Did my slow cooker malfunction?

I’m a pretty good cook, but yesterday I burned a roast in the slow cooker. How is that even possible? Burning food in a slow cooker?
I was cooking a chuck roast. Set it for 8 hours on slow, was away from home towards the end and came back right about the 8 hour mark. I looked at the meat through the glass lid, saw it looked fine, enjoyed the very nice aroma, and turned the cooker off. Or at least I thought I did. It’s one of those one-button controls where you keep pushing it until you’re at the desired choice. I may have set it to the “high - 4 hours” setting instead of turning it off.
So just a few minutes later – and I mean maybe 2 or 3 minutes – I turn back to the slow cooker and the liquid is at a rapid boil, liquid on the walls of the pot is scorched, the edges of the meat are turning black, and that the sweet aroma has turned to a nasty burned smell. I yanked the power cord out.
The meal was ruined and the house smelled terrible.
So I’m wondering if I accidentally set the device on high and it’s normal for it to heat up that quickly, or do I have a malfunctioning slow cooker that might burn my house down the next time I use it?

Yes, and no. I don’t think it malfunctioned, although you can try another meal and see if Low works as expected, assuming you turn it off and not up to High by accident after 8 hours. Just so you know, my slow cooker set to High gets hot very fast.

It sounds to me like it’s broke, I would not expect a slow cooker even at high, after finished a low cooking session to be able to do that in less then 5 minutes. Even hard to do with a gas stove in that time frame with a full roast in liquid.

However if the liquid was gone, and the roast started to sear to the walls, maybe, but you said it was rapidly boiling so I assumed it was immersed.

Yeah, it shouldn’t boil at high. A nice simmer is as much as you should get. I’d toss it before something more important than a roast gets burned.

Some slow cookers get to 250F or higher on high setting, so boiling is possible. See this thread on another board. It all depends by brand. That said, it seems unusual to me that a slow cooker would get boiling as quickly as in the OP, and I would suspect there being a problem. Should be pretty easy to test, though.

My slow cooker takes forever to come to a boil, even set at high.

I think it’s malfunctioning. And, as with all malfunctioning electrical devices, you should just replace it. Rather than dick around trying to see if it’s, ‘really broken’, by ruining a few more meals. Just to be sure!

You don’t have to prepare another meal to see if it’s actually broken. A jar of oil should do the job to test the temps.

There was plenty of liquid and the roast wasn’t touching the walls of the pot. Probably about 2 inches of liquid with the roast still in the pot.

The rapid temperature change was what really shocked me. Even though the liquid was hot already from the long cook, and even if I turned it on high for a few minutes, I never would have expected it to develop a full boil and burn the meat so thoroughly.

I don’t like questionable electrical items, especially ones intended for being unattended for long periods, so this one is going in the trash. But I might conduct an experiment first, just to see if I can confirm what happened.

You should see if you can find the design temperatures for the different settings on your cooker. I can imagine a scenario for how this happened if the “high” setting is actually set above the boiling point of water.

Keep in mind that your cooker and all the contents were already hot; again if your medium setting (or which ever setting you had it at) was very near but just under boiling point, it wouldn’t have far to go. When you put a pot of cold water on a burner, it takes a fair bit of time to get it up to boiling point… but if you start with water say 5 degrees from boiling, it can indeed happen within seconds with a big increase in temp coming from turning it up to the max.

Also you may not have had that much actual water left in the 2" of liquid; it would have consisted of fats and other meat juices plus fluids from anything else you added. Once you evaporate most or all of the water out the temperature can jump fast and that thick mixture of food residues can burn pretty easy.

It’s easy for even experienced cooks to mess up the timing of cooking meat to the desired “doneness”… it can often get over cooked with only 20-30 extra seconds exposure to a powerful heat source. If your roast was just-right and already at or near well-done, then a few extra minutes on a much higher setting could actually have had the effect you noticed and you cooker may be fine.

Good explanation re the oil. There was no water at all in the pot. The recipe called for no water and a stick of butter, so it was just the butter and juices/oils from the meat.

But also, this meat was way past done after whatever happened. The entire outside edge of the roast was black and hard. Only the very middle of this flat roast was at all edible, and it had the taste of scorched oil.

Planning to test it tonight when I can stand by with a fire extinguisher. I’ll report back.

Conduct possible experiment outside of house. Just a suggestion.

Or your 2-3 minutes turned into my wife’s 2-3 minutes which are actually closer to 20-30 minutes. It’s hard to thoroughly burn a cooked roast to the degree you stated on the grill if you stick it in the coals in that short amount of time!

Something odd is going on. I kinda wonder if the roast was wrecked before you got home. How good of a look did you really get at it?

I understand that something (say, water) can go from simmering to roaring boil very quickly if you crank up the heat on the stove, in just a few minutes, but this is different.
On a slow cooker, when you turn it up, the heat has to go through the steel case, a layer of air, a half inch of stoneware and then it can heat up the food. Turning it from low to high, it’s going to take a lot longer than 3 minutes to turn a well cooked meal into a charred, dry boiled mess.
In fact, I didn’t even realize you could burn food and boil it at the same time, in a slow cooker. That takes some skills.

The results of my very unscientific experiment were anticlimactic. I started with 2 inches of hot water from the tap (didn’t want to fuss with cleaning up oil) and set the Crock-pot on high. (It’s an actual Rival Crock-pot, I realized.) Ninety minutes later the water temp was 197 degrees and I was bored by then so I terminated the experiment. But at least it didn’t burst into flames. Although that would have been much more decisive results to report.

