Why wont some cream make butter?

Answer 1

Churning butter Basically you are duplicating the process for making butter yourself. You add energy (work) to the system. This breaks the fat droplet membranes and allows the fat molecules to come together (coalesce). When enough fat comes together, one gets a phase inversion in part of the system, and the fat becomes the continuous phase and the water the discontinuous phase -- and if the fat is a solid fat, one gets a material from milk that we call butter. Butter is over 80% fat with water and solubles making up the rest of the system. The remaining material is then buttermilk. http://www.madsci.org/posts/archives/2006-03/1143829481.Ch.r.html If you whip cream too long, it does not gradually become butter: it happens quite suddenly.

Answer 2

Pure cream will always make butter if processed correctly. Other sorts of cream, such as cream that has been processed and is sold commercially, may have additives or may have undergone treatments that render it unable to convert to butter.

Answer 3

Cream is churned in order to separate the cream into two. One part being solid (which will be the butter), the other buttermilk. The buttermilk is drained off and used for other purposes and the molecules of butter, are then further worked together to make a solid mass i.e. into a block (square or round) of butter. The best butter, is butter with the least amount of water left in the butter. French butter fits this criteria.