Put 2 cups of Bulgur wheat in a pot. Add 1/5 cup of rice. Add water, until it passes 2 fingers height over bulgur. The amount of water depends on sucking capacity of bulgur. Boil it.

After start of boiling, wait 3 minutes, then remove from heat.

Use a blanket to wrap the pot. It should be stay at least 5 hours in warm conditions. (Note: You can check the water level 1 hour later. If there is no water, add boiling water. Don't worry about amount of water.)

After 5 hours, pour water out of pot until surface of bulgur. You need some water in it.

By using hand blender, chop bulgur to get soup consistency.

Then, u se a colander and a spoon to filter it. You should remove shells of bulgur for pure soup.

After filtering process, you can add 1 cup of boza or natural yeast.

If you want a taste in boza, you can add two slices of apple. but first try without apple to get experience.

Keep it in warm conditions to accelerate fermentation process. Process is same as yogurt. Wait 12-15 hours in blanket, until bulgur soup solidify.

Now, it is more rigid and you can store 2 cups of boza to use as a natural yeast. You can keep it inside refrigarator for 1 month.

For rest of the boza, you should add small amount of boiling water to liquefy it.