Homemade yogurt refined

Since my first attempt on doing homemade yogurt, I've got into a habit of making one bottle per week. With practice, the outcome has improved gradually. I think that many of the traditional cooking methods allow for much more flexibility to change than the precision-based scientific method. I took my Iranian friend's yogurt making technique, refined on the ingredients, temperatures and duration. What I've got is a very smooth and thick yogurt. In general, the milder the temperature and the longer the incubation time, the finer yogurt is yielded. After several attempts, I finally discovered how the temperature of incubation directly affects the texture of the yogurt. With a lukewarm temperature, the yogurt has a smoother liquid feel, while a high temperature (one that almost scalds the hand) gives a semi-solid tofu-like curd that is commonly available in the American grocery stores.


Recipe: Homemade yogurt (12 fl oz)


Ingredients:
- 6 fl oz of evaporated milk (mixing half whole and half skim)
- 6 fl oz water
- 16 oz glass bottle
- 1 teaspoon yogurt with active culture (starter)


Procedure
1. Sterilize one glass bottle, and one spoon by boiling in water for 15 minutes.
2. Scald 6 fl oz evaporated milk with equal amount of water in a small pot. Scald on high heat is fine. But it's important to watch and stir continuously. Once the milk start boiling, turn heat down to medium or low and allow to boil for a minute or two. Then pour milk into sterilized bottle and cover container. 
3. Allow the milk to cool to a temperature that is warm and comfortable to the hand. Use the sterilized spoon to scoop in the starter yogurt and stir to mix completely with milk. Replace and tighten bottle lid, and set bottle in a water bath that is just a little warmer than then milk. The water level of the bath should be just above the level of the milk in the bottle. Be careful though not to allow water to get into the bottle. The water should be just a little warmer than the milk bottle, and comfortable to touch. The water bath can be the pot of water previously used to sterilize the bottle. Try keeping the water bath's temperature within this comfortable range of warmth for 24-26 hours. This may require periodic reheating of the water on the stove. Whenever reheating is needed, remove bottle from the water bath first. Stir water in the bath until the desire temperature has been reached uniformly before putting the bottle back in. To keep the water bath warm overnight, cover the pot (with bottle in it) with lid. Wrap pot  top, bottom and all around, with a few kitchen towels. Because the water temperature is only lukewarm, it can keep warm easily overnight. Reheat to desired temperature the next morning. 
4. Wipe bottle dry and keep in fridge when incubation has yielded a yogurt of the desired texture. 


My Persian friends told me some of their ways of using yogurt. I tried it with garlic and paprika powders. It's so good!