Wednesday, March 14, 2012

Follow up: kitchen science

Sometimes I wonder if doing experiments with the kids has any pay off. Then I saw this in my daughter's writing book. She has just started learning to write last year and I think she is doing a great job!



- Posted using BlogPress from my iPhone

4 comments:

  1. Wow. That's so cool. I keep meaning to pick up some cream so Ada can have a go at this, but not getting round to it.

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  2. I used a one litre bottle to get a good amount. Waffles for dinner tonight!

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  3. That's lovely - there are happy bonding times to be had with kids over food. I don't exactly get what buttermilk is, though. Presumably a bi-product of the butter-making process, but what separates from what?

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  4. The actual explanation is below. The way I explained it to my daughter was that the fat in the cream starts to stick together and the non-fat bit doesn't stick. When you beat a little more the butter sticks more together and the liquid that remains is buttermilk. It is very light (I guess because the fat is out, and lactic acid) and is great in anything that needs to rise (pancakes, bread, cake).


    "When cream is beaten air cells form more slowly partly because of higher viscosity and partly because the presence of fat causes immediate collapse of most of the larger bubbles. If most of the fat is liquid (high temperature) the fat globule membrane is not readily punctured and churning does not occur -at cold temperature where solid fat is present, churning (clumping) of the fat globule takes place. Clumps of globules begin to associate with air bubbles so that a network of air bubbles and fat clumps and globules form entrapping all the liquid and producing a stable foam. If beating continues the fat clumps increase in size until they become too large and too few to enclose the air cells, hence air bubbles coalesce, the foam begins to "leak" and ultimately butter and butter milk remain."

    From http://www.foodsci.uoguelph.ca/dairyedu/butter.html

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