Yogurt 2nd Attempt

My second attempt at yogurt:

Ingredients:
Milk:

• Amount: 1/2 Gallon
• Brand: Costco's Kirtland whole milk. 
• Other facts: Homogenized, no rBST, Pasteurized, with Vitamin D3 added

Yogurt Starter:

• Amount: 1/2 Cup
• Brand: Home made from the last batch

Incubator Used:

• Cooler

Steps & Notes:

I followed the same directions as the first time:

1. Heat Milk: I warmed the milk to ~ 195 degrees Fahrenheit. This was a little hotter than the first time.
2. Cool Milk: I only cooled it to 130 degrees, which is on the hot side. I've read people going as cool as 100 degrees.
3. Stir in Starter: I stirred  1/2 cup of starter from the last batch into a separate bowl with a smaller portion of milk to try and get a more even dissolution, I then mixed it in with the rest of the milk. 
4.  Pour into containers: One container had cinnamon sugar on the bottom when I poured the milk in, it turned out pretty well.
5. Incubate: I used the cooler with hot water again, the water was a little warmer than last time too, I think around 130 degrees. We tried different sized containers and continued to experiment with putting some in the water and some above. 
6. Timing: I've been reading about timing for incubation. I guess it only needs to sit until the yogurt 'gels'.  The added time apparently changes the flavor more than the consistency. If I remember correctly, the longer it sits the tangier it tastes. I left this one out a while and it was pretty tangy.

Results:

• Mixed outcome, I think I did everything a little too hot and must have killed some of the starter. It seems the yogurt that was submerged continued to be very liquid and never really gelled. It also tasted fairly sour. The yogurt that was above the water or part in the water kind of worked.
• Taste: Not tart, more sour and tangy
• Consistency: Some turned out really liquid and never gelled. Some gelled and set up okay, but was still tangy.
• Rating: 2 start out of 5

Possible Improvements:

• Don't incubate with such hot water
• Don't heat the milk too hot and let it cool off more.
• Mix in some powdered milk w/milk before heating. This is supposed to thicken the consistency more
• Try a different incubator method.