This illustrates a step-by-step easy method for culturing Piima and it's Swedish cousin, Fil Mjolk. This is what I do. It works well for me.
1.  Typically piima and fil mjolk are cultured in individual serving glasses. It is cultured on the counter at room temperature. I cover the glass with a paper coffee filter secured with a rubber band.
2. This is a 24 hour culture of fil mjolk. It is fairly soft, not as firm as custard or commercial yogurt with additives. The piima or fil mjolk is "done" when it comes away from the side. 
3. Start the next batch with a spoonful from the old culture. This is a spoonful of piima. I would label the glasses because they are very similar in taste and appearance. 
4.  This is a spoonful of fil mjolk. I would love someone to describe how these two are different. The difference is subtle.
5.  Add milk, stir, cover, and set out on the counter for 24 hours or so. It needs to be still to set up. In fact, after shipping it may take a few batches for it to come out firm.
6.  Piima and fil mjolk are very mild and taste good as it is. It is also very nice to add fruit or a little sugar. I use berries and Splenda often.


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