We have a recipe for English toffee where on uses 3 sticks of butter, 2 cups of sugar and 1 cup of water. Slowly warm the mixture until 275F and then add some chopped pecans. At 300F, poor out onto a marble slab. We are having trouble with the separation of the fat as the mixture progresses from 275F to 300F. It didn't always happen, but is now happening more frequently. Recently we have been trying this using the control freak with the temp probe (oil) setting. Still separates. I then tried adding a small amount of light corn syrup (failed) or liquid soy lecithin (also failed). Kind of at wits end. The toffee is still tasty enough, but it is much more brittle than when we've had batches that didn't separate. Trying to get our mojo back. Any suggestions on what I need to look at for and what to change? We are about ready to protect our egos and quit trying to make it. Thanks.