A few days ago I dug out my trusty (and very old) Rival Crock-Pot to run a test on how long it would take to cook three common vegetables; notable a carrot, potato and an onion, all of which were cut up into bit sized chunks!
As a part of the test, I wanted to use the ‘low’ setting with just enough water to cover the items being tested. I allowed the Crock-Pot to come up to temperature and then added the aforementioned pieces to it. Well, after more than eight hours, the potato was barely done while both the onion and carrot pieces still needed more time. What? Obviously something was wrong and a little bit of testing told me what it was. The water was only getting to around 135°F and the power consumed was a measly 75 watts! WTF! That’s like trying to cook a meal using a single light bulb – it just doesn’t work!
So, I then got out a newer (and larger) slow cooker also made by Rival and performed the same operation with the same chunks of onion, potato and carrot. This time the ‘low’ setting read 200 watts and after the unit was on for about an hour, I noticed the liquid inside the pot was at a slow simmer. The internal temperature was also at about 178°F! Now that’s what I’m talking about!
At this new and higher operating temperature, I was able to get all three vegetables done to ‘fork tenderness’ in only about 2 1/2 hours! The moral of the story! Make sure your slow cooker is operating at the correct range of temperatures (170F-200F for low and 275F-300f for high) for whatever setting you plan to use. An easy way to get a clue as to what temperature your slow cooker reached is to watch the liquid after it has been on for at least two hours. A slow simmer would be correct for the low setting while more of a slow boil would be about right for the high setting. (Note that opening the cover can set things back by as much as 15 minutes of added cooking time, so try and avoid the temptation).