Mix 1 Tbsp. rye flour and 2 Tbsp. room temp/lukewarm water (preferably filtered chlorine-free water) in a small jar or bowl that holds approximately no more than 1 cup. Mix the two ingredients well, incorporating lots of air. Cover the jar or bowl loosely. Place in a warm spot in your kitchen at about 75 degrees Fahrenheit where it can rest undisturbed.
Do nothing. The starter in the making will probably smell a little sweet - some say like honey. But if not, don’t worry.
Now stir in 1 Tbsp. rye flour (no water) into your mixture and stir well, incorporating a lot of air. You may see a few bubbles starting but if not, don’t worry. Re-cover loosely and re-place in its undisturbed warm spot.
Add 2 Tbsp. room temp/lukewarm water and 2 Tbsp. rye flour into your mixture and stir well, incorporating a lot of air. Re-cover loosely and re-place it back in its undisturbed warm spot.
Day 4 1/2
After 8 hours or up to 12 hours later check on your starter. It should be bubbly and foamy. If not, don’t worry. If it has not bubbled up and there is no foam, leave it for another 12 hours. Then repeat Day 4 - which is now Day 5 for you. Check it halfway through after 12 hours on Day 5. At this point, it should be ready. If not, rye grain/rye flour was probably very old. The key to success here is to have fresh rye flour.
If everything has gone well, and you have a thriving starter, you are now ready to make sourdough bread. Using your rye starter, you will first want to make a "sponge" which you will use to make your sourdough bread. I have included this information in the Recipe Notes below along with a recipe for a No-Knead Sourdough Bread.