I've been researching recipes for caramels for different chocolates and have been puzzled by an apparent difference in culinary opinions. I know the addition of dairy results in a creamier caramel, but some insist on adding it at the beginning of the cook, and others insist on adding it after caramelization of the sugar. It shouldn't affect the texture, should it? The cream still caramelizes whether it's with or after the sugar caramelizes, so I don't see any tasting difference. Really it comes down to stirring and time management from what I can see. To be honest, I haven't taken the exact recipe and made that single change to find out for myself - I'll report if I get it done this weekend - but I was wondering if any Chocolatelife people had their own theories/preferences. I would appreciate any ideas/opinions/data/speculation, etc....
Caramelization of sugar and of milk are two completely different things. Caramelization of sugar is a breakdown of the sugars, producing several new compounds that produce the brown color and it's flavor. With milk it's a Malliard reaction between the milk proteins and the reducing sugars (glucose, lactose, maltose..... but not sucrose). With milk the flavor and color are controlled by time, temperature, and pH. So even if you cook to the same temperature, but one batch taking longer than the other will give two different color/flavored caramels. Even changes in the water you use can make changes (pH, hardness...)
As far as recipes, there are hundreds. It's all a matter of what you want in color, flavor, and texture. Milk caramels are usually not colored by caramelized sugars as the temperature doesn't get high enough. Sugar will start caramelizing over 300F and developing a nice flavor about 345F. Much over that you start forming compounds (HMF) that give strong bitter notes.
I have tried both methods and there are great recipes for both. I currently use the method that requires you to add all the ingredients (including the cream) at once. I find that you get a more complex flavor with deep dairy notes. Mark explains it really well. The method I use requires a lot more stirring as milk proteins will burn if not stirred frequently. Good luck!