I tried something yesterday I have been wanting to try for a long time. I put a 3.5# cheap chuck roast in the crockpot about 1 hour on high and then to low until internal temp hit 130 degrees. I then switched it to warm for about 14 more hours. Every few hours I would check internal temps to make sure they were safe. It seemed to linger around 140 the entire time and it came out a beautiful pink and tender as can be. perfect for roast beef sandwiches.
Did you use any other ingredients in the pot?
I’ve only ever made roast beef using the “sear in a really hot pan on all sides, roast 5 minutes/lb at 500 F, turn off the oven and leave it completely alone for 2 hours” method. I’ve gotten good results with it.
This method here was a low temp long time, meat never exceeded 140 degrees so did not over cook but all the connective tissue that makes chuck roast tough had 14 hours to dissolve. I cooked the roast on the warm setting which is not a cook setting.
I don’t think 14 hours can actually help. I’d bet it was just as good as this after half that time. If I’m wrong, then … I’m wrong. 
It takes at least about 12 hours to start dissolving all the connective tissue on a low temp cook, the real slow cookers are taking from 24 to 36 hours and cooking at 130 degrees. 140 was as low as mine would go, You can cook them faster on higher temps but the meat doesn’t stay pink inside.
You should incorporate a pan searing. You get a lot of flavor and texture from a searing that you won’t get otherwise. You need that Maillard reaction.
The sous vide recipes for chuck roast I see take 24+ hours to do at a hold temperature of about 135. I assume the OP is riffing on this idea, except in a crockpot. The reason to do it this way is for what HoneyBadgerDC said. So, yes, it should make a difference. Chuck roast cooked medium-medium rare is normally very chewy. Usually, what you do with chuck is cook it low and slow for 3 hours or so, but you take its so the internal temp reaches around 195-200 degrees or so. Collagen renders comparatively quickly in the 160-170 degree range. At the low temps of the OP, it takes much, much longer.
Yes I found that trick too. This is more how crockpots used to work, today even on low they will boil the life out of food. To lower the temperature you can put something like a utensil on the bottom raising up the pot a bit, to increase it slightly you can place a towel over the lid.
There was another thread here just a couple of days ago on crockpot cooking on the warm setting but I couldn’t find it. I really wanted to respond to that thread as that is what inspired me to try it. I am tickled pink with the results.
Where did you get ‘a cheap chuck roast’? :eek: Even at Aldi, a little chunk is $15 and cooks down to two appetizer portions.
I find Aldi meats to be more expensive than my usual supermarkets. I can usually find one of them selling chuck roast for about $3-4/lb. Looking at the flyer from Jewel (the biggest local chain, I would think), I see last weekend they had USDA Choice Boneless Beef Chuck Roast at $2.49/lb.
I recently did a pork shoulder roast sous vide for 48 hours (135 IIRC) then an hour in the oven at 300. It was the best pulled pork I’ve ever experienced.
I plan to get one as soon as the dust settles and the better models and values are sorted out. I love rare meat but I hate tough meat.
My brother did a 48-hour home-cured corned beef for St. Patrick’s Day. (That is, the sous vide was 48 hours. The cure was I think 10 days?) That was quite excellent.
Alright, I need to eat this now.