Day 1: Add 60 g of rye flour, and 60 g of water to your mason jar (or other jar). Mix to combine, you should have a thick consistency. Cover loosely with a cloth and allow it to rest in a warm spot for 24 hours.
Day 2: Check for bubbles. At this stage you may not see anything, or only small pinprick sized dots. Bubbles indicate that the fermentation process has begun. Allow it to rest for another 24 hours.
Day 3: Now is the time to start the feeding process, even if bubbles are not yet appearing. Remove and discard approximately half of the starter (I just go by eye and don't worry about measuring at this point). The texture should be thick and stretchy like a wet dough. Add 60 g of all-purpose flour (all feedings from this point on will be all-purpose flour, the rye is merely to begin the fermentation) and 60 g of water. Mix until smooth. The texture should be similar to a thick batter. Cover loosely and allow to rest for another 24 hours.
Days 4-6: Repeat the feeding process as described for Day 3. When you mix the batter, add a rubber band to your jar to match the level of your starter. This will assist in seeing the changes in volume as the starter rises. You should begin to see your starter rising and bubbling on the surface, as well as bubbles appearing deeper within the culture. When the starter falls, it is time to feed it again. Once you notice your starter rising to double the feeding volume (the same volume above and below the rubber band) then you are ready to go into the maintenance phase, as well as using your starter for bread making.
Tip: You know that your starter is fully active and ready for baking, when you can add a spoonful to a small cup of water and it floats.