Old Finnish specialties; pitkä piimä etc.

[Zoey]

I'm wondering about those old Finnish specialties. Some info, but also questions below. I'd be really happy if people could contribute with their own knowledge.

"Pitkä piimä" (word-to-word translation "long buttermilk") for one, is something I would like to know more about. It is as far as I know pretty much a vanished product... notions of it seem to have disappeared around the time when refridgerators became widely used. Anyone know what this is? Is it just a specially (longer) cured buttermilk, or does it have its own cultures? Can it be made, or has the culture maybe also disappeared since it was made? I have a longer definition for this in the book "Kodin keittiösanakirja" or "Home kitchen thesaurus", from the year 1943 if I recall correctly. But it is in Finnish only.

"Rahka" or "Quark". Is this the same as Carelian "Jamakka" or maybe "Paistettu jamakka"? Rahka has been a way of preserving milk in historic times, and has been used as an ingredient in many desserts, pies etc. It is still used in baking today (only the store-bought equivalent has a taste that can't even compare to the original). A lot of information on "Jamakka" is available in a book written by Carelian exiles in 1946. The book is called "Apposkaalista mantsikkamöllöön" which is really untranslatable (I'll leave the translation as a challenge to the other Finns on this forum).

One internet-based simple Rahka/Quark recipe (not tested):
Pour one liter of milk on an oven pan. Let clabber for two days in warm place. Cut curds. Bake for a couple of hours at 100 Celsius. Drain and discard whey. Press through sieve to soften the texture.

Other specialities:
Leipäjuusto (discussed here: https://cheeseforum.org/forum/index.php/topic,2790.msg22306.html#msg22306 and https://cheeseforum.org/forum/index.php/topic,1745.msg16034.html#msg16034 )
Munajuusto (discussed here: https://cheeseforum.org/forum/index.php/topic,1958.0.html )
Piimäjuusto (similar as munajuusto but without the eggs - basically a fresh cheese made by heating buttermilk to near-boiling temperatures and letting it coagulate - then dry salted and drained in form with mild pressure - the cultures being dead in the resulting cheese)

As you may notice, most of my books are printed before 1950. I wish I could say 1920 instead.