If you don’t know what this is, it’s a traditional dark bread here in Finland (or perhaps in all scandinavia…), made solely out of rye flour and water (and salt). No milk, no added yeast – leavening occurs through natural fermentation process. Don’t know for sure if it should be called rye bread or leaven bread, so let’s try both.
Because there was very little information present on this particular art of baking – I’ll share my experiment with this traditional bread, which I like to  eat alot. I’ve never tried to do it before, as I’ve had illusion that it’s too much of a work and needs unseen university degree in magic to get it going on a modern kitchen (as I didn’t have the old traditional wooden basin, or hundreds of years old sourdough from my ancestors…) For some reason (perhaps others have been as sceptic as I was) there seems to be very little information on how the sourdough should be made from scratch. All the instructions I’ve seen rely on the fact that you’ll have saved some dough from your last patch of bread…
Sourdough:
So I couldn’t find out any exact information on how this should be done, there is lots of mixed opinions [FUD] around the internet on this. I read few posts from different internet forums, digged some information on traditional cooking book and counted 1+1 = 3. This is how the experiment turned out.

• I took a clean (washed it with boiling water) glass pint with ~2dl of boiled and cooled water.
• Crushed one finncrisp into the water (this is the magic ingredient, I don’t think it’s necessary at all, but idea of adding it was in the traditional cooking book. I’ll have try this out without the finncrisp in the future and update this if needed.)
• Added few tablespoons of rye flour and roughly one tablespoon of  milk.  (And for a sake of trying it out I did another identical pint without the milk to see if it would make any difference.)

Sourdough should be quite thin liquid, I added flour very cautiously. Whipped it also well as fermentation needs the air.
I left both pints in a warmish place and covered them with cloth. Whipped them over once a day, after first 24 hours, nothing had happened, but on a second day, I could see some bubbles on both pints and also they smelt a tad sour. Whipped them again, added a bit of flour and left them to ferment further. Third day made the difference. The one with milk had a lesser amount of bubbles and quite nice smell. Another was almost foamy and smelt sharper. I decided the one containing that tad of milk, would be ready and sourdough for my coming up bread. I forgot to took image of this, so no pictures of this.
The sourdough goes dough (or paste:)
And on we go after three days of eager waiting. I took roughly one litre of water (a tad above room temperature). Added the sourdough to it and about 0,5l of rye-flour, mixing and whipping it well, again coming fermentation process needs air, so this is mandatory.  [And in case you had done this before already, now you just take the bit of paste you saved from last time, mix it with the water, and voila. You have sourdough. Add flour and continue.]
After this phase I had quite thin ”rye-porridge” which I left to a warmish place to ferment for a roughly 16 hours.
Sourdough worked as it should and I now had a half a bowl of bubbling porridge. Smell it, it should be nice, fresh and sour-ish. Depending on how well fermented (longer you keep it, the tougher the taste) bread you like, you can keep it in bowl for several days, just remember to add some flour once a day so the process lives on. And also remember to whip it a little while adding flour.

I decided that one day was enough for my taste (and for this test), so at this point (16hrs after mixing sourdough, water and flours) I added roughly 1kg of rye-flour and turned it into very thick brown dough. I read an recommendation that one should mix it with wooden stick or stow and add flour until the stow almost cracks in half. I think this was very correct statement and also on a sidenote: don’t put your hands in there if not necessary… It will be sticky and very messy.

Put a cloth on top of the dough it and let it be leavened for a few hours, it should roughly double in size. At least mine did 😉

Last phase is to turn the dough in to the bread. I made the ”traditional” thin disc-shaped bread out of it.   Remember to save some dough for the next time so you don’t have to do the sourdough from the start again! Readily shaped discs are further leavened for couple of hours in warmish place and under a cloth. I baked the bread in middle section of oven and with 250 degrees (C) temperature – for about 30min. After you take them out of the oven, let them cool under a cloth and I strongly recommend that you cut them while they’re still a tad warm. Failure to follow this last instruction will propably mean that you’ll need a chainsaw to cut the bread :]

And then eat it! It’s just damn good, taste will beat anything you can buy from stores!
Lastly; I take no responsibility on whatever you’ll manage to create following my notes on this experiment. It is your own responsibility to know what you’re doing 🙂
I may add Finnish version of this later on.