Denton and Lowe found that in general the fats and the oils having the highest percentage of unsaturated glycerides gave the shortest pastries. They found an exception in butter, which gave less shortening power than coconut oil, although moisture-free butter, with only the butter fat used, drained free of curd, produced a very tender pastry. Here the heating of the butter fat to render it moisture free may have affected its shortening power.

From data, Table 65, it can be seen that the order for different fats in the table varies in some cases according to whether the crushing or the breaking average is taken. Therefore, the results should be taken in groups rather than individual experiments. The oils, corn, cottonseed, and chicken gave the most tender pastries. The pastries next in order were obtained with second-grade lard, bulk lard, or when a temporary emulsion was made by shaking the oil and the water and then adding this emulsion quickly to the flour. The latter is a method often suggested in recipes, as it tends to produce a flakier and less crumbly pastry than when the oil is first mixed with the flour and the water added last.

Table 65*

Breaking and Crushing Strength of Different Pastries Made under Standardized Conditions. (Each Figure an Average of 48 Tests.) Temperature of Ingredients When Mixed 80°F. (Denton and Lowe)

*Published by courtesy of Dr. Louise Stanley, Chief, Bureau of Home Economics. Experimental work on pastry done at the Bureau of Home Economics, Washington, D. C.

+Average of 96 tests.

Puff pastry shortening. The puff pastry shortening is a product containing about 30 to 45 per cent of oleostearin and from 45 to 60 per cent of cottonseed or other vegetable oil. It is prepared by mixing the ingredients and heating to a common melting point, mixing, chilling in water, and working. The finished product has 7 to 10 per cent of moisture. It is very waxy, and is easily rolled in thin layers for use in puff pastry, for which it produces excellent results, but it is poor for ordinary pastry.

Butter and margarine. Butter and margarine gave a very hard pastry. The emulsified fats, such as butter, margarine, and puff pastry shortening, gave harder pastries than their moisture-free products. To render the butter and margarine moisture free, they were heated at 75°C.

Class results. Class results are in agreement with results by the shortometer. There is enough difference in the shortening power of different fats, so that pastries in which butter, lard, hydrogenated fats and oils, and oil have been used can be placed in order of tenderness by breaking with the fingers, if the pastry has been made under standardized conditions. Butter gives the hardest and toughest, and oil may give the most tender. The lards usually give more tender pastry than the hydrogenated fats or hydrogenated oils. Observing housekeepers often state that they obtain shorter pastry from second-grade lard, although the odor and flavor may not be so good as the first-grade lard. Second-grade lards contain a higher percentage of the unsaturated glycerides. Two types of pastry are obtained with oil. If the pastry is crumbly, the oil yields the most tender pastry of the series. However, if it is flaky, the pastry may be about as tough and hard as that with butter or like the lard. These two types are probably due to the temperature of the ingredients when mixed, the thoroughness with which the oil is mixed with the flour before the water is added, the extent of mixing the water with the flour, and the proportion of water. Longer mixing after the water is added seems to increase the flakiness of the pastry made with oil. For several quarters the class has had only flaky pastry with oil, the pastry being mixed 40 to 50 strokes with a three-tined fork.

Increasing the fat results in a more tender pastry. Increasing the water in a given recipe decreases the tenderness of pastry. If both fat and water are increased, the result depends upon the proportion of each used; but unless the increase in fat is very small, the resulting pastry is more tender, the fat having a greater effect than the water. The gluten of pastry flour cannot be developed to the extent that gluten of bread flour can; thus pastry flour gives a more tender pastry than bread flour if the conditions under which the pastries are made are standardized.

Effect of extent of mixing on shortness of pastry. The extent of mixing after the water is added affects the shortness of pastry. It is rather interesting that, although longer mixing, a great deal of handling, and rerolling tend to increase the toughness of pastry, mixing the water and flour with a fork or a utensil which cuts through the dough instead of packing it, as in Experiment 95B, for 40 to 50 strokes, usually gives a more tender pastry than mixing 20 to 30 strokes. But handling the pastry after it is mixed, i.e., kneading and rerolling, increases its toughness, though very careful rerolling may increase the flakiness without materially increasing its toughness.

Flakiness. Flakiness is considered a desirable quality in pastry. Melted fats and the oils usually give a more crumbly and a less flaky crust, although a flaky crust is often obtained with oil or melted fat. Bread flour tends to give a more flaky crust than soft-wheat flour. The temperature of the ingredients may affect the flakiness. With the harder fats there is a greater tendency for the fat to stay in layers, as flakiness depends upon the layers of fat and flour being separated by steam and probably to a lesser extent by air in the baking. The proportion of water to fat has some effect. When the proportion of water to fat exceeds or falls below a certain ratio, the pastry is less flaky. The extent of mixing the fat with the flour, as well as the method of combining the water, by mixing or by cutting the water into the fat and flour, may also influence the flakiness of the pastry. The method of handling the dough may have some effect. Rerolling and careful handling may increase flakiness and also toughness. The flakiness of pastry is also increased by rolling with thin layers of fat between layers of the dough.

Soaking of crust in baking pies. Excessive soaking of the crust during and after baking occurs most frequently with fruit pies, as cherry, blackberry, blueberry, and loganberry, and custard pies. Many suggestions to prevent soaking have been offered and these have been collected in Experiment 98. Tests, using pastry made in one batch and rolling all to the same thickness, have shown that partially baking the under crust before adding the filling only increases the soaking. Brushing the under crust with butter or fat aids to a certain extent, but for cooked or canned fruit thickening the juice before adding the filling to the pastry is the most effective means of preventing soaking. If fresh cherries or berries are used, then mixing flour or cornstarch with the sugar is as good as cooking the fruit first before adding it to the pie. The only advantage of cooking and thickening fresh fruit before adding the hot filling to the pastry is that it shortens the cooking time in the oven.

The best way to prevent soaking of the crust in custard pie has been mentioned in the chapter on eggs, that is, cooking the filling and pastry separately. If this is not desirable, scalding the milk before adding it to the eggs and using 3 eggs to a pint of milk help the custard to set more rapidly.