So here’s where we are:

  • I will accept that maybe my perception of the 2-3 minutes was off. But it still wasn’t long. Maybe 5-7 minutes? I don’t think it was longer than that. I’m sure I didn’t leave it for 15 or 20 minutes.
  • The roast definitely was fine when I walked in the door. The house smelled great and I looked closely enough to see that it looked right.
  • Re how long it would take to thoroughly burn a piece of meat even if you put it on charcoal, my description might have been off. It wasn’t burned to a dry, black, crispy char like you’d get on a fire. The outer edges and pretty far into the middle were overcooked to the point that the meat was very firm, chewy, very dark colored, and had a strong taste of charred oil/meat.

It’s entirely possible that I just goofed by setting it on high and being distracted long enough for it to burn, but the results are still surprising. I just never thought it was possible to burn meat in a slow cooker, and certainly not that fast.

Perhaps the lesson here is that an all oil/no water recipe is tricky or dangerous in a slow cooker?

On the off chance that there’s an electrical problem that made the heat flare up really quickly, I’m throwing it out. Can’t risk a house fire just for pot roast.

I’ll give you that since a lot of the liquid was fat, it may have burned quickly when you turned it to high (Rival Crock Pots have elements in the side as well as the bottom, IIRC).
But I’m still going to guess that the roast was over cooked before you got home. I just don’t think you can go from perfectly cooked to inedible in 10 minutes in a crock pot. Low or high, you added 2% to the cooking time. That’s like turning the oven from 400 to 450 and leaving the pizza in for an extra 15 seconds. It’s going to get more done, but it’s not going to be wrecked.

FTR, I wouldn’t throw it out over this. If it really bothers you, maybe plan on cooking the next thing when you’re going to be around all day. Then you can leave it on low, but bump it up to high for a twenty or thirty minutes, 3 or 4 times just to see if anything happens.

Slow cookers are both slow in a time sense, and in an intelligence sense.

Essentially, they’re just low-heat cookers. If you end up with the temp too high, and there’s localized contact with the bottom of the pot without any intervening water, it’s conceivable that you can get burned on stuff and/or sticking. Ours will do that in a few spots just about every time if the recipe’s right- it’ll boil off all the water in a localized area and cook the nearby juice/sauce thick enough that it doesn’t migrate into the hot spot, and then whatever’s in the hot spot wil burn on.

Slow-cookers are really best on LOW, and not used totally unattended. I’m guessing that your meat was pretty much overcooked already, and all you did by putting it on high for a few minutes was to stir up the bad aromas. A slow-cooker can’t really impart that much heat that fast to cause what you’re describing, unless it’s 99% of the way there already.

This is turning into an interesting exercise in memory and our tendency to be certain of things we actually might have wrong.

Okay, I have to concede that I only looked at the roast through the glass cover so I don’t actually know for sure how well done it was. The scorching seems to be the real issue. If that had not happened and the meat was still in the same state of doneness, I would have concluded that it was way overcooked but it still would be edible, just barely. With the scorched oil taste, it wasn’t.

A moment ago I wrote in this response “I’m 100% certain that the oil was not scorched when I got home” because the house smelled of deliciously cooked roast and even as I looked down on the roast, it smelled great up close. But then I erased that line because I realized that maybe, possibly, the oil was scorched already and I didn’t realize it until I lifted the lid and released the terrible odor, and saw that the oil was bubbling and the meat was ruined.

Perhaps I have unfairly maligned by innocent Crock-pot and I need to find a better roast recipe.

Does the cooker have a “sear” setting? High heat for browning the meat before starting the slow cook process, I mean. If it does, and you turned it to that setting by accident, it would explain your results.

Note, I don’t have a slow cooker. But my pressure cooker, which basically just boils the contents (albeit at a temp higher than 212 F) has a sear setting, so I thought I’d ask.

I’ve been a self taught “home chef” since I was a broke college student and have had my share of mishaps. Here some are anecdotes/thoughts:

  • In braises/roasts, burnt taste seems to be prevalent before burnt smell. I’ve cooked dishes that have smelled proper, but upon tasting, have been burnt and scorched to ruins.
  • Braises/roasts release great smells for the entire time through cooking and “maturity”. This can mask the un-great smells of burning, at least initially, since there is a disproportionately high amount of great aromas relative to burnt aromas.
  • Burning is initiated on the side that contacts the hottest point (duh), almost always the bottom (also duh).
  • High viscosity braising liquids (eg. tomato based, reductions, extremely sweet/syrupy, etc.) burn faster due to their impaired ability to transfer heat away from the hottest point of the cooking surface. They also seem to readily mask the smell of burning (perhaps it inhibits the burnt molecules from traveling to the surface, or has different characteristics of boiling, resulting in less burnt molecules in the air).
  • Agitation reduces the chance of burning in unburnt foods, but encourages the release of burnt aromas in already burnt foods.
  • My crock pot will readily boil broths at the High setting.

My guess is also that the food was burnt/scorched shortly before you returned home. When you first left the house, the water-based juices in the meat supported boiling, which helped to suppress the temperature in the pot. As the butter and rendered fat/connective tissue formed a thick sauce, it created a great aroma that could be sensed before you even enter the house. Over time, the meat contacting the bottom surface dried out and started to burn. The syrupy braise and lack of agitation kept the burning localized to the bottom. Whatever burnt aromas made it out from under the meat, through the braise, into the steam, out of the lid, and into the house would be overpowered by the existing good aromas. When you returned home, you turned the crock pot on high. This extra “oomph” encouraged a boil of whatever juices were left in the meat. Maybe you even gave it a little stir. Either way, the agitation alerted you to the state of your dish, and alas, dinner was ruined.

Iceiso, I believe you have it. That explains it all.