possible, then slice them for use in vegetable or meat pies. Potatoes may also be replaced by turnips and swedes, which should be sliced and steamed rather than boiled.
Source: Leighton Buzzard Observer, 20th February 1917