En gros on prend un litre de lait battu limite périmé que l'on tape dans un four chauffé à 200°C, mais éteint, et on laisse reposer une nuit ou 12h.
Puis on égoutte et on remue de temps en temps.
En gros hein, si j'ai bien tout compris

Re: Skyr
We use Buttermilk all the time... so easy! When you buy the buttermilk, it is OK to choose one with an older best before date, at least that?s what my elderly Icelandic friend tells me.
You will yield 1/2 of the amount you start with.
Preheat oven to 200 deg. C
Open the top of a 1 liter container of buttermilk.
Stand it on a pie plate or pan.
You can make it with a 2 liter container also or 2 - 1 liter containers of buttermilk.
When the oven reaches the 200°C, turn the oven off.
Place the buttermilk/pan into the oven (you may need to take the top rack out to have enough room).
Let sit overnight or at least 12 hrs with the oven light ON!
To drain, prepare a double thickness of cheesecloth or a thin clean cloth and set into a large sieve over a larger high sided bowl...clothespins help hold it in place.
Pour the clotted buttermilk into the cloth and allow to drain.
Stir with soft spatula every so often and drain the liquid if it touches the bottom of the sieve. This process will take more than an hour, depending on the amount, so be patient.
When all is drained, place the skyr into a bowl and gently blend in 2-3 tbsp white granulated sugar with a wire whisk or hand-held electric mixer set on LOW. You will notice that the skyr becomes shiny. Taste some with the tip of your finger for sweetness. Skyr should be tangy yet slightly sweet.
Enjoy! Delicious with lingon berries, your favorite fruit, granola, maple syrup or simple cream.
Christine, Vancouver
P.S. On my way to Iceland in early May and will be enjoying plenty of skyr when there!