I lost my mom when I was only 35. This brings back fond memories of my mom's love for rye bread! She would always spread butter on a slice and drizzle honey on it. I, too, acquired her love of this bread!
First of all, in case your wondering, potato water is the water that is left over after boiling potatoes! Dissolve yeast into the potato water.
Mix together all of the dry ingredients EXCEPT 2cups of the white flour. When the yeast is dissolved gradually mix dry ingredients into the potato water and yeast mixture. Gradually add butter. Turn on floured board and knead. Shape into 2 round loaves. Let rise about 1 hour. Just before baking you may brush with beaten egg and milk. Sprinkling additional caraway seeds on top just before baking is optional. (I did not.) Bake 40 to 45 minutes in a 350 degree oven.
Mom and I enjoy this most when the bread is still warm. Spread with soft butter and drizzle honey on a slice and enjoy!