30.2 What fat does in baking

What fats are, and the kinds a kitchen keeps, from butter and lard to shortening and oil, are covered with fats and oils. see chapter 19: Fats and oils

In a dough or batter, fat has four jobs that shape the eating.

• Tenderness. Worked in in large enough amounts, fat cuts the gluten strands in flour short. That is why baking fats are called shortenings. Lard was the classic one.
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• Lightness. When fat is beaten with a paddle, it can build up a mass of small air pockets. This is its creaming ability, and it matters most in cakes: a fat that creams well gives a lighter cake.
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• Ease of handling. Fat lets the gluten network stretch more easily, and makes the dough easier to mix and to work. Bakers call this lubrication.
• Moistness. Fat slows the drying out of both doughs and cake batters. For this job a shortening that is 100% fat does better than butter or margarine, which are not all fat.
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Fat also brings food energy in concentrated form, and many of the fatty acids the body needs.

Choosing a fat by its plastic range

Butter falls short here. At 10°C (50°F) it is close to too hard to work, and at 27°C (80°F) it is already too soft. The plastic range of each kitchen fat is compared with fats and oils. see chapter 19: The fats a kitchen uses: butter, lard, shortening, oils