I brought my milk to a boil but I don't have time to let it cool. I don't want to put in the enzymes now because they will die off. Can I let it cool in the fridge and bring it back up to 110 degrees F then add the enzymes? My understanding is that bringing the effects of the boiling will last.
Yes, you will be fine. As stated in this question, the main reason to heat milk for yogurt making is to improve texture. Heating it twice should not be a problem. It would be interesting to know if twice heated milk (heated, cooled, and reheated) has an impact vs. the traditional heating, then adding the culture at the correct temperature. There is also useful information in this question and answer, as I was trying to understand the variables in yogurt making. If you are interested in playing with the texture of your yogurt, you will have more information here than you need! If you don't care so much about dialing that texture in to your liking, and just want any yogurt, your process will certainly work.