Gjetost (pronounced yay-toast) translates from Norwegian as “goat cheese,” but it is more like fudge or caramel than cheese in both flavor and the process for making it. It is not ripened. It is simply whey that has been boiled and reduced to about 20 percent of its original volume, which makes it incredibly rich.
My first attempt to make gjetost was an icky failure. I wound up with a salty, sweet, grainy goo in the bottom of a pan after 11 hours of simmering whey on the stove. It looked like sand that had sunk to the bottom of a watered-down caramel sauce. No one else would even taste it. In spite of its dreadful appearance, it tasted delicious, and I knew I had to find a better recipe and try again. Because it is extremely rich and you shouldn’t eat too much at one sitting, I make it only when we have company coming.
Whey is the only ingredient you need for making gjetost, and you can use whatever amount you have left over after making cheese. You should use fresh whey, however, or the final product is likely to be too salty. Put the whey on the stove in a heavy-bottomed pot and boil. And boil. And boil. This process will recall making maple syrup for those of you with experience boiling sap. You will be boiling for a few hours. The more surface area in your pot, the faster the whey will boil down, so given a choice between a tall, skinny pot and a wider, more shallow pot, choose the wider pot to boil down the whey faster.
When the whey starts to thicken and is as thick as a runny pudding, I use my stick blender to get rid of its graininess. When the whey is smooth, I place the pot in a sink of cold water to chill it rapidly while I whisk it.
After gjetost has been refrigerated, it will become a semi-solid piece of cheese, which can be sliced for serving.
This is an excerpt from Raising Goats Naturally: The Complete Guide to Milk, Meat, and More, 2nd Revised Edition by Deborah Niemann.