How should chuck roast be grilled to maximize tenderness?

Your best method of making chuck tender is to cook it low and slow, as per traditional barbecue.

The reason for this is that chuck is a relatively tough meat, full of connective tissue (the protein collagen, among others).

By cooking low and slow for a long time, you raise the internal temperature of the meat to about 170 F to 180 F for an extended period, at which temperatures over time, in the presence of moisture (either part of the meat itself, or external) the collagen will convert to gelatin, converting from a touch to a succulent and tender product. This is the principal employed in both braising and barbecue (as opposed to grilling, which is a high heat technique normally).

Note that the collagen to gelatin conversion creates the tenderness, it is not preserving tenderness, since it was not a tender cut to start with.

At this point, since you have already sliced the meat, I believe your best approach would be to create an indirect fire or flame. Place the meat in a disposable pan layered together to minimize drying, away from the fire, and allow to cook slowly for at a low temperature (say 250 F to 300 F air temperature as measured in the grill with its lid on) for several hours, at least about 4 hours and up to 8 to 12 hours, until it is fall apart tender.

You may also do this in the oven rather than on the grill. It will also be amenable to braising techniques, as opposed to dry roasting/barbecuing.

While it is too late for this particular chuck, in the future you may have better success not slicing it prior to barbecuing.

If you are thinking of grilling as a high temperature technique and do not want to do the low and slow methods, I am afraid this will not work out well with chuck. It is naturally not tender, and these high temperature grilling will not facilitate enhancing the tenderness. If you are time constrained, you would be better off freezing your marinated chuck for another time, and cooking something else that does respond well to the fast, intense heat of grilling, like steaks or pork chops.

I know and have read over and over the "correct" method of cooking this type of roast is low and slow (meaning for hours on end) not sliced up and on a grill like I did. Its not a traditional steak cut and its not 'supposed to' be treated that way. If you are looking for the best way to cook this meat, follow all the advice you find online and in the other answers/suggestions here. However, I chose to go against that advice and slice up a chuck roast, tenderize it and marinate it to see if I could cook it like a steak. My results were that you can, and the results were surprisingly good. Your results will vary on the quality of your cut and how you prepare it, but it CAN be done effectively.

Because I had beat and cut the chuck into very thin slices, putting them on the grill on low heat for more then 10 minutes was enough to overcook them. Thankfully I only did a few like that and the rest I grilled like a regular steak for a few minutes a side and they turned out better. I don't believe this had to do particularly with the cut of meat, just the fact that they were so thin already.

It really depends on how you cut your chuck roast, and which muscles it encompassed. You can potentially get chuck steaks, chuck eye steaks, and flat iron steaks out of a chuck roast, chuck steaks being the most common.

Chuck eye steaks are cut from the eye roll. This is a continuation of the muscle from which ribeyes are cut. Chuck eyes can be cooked like ribeyes, and will be perfectly tender at medium rare. Flat irons are tougher, but can also be cooked like regular steaks.

Chuck steaks, on the other hand, would be steaks cut from the rest of the roast. I'm assuming this is what you have. These should really be cooked beyond well done for maximum tenderness. You don't need to render out as much connective tissue as you would if you were making pulled or shredded beef, but you will need to render out enough that your knife can cut through it, and your teeth will be able to properly chew the pieces. With thin pieces, you can fry them in a pan until done, and then optionally finish them in the oven. I would also recommend a marinade to help with moisture retention and tenderization. I prefer somewhat thicker cut steaks, which I will marinate and cook low and slow, then sear at the end. Basically I treat chuck steaks like pork steaks, since they are the same cut of meat, just from different animals.

I have done chuck a number of times on high indirect heat about 400 for 2 hours with great results (this came about by accident because I was cooking other stuff that needed the higher heat I didn't feel like cooking separate) The secret to keeping it moist is to make sure its got plenty of fat, marinate it before hand and baste while cooking.

Disclaimer: I've only cooked chuck roasts low 'n' slow in the oven, not on grill but hopefully something I say will help. During a show on Food Network I heard one of the famous, established chefs say that, with meats that are traditionally done low and slow, you also have the option to go quick on high heat.

If you go one extreme or the other you're ok, but in between is not good. With beef stew meat I experienced what you did: you cook it quick to sear/brown the surface of the meat and get the internal meat cooked just enough that it's safe to eat, and when you sample it at that time it will be very tender and edible. But then if you overcook it for 5-10 minutes past that point, it will start to be tough to eat, until you have it simmering for more than an hour after that, where it is tender in a different fashion.

I agree with the earlier post that the various connective tissues need the low and slow to fully break down so if you're going to just cook fast on high, trim it up more than if you were going to do low and slow. I've seen that done several times on the Food Network competition show called "Chopped" where the competitors are challenged by being given a small amount of time to cook a meat that is traditionally cooked low and slow. They trim it more, maybe tenderize with a mallet and or cut thin (across the grain) and or give it a quick tenderizing marinade with something acidic, and then cook on high heat real fast and leave it medium to medium rare.

I also just saw a barbecue show where 3 chuck roasts were put on the grill. When one of them reached an internal temp of 145, it was taken off to eat. It looked ready. Juicy and tender, like a steak cooked medium. The other two roasts were left on for a couple more hours. During the first hour all 3 were left uncovered to pick up the smokey grill flavor; after the first one was taken off the other two were wrapped in heavy foil to let the meat cook and baste in it's own juices, which of course was collected, saved and used as au jus when the meat was done.

In Philly chuck is frozen and sliced super thin. Fry it up on a flat top griddle with onions and cheese and accompanied Ameroso rolls for proper cheesesteaks.