<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I haven't had the book long so I'm trying a few different things. This week I'm going to foil at 140 degrees until 160 degrees to retain the juice that's released. I'm also considering cooling off the smoker to say 200 degrees, once the meat hits 160 degrees, to prolong the period of time the collagen is breaking down. </div></BLOCKQUOTE>
Are you merely "collecting" the juice for a sauce or trying to retain it to keep the meat moist? I assume you mean the former. Once the fibers are heated and they contract, and they squeeze out their water, it isn't coming back. No amount of mopping, foiling, etc can keep it moist. Your only hope it to get it to tender and hope it was marbled to start with.
A hold is possible, you may want to consider using an insulated box for this. You'll be surprised at how long a roast can stay over 160* in a cooler. I'm keeping therm probes in during my hold and I'm thinking its part of my problem, I held a HH brisket for about an hour and when I sliced it, it was over cooked.
Too much collagen breakdown is not a good thing, butts will be mushy and briskets will end up like pot roast.
since we're deep in the science, I'll toss this out:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Prolonged cooking (e.g., braising) has been used to make tough cuts of meat more palatable since ancient times. Indeed, prolonged cooking can more than double the tenderness of the meat by dissolving all the collagen into gelatin and reducing inter-fiber adhesion to essentially nothing (Davey et al., 1976). At 176°F (80°C), Davey et al. (1976) found that these effects occur within about 12–24 hours with tenderness increasing only slightly when cooked for 50 to 100 hours.
At lower temperatures (120°F/50°C to 150°F/ 65°C), Bouton and Harris (1981) found that tough cuts of beef (from animals 0–4 years old) were the most tender when cooked to between 131°F and 140°F (55°C and 60°C). Cooking the beef for 24 hours at these temperatures significantly increased its tenderness (with shear forces decreasing 26%–72% compared to 1 hour of cooking). This tenderizing is caused by weakening of connective tissue and proteolytic enzymes decreasing myofibrillar tensile strength. Indeed, <span class="ev_code_RED">collagen begins to dissolve into gelatin above 122°F to 131°F</span> (50°C to 55°C) (Neklyudov, 2003; This, 2006). Moreover, the sarcoplasmic protein enzyme collagenase remains active below 140°F (60°C) and can significantly tenderize the meat if held for more than 6 hours (Tornberg, 2005). This is why beef chuck roast cooked in a 131°F–140°F (55°C–60°C) water bath for 24–48 hours has the texture of filet mignon. </div></BLOCKQUOTE>
from:
Douglas Baldwin, A Practical Guide to Sous Vide Cooking