- 1 gallon non-fat milk, pasteurized (not ultra-pasteurized)but not homogenized
- 1 (5 1/2-ounce) container Siggi’s plain or vanilla skyr*
- 7 drops liquid animal rennet, or 4 drops liquid vegetable rennet
- 1/4 cup warm, non-chlorinated water
- A reliable digital thermometer
- A fine-mesh nylon vegetable bag or cheesecloth for draining the curds
* Available at Whole Foods, Fresh Market, Haggen’s and specialty food stores. Skyr was introduced to America in 2005 by enterprising Icelandic expatriate Siggi Hlmarsson under the brand name of “Siggi’s Icelandic Style Skyr.”
Skyr—pronounced “skeer”—is a traditional Icelandic “yogurt” that has been made since the 9th century Viking era. It is technically classified as a cheese because it contains rennet, a substance used in curdling milk when making cheese, but is considered a yogurt because of its structure and texture.
Bring the milk to the scalding point. Pour the milk in a heavy-bottomed pot and bring the milk to a slow and steady simmer over a medium-high burner, heating it until it reaches the scalding point, which is between 185 and 190 F; this should take about 15 to 20 minutes. Stir frequently to prevent scalding.
If toward the very end of the heating process you notice that the milk at the bottom of the pot has begun to scald (seems like it is starting to stick), reduce the heat to medium-low, and stop stirring. A small bit of scalding is okay, but you don’t want to release the scalded bits into the mixture.
Turn the burner off immediately when the milk reaches the scalding point. Remove the pot from the burner and allow it to cool to 110 F.
Scoop out the container of skyr into a bowl. Once the milk has cooled down, combine 1 cup of the cooled milk with the skyr, then return the mixture to the pot, stirring to incorporate.
Next, whisk the liquid rennet into the warm water, then stir this mixture immediately into the milk (the rennet will lose its effectiveness if prepared more than 30 minutes before using).
Cover the pot with a thick towel and place in a warm, draft-free spot, such as the oven (not turned on) or an insulated cooler, for 12 hours.
The curds should have separated from the whey overnight—what you need to create the skyr are just the curds. Spoon the curds into a fine-meshed bag or a double-layer of cheesecloth. Suspend the bag over a dripping tray in a cool room, or place the bag over a colander set over a bowl in the refrigerator, and allow the remaining whey to drain until the skyr is thick.
Your skyr will keep for three or four weeks, covered, in the refrigerator. To serve as breakfast or a snack, top with milk, fresh berries, and sugar or honey to taste.