Various textures of baked goods are created by
Various textures of baked goods are created by the structures of their doughs and batters
§Water §Gluten proteins §Starch granules
§Breads and cakes are light and tender because the protein-starch mass is divided up by millions of tiny bubbles §Pastries are flaky because the protein-starch mass is interrupted by hundreds of thin layers of fat
§Doughs contain more flour than water and are stiff enough to be manipulated by hand §All of the water is bound to the gluten proteins and the surfaces of the starch molecules
§Batters contain more water than flour and are loose enough to pour §Most of the water is free liquid
§When a dough or batter is cooked, the starches absorb water, swell, and create a solid structure §Breads and cakes are sponge-like and the term used to describe it is crumb §The outer edge is called a crust
§Glutens consist mainly of protein, and are considered some of the largest protein molecules in the world §When dry they form a powder §When wet, they change their shape and form and break bonds with each other
§This means that gluten chains in doughs will change their shape under pressure, but resists the pressure and move back towards its original shape when the pressure is removed.
§This means that with wheat dough, the dough can expand to incorporate carbon dioxide gas produced by yeast, but resists enough that the bubble produced won’t thin to the breaking point
§ Gluten elasticity relaxes with time § In a well developed dough, the protein molecules have been organized and aligned § These aligned gluten molecules form weak bonds with each other § Because they are weak, the physical tension of the mass of dough itself gradually relaxes into a more malleable mass
§You have a lab Friday §You will be making buttermilk biscuits and completing a scientific lab investigation §Your independent variable will be the time allotted to gluten development
§In order to keep all other variables minimally compromised I will make the dough §As each batch of dough is finished, each group will “handle” the dough an allotted amount of time
§You will take a quiz first – 10 mins §Your groups have been assigned already §Everyone is required to participate and will complete their own lab report §Yes, you will get to eat your product, but yes, some of them will… well…
§I know have a zero tolerance policy for cell phones §I don’t want to see it at all §This is your warning §You will place it in my hand, or a SAM will be called to escort you to the office §There will not be a discussion
§Not all baked goods benefit from a strong elastic gluten §Great for yeast breads and bagels §Not great for cookies, cakes, and biscuits §For tender preparations, bakers intentionally limit gluten development
§There a number of ingredients by which the baker can control the gluten strength §Type of flour §Oxidizing agents - discourage §Water content of the dough – higher = lesser §Stirring and kneading - encourages §Salt – encourages §Sugar – discourages §Fats and oils - discourage §Acidity of the dough - discourages
§Gas bubbles is what makes cakes and biscuits light and tender § 80% of the volume is air §Can be produced by yeast, or the process of creaming
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