If we are preparing a dry cake mix,

If we are preparing a dry cake mix, we must cut the shortening into the flour, sugar,and other dry ingredients in order to produce a fluffy homogeneous dry mix. We may usea ribbon blender, which is a horizontal trough with one of several types mixing elementsrotating within it. The efficiency of mixing depends on the choice of the mixing element.For mixing solids into liquids to dissolve them, a propeller-type agitator mounted withina stainless steel vat is best. There are a great number of propeller, turbine, and paddletypes available for this kind of mixing. All types of mixers do some work on the materialbeing mixed and produce some increase in temperature. It is often desirable to minimizethis temperature rise. However, mixers are also chosen to do special kinds of work onheavy viscous materials while they are being mixed. These mixers may have arms thatknead dough, or paddles and arms that work butter. These working mixers are designedwith precise geometries to maximize efficiency and minimize energy requirements toachieve the mixing-working operation. Still other mixers are designed to beat air into aproduct while it is being mixed. The mixer-beater found in ice cream freezers is anexample. As the ice cream mix is being frozen within the freezer bowl, the beatingelement, or dasher, turns within the bowl. It not only keeps the freezing mass moving tospeed freezing and make freezing more uniform, but it also beats air into the product togive the desired volume increase, or overrun, necessary for proper texture.