shortening

• when you rub fat into flour, you cover the flour particles with fat - this gives the flour particles a waterproof coating
• the waterproof coating prevents long gluten molecules forming when water is added to the flour
• this means the dough cannot become stretchy and baked goods like shortbread keep a 'short' texture - hence the name shortening
• shortening is also used when making filled pies and tarts - its helpful because the base doesnt rise and forms a solid case
• some fats are called 'shortening' they have 100 percent fat content which helps stop gluten formation and prevents steam from raising the food