The Cycle and the Centrifuge

All those posts on old-time dairying practices prompted more than a few “I remember when…” comments from readers. Here’s a great one from from frequent contributor Sally C.:

Your posts have reminded me of Aunt Della — she sold her extra eggs to the egg guy (we had to candle them to make sure they weren’t fertilized) and her milk to the milk man. She had 6 milk cows (which we milked every morning and evening) and she would take the buckets of milk down in the basement to her old separator. The cream would rise to a container on the top. She would keep a pitcher of cream and a larger pitcher of milk for her own use and put the rest in big metal milk containers that the milkman picked up. I can remember them sitting by the gate until the milkman arrived to pick them up. So, yes, they probably got pretty warm by the time he arrived. I have to think that in the ’60s he probably had a refrigerated truck though…I also remember the taste of “fresh” milk – and I did NOT like it! Even cold, it tasted… weird. Grandma liked it straight from the cow. Yuck! Probably because of the buttermilk in it. I don’t like buttermilk today – even the smell. LOL

Now that I think about it.. what the hell WAS that separator? Why did she do that? Was she “pasturizing” it (to a degree)? I can picture it in my mind. It wasn’t really big. It had a large tub on the bottom and a smaller tub on the top and it made lots of noise when it ran. Grandma would pour the milk from her bucket into the small container on the top. She’s the one who called it a separator. I wonder how it could separate the cream from the milk? Was a centrifuge? Or, is my memory faulty…. hard to say.

Indeed grandma’s machine was a centrifuge (but almost certainly not a Pasteurizer). As you point out they consisted of a tub within a tub. When a motor was activated, the interior tub began to spin, the effect being that heavier water droplets were spun out to the outside tub while the lighter fat droplets remained in the inner one. Modern creameries still rely on industrial-scale versions of this technology, which was perfected by a Danish engineer by the name of Mikael Pedersen in 1885 (Pederson was the holder of a variety of patents for various types of dairy and agricultural machinery, as well as one for a very unusual bicycle with a hammock-like seat, which he invented in England in 1894).