Re: how to prepare a well fermented yogurt at home
yes jhan is right,
i make yogurt almost every other night with a yogurt maker and i absolutely love it! you bring a
quart of milk to just under a boil and then let it cool but no cooler than room temp. i test the milk on my arm like you would a baby's bottle. once it does not burn my skin i know it is cool enough to add the starter - which as jhan said, you take a little bit of the milk out separately and mix the starter into this. then you add that back into the pot and mix all of it together and pour in the yogurt maker. the yogurt maker works the same as the rice cooker (keeps it at a steady/even temp until finished).
once you have a batch of yogurt you can save about a half a cup and use that as your starter for your next batch to save yourself money. but eventually it gets too tart when you keep using the yogurt itself as a starter and then you have to start again with a fresh batch - meaning use a packet of starter again. i have found that it turns into yogurt much faster when using yogurt as a starter then when you use the starter packet so i only cook it for about 4 hrs when i do this. when i do the starter packet i can leave it over night up to about 12 hrs and it does not get to tart. the tarter it is the less lactose (i think but not positive).
i use "yogourmet" starter and it works great. search for it on the web. they have kefir packets and probiotic packets and many other different types. i have used both of those and they both work great. i also add stevia to mine to sweeten it, and sometimes a tiny bit of vanilla extract even though it has some sugars. or i put in hazelnut flavored flaxseed oil which is good for candida.
one important thing you should know when making yogurt - ALWAYS make sure the equipment/dishes you are using to make it are extremely clean. bad bacteria can grow if you don't clean all utensils/pots/yogurtmaker very well beforehand. i actually saw this on the food network - good old alton brown and his scientific cooking style : )
oh and i actually use half and half, not milk because it is lower carb and gets nice and thick. when i use whole milk it is often very soupy/liquidy.