Skyr, recipe and instructions
Skyr looks like thick yoghurt, and the taste is reminiscent of it. But skyr is actually a type of fresh cheese. Because it is made with skim milk, the fat content is very low, allowing it to be eaten with cream and sugar without too much guilt. It is also an excellent source of calcium. Making it takes time, but it's well worth the effort.
Skyr is not widely available outside Iceland (it is sold in limited amounts in some speciality shops in the USA), which can make it hard to produce in other countries. The reason for this is that in order to make skyr, you need skyr. There is a special bacteria culture that gives skyr its taste and texture, and the best way of getting the bacteria into a new batch is by mixing a portion of prepared skyr into it. Sour cream or buttermilk can be used as a starter in place of skyr, but the taste will be slightly different.
This recipe makes 16 to 20 servings, and can easily be reduced. The skyr can be stored for 4-5 days in a closed container.
10 l skim milk, preferably not pasteurised
8-9 drops OR 1 1/2 tablet rennet
10 g skyr, for the bacteria starter. If not available, use 1 tbs live culture sour cream or buttermilk.
1. Heat the skim milk up to 86-90°C, and cool slowly for about 2 hours, down to 39°C. Stir a little scalded milk into the starter to make a thin paste and mix into the skim milk with the rennet (if you are using dry rennet, dissolve in a little water before adding).
2. Close the cooking pot and wrap in towels or a thick blanket. The milk should curdle over a period of about 5 hours. If it curdles in less than 4 1/2 hours, the curds will be coarse, but if it curdles in more than 5 hours, the skyr will be so thick it will be difficult to strain. When the milk is curdled, cut into the curds with a knife. When you can make a cut which will not close immediately, then you can go on to the next stage.
3. Line a sieve or colander with cheesecloth or a fine linen cloth and pour in the skyr. Tie the ends of the cloth together over the top and hang over a bucket or other container so the whey can drip off. If the skyr-making has been successful, there will be little whey, and it will not float over the curds, but will be visible along the edges of the sieve and in the cuts you made into the surface. You can judge the quality of the skyr from the appearance of the curds when you pour them into the sieve. If the skyr is good, it will crack and fall apart in pieces, but should neither be thin nor lumpy. Do not put a layer thicker than 7-9 cm into the sieve. Keep the sieve in a well ventilated room, with a temperature no higher than 12° and no lower than 0° Celsius. The skyr should be ready to eat in 12-24 hours.
4. The skyr should be firm and look dry when ready. The whey can be used as a drink, to pickle food, or as a replacement for white wine in cooking.
Problems you may encounter, and how to solve them:
If the whey does not leak off the curds or floats over the curds, or the curds do not shrink from the edges of the sieve, then something is wrong. The milk has not been heated to a high enough temperature or has been cooled too quickly, so that the rennet has not had time to work. The more milk you curdle at a time, the relatively less starter and rennet you need. A large container cools slower than a small one, and the effects of starter and rennet last longer.
About the starter:
It is best to use skyr for the starter. If the skyr is sour, it should be mixed into the milk while it is still 80°-90°C. This will remove the sourness. Don't add the rennet until the milk has cooled to approx. 40°C. When the weather is cold, it is best to mix it in when the milk is a little over 40°C (say, 41° or 42°). In cold weather, the milk also needs to be covered more tightly while it curdles. This is especially important if you are making a small portion of skyr.
Eat the skyr as it is, or stir some milk and sugar into it and serve with cream and fruit/berries (bilberries/blueberries are traditional, but crowberries or strawberries are also good). It is also good with müesli and/or brown sugar, honey or maple syrup.
The historical information comes from the teaching leaflet Súrt og Sætt, by Sigríður Sigurðardóttir, published by Byggðasafn Skagfirðinga, 1998.
Recipe translated from Nýja Matreiðslubókin by Halldóra Eggertsdóttir & Sólveig Benediktsdóttir, Reykjavík, MCMLXI; additional information: my grandmother.
In Iceland, you can buy skyr in any supermarket, with a choice of many different flavours, ranging from plain to the traditional bilberry/blueberry, to vanilla, pear, chocolate, etc. You can also get refreshing drinks made with skyr and fruit.