This is a lovely, rich flavoured bread. I adapted two excellent recipes to develop the recipe - one from the internet (link:https://www.seitanismymotor.com/2010/02/100-percent-rye-bread/ ) and the other from "The Extra Virgin Kitchen" by Susan Jane White. It has a more open texture than is usual for a 100% rye bread. It keeps well, and I think the flavour improves with keeping. Toasting it lightly brings out the flavour and it goes well with soft cheese, air dried ham or smoked salmon. My sourdough starter is 5 years old and is yeasty, not particularly sour-smelling. Unless it is very important to you for it to be 100% rye, without any wheat, you could use any sourdough starter. I find feeding the starter the day before using it, and keeping it at room temperature for several hours on the day, makes the bread lighter. This quantity of ingredients makes 2x1kg(2lb) loaves - I halve them and freeze. Have a go, experiment and enjoy!