I made a soaker with a bunch of different grains and let it sit for 24 hours in a bowl with hot water to soften it up. The grains will soak up about 75% of the water which will end up making your dough very moist.
45 grams Malted Rye Berries
80 grams Groats
75 grams Soft White Wheat
275 grams Boiling Hot Water
Mix water in a bowl with other ingredients and let sit covered at room temperature for 24 hours.
Starter Build 1
36 grams Seed (Mine is 65% AP Flour Starter)
114 grams European Style Flour (KAF)
45 grams Yeast Water
30 grams Water (85 - 90 degrees F.)
Mix seed with water to break up for a few seconds and then mix in flour until the starter form a smooth dough consistency. Put it in a lightly oiled bowl and loosely cover and leave at room temperature for at least 6-10 hours. The starter should double in volume.
Starter Build 2
150 grams European Style Flour (KAF)
95 grams Yeast Water
Mix the Yeast Water and flour in with the starter from Build 1 for about 30 seconds to a minute until all the ingredients are incorporated. Cover and leave at room temperature for at least 6-10 hours. The starter should double in volume.
425 grams Starter from above (It's possible you could have a little left over from above but I had exactly 425 grams)
100 grams White Rye Flour
100 grams Potato Flour (KAF)
300 grams European Style Flour (KAF)
All of the Soaker from above
325 grams Water (90 degrees F.)
16 grams Sea Salt (or table salt)
22 grams Honey
Prepare the soaker 24 hours before you want to bake the bread. When the soaker is ready, make sure to drain any of the water it has not soaked up.
Next mix the flours together with all the water except for 90 grams for about 1 minute and let it autolyes covered, for 30 minutes in your mixing bowl . After 30 minutes add the levain, honey, salt and the soaker and mixed on speed #1 for 1 minute or by hand until everything starts to come together. Add additional water as needed and mix for 4 additional minutes. Note that this is a very sticky dough so don't be afraid to use all the water but make sure you don't end up with soup.
Since this dough is very wet I put it directly into my oiled dough rising bucket and did a couple of stretch and folds. Rest it in the covered bucket for about 10-15 minutes and do a total of 2-3 additional stretch and folds within 2 hours. After 2 hours and several stretch and folds (I did a total of 3) place the dough in your refrigerator for 12 - 24 hours.
Score the loaves as desired and prepare your oven for baking with steam.
I pre-heat my oven to 505 degrees F. about 30-40 minutes before baking. I add 1 cup of boiling water to a heavy-duty sheet pan on the lowest shelf in my oven and I have 1 oven stone on the top shelf and one above the steam pan.
After placing the loaf in the oven I add the water and lower the temperature to 450 degrees. Since this loaf is so large I had to lower the temperature after 30 minutes to 425 degrees and baked another 35 minutes until it reached an internal temperature of 205 degrees F.
Let the bread cool for at least 2 hours or longer until you try it.