Ditto on decreasing the time in the foil.
After several years of using some form of the 3-2-1 method, I've settled on this.
For baby backs, my basic numbers are 2-1-2
For spares (and by spares, I am refering to St. Louis trimmed spares..not a big fan of cooking the whole thing), my basic numbers are 3-1-2
The longer the ribs spend in the foil, the softer they become, but also the smoke flavor begins to wash out a bit.
I want the cleanest looking/smelling smoke right around 225 for the first time period. I don't open the smoker to look at them at all. A friend of mine says "If you're looking, you aren't cooking". Good advice.
I don't even care about pull back during the first timeframe. All I'm trying to do is get the cooking started and the smoke flavor deep inside.
For the second time period, I do two things:
1. Wrap in foil with apple juice and a little more rub - double wrapped in heavy duty foil (If I am cooking for a large number.. more than half a dozen or so slabs.. I'll put the ribs in one (or more)of those disposable foil half pans and seal tightly with foil) I also like to cut into my final portion size before foiling. It makes them easier to handle after comnig out of the foil. My normal method call for cutting the slabs down into thirds.. or 4 bone portions. For competitions, I'll leave them whole because they look better in presentation.. but for parties/dinners.. I portion now.
2. While in foil, I will normally crank up the heat a bit. You really only need to get up over 210-215 or so to boil the brazing juices a bit. but I usually have a little barky wood that I need to burn up, so I toss it in and crank it up to 300 for a spell. At this point I don't care what the smoke looks or smells like because the ribs are protected.
By the third time period, the temp has cooled back down and the smoke has cleared, so I take the ribs out of the foil and layer on the first bit of sauce and let the ribs firm up, take in some smoke and cook in the first layer of sauce. After about an hour, I'll look at the ribs. At this point, I will add amother layer of sauce. If they need a little more cook time, I'll leave them in the smoker.. if not, they come out of the smoker and get put in a pan to hold them, get covered with foil are rest until eating time. They will hold temperature for awhile in a cooler.. if they need to hold longer, I will put them in a hot box, or back in the smoker and let the smoker temp drop to 150-165.
I use this method for both competition and/or catering/gatherings and it always turns out just right.
Everybody likes a slightly different version of "falling off the bone", but since I like to consider even my catering gigs practice for competitions, I always shoot for KCBS standards with respect to doneness.
Happy cooking all!