Lately, I've made quite a few batches of my favorite caramel sauce as gifts, so I wanted to share the recipe again, which has been slightly adapted. Here's the new and improved recipe with some tips:
Slightly Salted Caramel Sauce
from Cooks Illustrated
1 cup water
2 cups sugar
1 cup heavy cream
1/2 t vanilla
3 T butter
1-2 t salt
Makes approximately 2 cups of caramel
Put water and sugar in a saucepan, stir, then cover and bring to a boil. Once boiling, uncover and insert a candy thermometer. Continue boiling until the mixture starts to have some color and reaches 300 degrees F. This should take about 15 minutes, but start checking it at 12. Meanwhile, pour the cream in a small saucepan, add the vanilla, and bring to a simmer. Turn off once simmering. Reduce your sugar mixture to medium heat and watch it carefully until it turns an amber color and registers 340 degrees. Honestly, I've even taken it off the heat before then, around 330 degrees, and it turned out fine. It jumps from 330 to 350 quickly, so you're better off on the safe side. And FYI, the longer you cook it, the harder the caramel becomes, so don't wait too long if your temperature isn't climbing fast enough. Once you take it off the heat, add in 1/4 cup of the cream/vanilla mixture. This will bubble like crazy, so don't dump the whole thing in! Continue adding it, being careful of the hot bubbling, until all is added. Stir it until smooth. Add in butter and salt. Taste it and add more salt if you want (or more butter, for that matter...I made one batch with 4 T and it was great!) Adding more butter also will thin the caramel out, so you may prefer that.
*One more thing: make sure your thermometer is deep enough in the mixture. You may find the temp isn't climbing because it isn't getting an accurate reading. You may have to tilt the mixture to double-check the temp.
*I doubled this recipe, and it worked great! Just make sure you use a large pot, not your normal saucepan.
Here's a picture of what "amber" should look like: