general recipe:

50 g preferment    (this must be flour only if water is listed below)

4 g yeast

8 g salt

400 g spelt flour

25 g rye

25 g bread improver  (yuck)

15 g butter 

390 cc water (preferment included). volume measurement...  change to 390g water on scales.

78% hydration dough weighing total of 817g     

 What are you looking for, Remco?  A method to work these ingredients?  

I vote for Janet's suggestions, very thought out.  I might switch some of the spelt for einkorn and up the rye.