Hi, boys and girls. Have you ever put 1/2 pint of whipping cream into a clean mayonaisse jar and shaken it for a few minutes? If you do (and I’ve done it in my classroom many times) after a while it turns into butter. It’s the same thing as churning it, I presume. But I don’t really understand the physics or chemistry of it. I believe what I’m doing is agitating the fat globule and causing them to aggregate, but I’m not really positive. What’s the straight dope? How does churning cream turn it into butter?
Yes, you are in fact agitating the fat globules and causing them to stick together, in larger and larger clumps.
Do you need a cite or can you take my word for it?
From this site on butter manufacture I gather that butterfat has a tendency to adhere to other butterfat. Churning just gives the accumlating globules more opportunity to encounter other globules. You must realize, of course, that this is just a WAG.
duck - I always take your word for it. thanks. C.
Does it turn yelllow by itself too?
No. Thats a dye or food coloring.
I remember being told that in summer when cows are on grass it is naturally yellow. In winter it has to be colored.
I’ve made butter from store-bought whipping cream, and it butter was much more yellow than the original cream, but not nearly as yellow as store-bought butter. WAG: I wouldn’t be suprised if they dye the commercial butter in order to force different batches to have similar color. If one batch was as white as lard, while another batch was distinctly yellow, would customers complain? And what if a white batch was dumped into the packing machinery which had just processed a yellow batch. The blocks of white butter would be full of yellow clumps. Better to just dye it all so people are none the wiser.
PS, compared to home made butter, store-bought butter tastes terrible. It has a “stale vegetable oil” flavor. (Or we could say that store-bought butter tastes normal, while homemade butter tastes extremely sweet with complex fragrant overtones.)
To make your own butter, just dump some cream in a blender or cuisinart and run it for a couple of minutes. First you get whipped cream, then it turns into dense yellowish whipped cream with yellow speckles, then it becomes a single hugegreasy lump with a quantity of milky fluid left over. Use it as-is, but if you don’t use it up within a couple of days it goes rancid. If you want to store it for many days, you have to mash it with a spoon for about fifteen minutes to squeeze all the bubbles of “whey” fluid out of it.
Actually, I saw Emeril making butter on FoodTV the other night; he made it in a jar (blender jar? shaking? didn’t see that part), poured off the buttermilk, and dumped the fresh butter into a bowl of ice-cold water. This leached out the additional buttermilk as well as some of the milk solids.
He then proceeded to make yummy things with lots of butter. [sub]As opposed to the rest of his cooking, 'tag?[/sub]
That’s cool. How does that work?
Umm, 'cause buttermilk and milk solids are hydrophilic, and butter isn’t. The butter floats on top, like any other oil, and the rest just diffuses out like, well, milk.
I should add that the butter was still in little freshly-churned lumps.
Doh! didn’t read carefully enough. I thought it just said “ice”. I was wondering why sitting a lump of butter on top of ice would do anything…