Wartime Wednesdays: Butterscotch.
When sugar and a liquid are boiled together, a sirup is formed which grows thicker as the boiling continues. The thickness of the sirup determines the general type of candy that will result.
Testing the Sirup
The simplest and must accurate method of determining whether the sirup is thick enough for your purpose is to measure it's temperature, because the temperature rises steadily as the sirup thickens.
A CANDY THERMOMETER registering up to 350 degrees F. is not expensive, and it will not only give you a higher average of success in candy making but will save you the time and labor that must otherwise be given to testing the sirup. A table giving the various stages of sugar cookery will be found on page 12.
---The Victory Binding of the American Woman's Cook Book, Wartime Edition; published 1943
Such a simple recipe; corn syrup, water, white & brown sugars are stirred, then boiled till 250; butter is added & then...depending on whether you wanted soft or hard candy...cooked a bit longer. I went for hard, so the magic number was 300 degrees F. Remove from heat, add in some vanilla. The recipe wants it poured onto a cold slab; failing to locate one, I used a greased baking dish.
This tastes exactly as it should. A deep, rich, flavor. Took very little time, with fantastic results.