Commercial cream (i.e. the cream you buy in your grocery shop) is homogenized. As a consequence of that, butterfat (aka milk fat) is not easily split from the cream, which of course is a must to be be able to make butterfat (out of the homogenized cream). As a comparison, the fat floats to the top by itself in farm-fresh milk.
In accordance to the Modernist Cuisine cookbook, the solution to this problem is to add 1% Locust Bean Gum (LBG) in proportion to the cream used.
- Add 1% LBG to the cream (choose high-fat cream)
- Warm the cream (with the LBG) to 30 to 40 degrees celsius
- I centrifuged the mixture for one hour at 5250 g and refrigeration set to 5 degrees celsius
- If you do not have a chilled centrifuge (as I used) you need to chill the bottles to solidify the fat
- Make a hole in the butterfat (in the bottles) and pour out the liquid (below the fat)
- Either warm the bottles to melt the butterfat to be able to pour it out or (as I did) carve it out
- Add salt to taste
- Refrigerate until use
The butterfat taste from this procedure is more sweet in comparison to the commercial butterfat that I usually frequent. One reason is that Swedish butterfat (that I am most used to) has lactic acid bacteria added to it which makes it more acidly than most outer butters from around the world.