Kansas City Ribs are covered in a thick, sweet rub that usually contains brown sugar. Memphis Style Ribs have a spicier rub but use little or no sugar. These are reflections of the styles and preferences for barbecue ribs that have developed in these regions. Kansas City ribs are served with a thick sweet barbecue sauce, while Memphis barbecue ribs are served dry.
Finding the right barbecue rub for you isn't all that hard. Start with something simple. Do you want sweet, spicy or savory? Now look through various rub recipes for something simple. The best rubs start with just a couple of ingredients and build up from there. Once you get the basics down, you can experiment until you have the barbecue rub that is to your liking.
There are a couple of things you need to know before you start finding your perfect BBQ rib rub. First of all, people will tell you that salt will dry out the meat and prevent browning. Oddly enough most rubs and spice mixtures purchased in the store contain salt. The truth is that you can dry meat by letting it sit in a large pile of salt for many days. However, a light sprinkling of salt on the surface of meat actually draws the flavor of the rub into the meat much more than the salt draws out the moisture. There is even a school of thought that says to apply salt 24 hours before cooking to allow it to sink all the way in.
When it comes to sugar there are a couple of basic rules you need to remember. First of all, sugar works a lot like salt. It needs moisture to dissolve. The moisture on the meat is going to be used to create a syrup-like liquid over the meat. This actually helps hold the herbs and spices in your rub in place. The other rule is the big one. Sugar burns at 265 degrees F. (130 C.). So, if you heat your sugar rubbed ribs to temperatures above this for a long period of time the sugar will burn. However, the sugar in the rub will be mixed with other things like water (from the meat) and salt (from the meat and/or rub). This will slow down the rate at which the sugar burns. You can reach higher temperatures but only for a short period of time. This will allow you to slow cook your ribs on the grill or smoker, then increase the temperature to caramelize the sugar at the end of cooking to create a nice crust on the surface.