UPDATE: Upon further reflection, I don’t recommend you actually try this hack, but rather follow the Cooking Issues blog if you’re curious how it turns out.
This looks like a great project for getting the most out of your electric pressure cooker. Please pay attention to the warnings, use common sense and safety precautions. This is a potentially dangerous modification which could cause fire, explosions and possibly injury or death.
According to Dave Arnold, head of the French Culinary Institute’s Culinary Technology department, 15 psi is where it’s at for pressure cooking. 15 psi is what most stove-top cookers provide. At 15 psi you can make great stocks, remove the harshness from garlic, and make incredible slow-cooked Hamine eggs.
Unfortunately, the popular Cuisinart electric pressure cooker doesn’t get beyond 9 psi. At 9 psi none of the magic happens. So, Dave decided to overclock the Cuisinart to 15 psi, by adding a pot switch to fake out the temperature sensor.
The Cuisinart has both low and high pressure settings, but unfortunately the manual doesn’t tell you what those settings mean. I needed to figure out the pressures and temperatures myself. I couldn’t find a good way to measure pressure directly without drilling holes in the cooker, so I decided to measure temperature, instead, by inserting a thermocouple into the unit through the vent hole and then sealing it up. I measured a low pressure temperature of 230 F (110 C), corresponding to 6 psi. At high pressure the unit reached 237 F (114 C), corresponding to 9 psi — below the magic 15.
Here is the part where I void my warranty. I flipped the unit over, took out the two screws and popped off the protective plate. The temperature sensor was located on a spring-mounted button in the center of the unit and had two black wires coming out of it. I popped the connector off the circuit board and measured the resistance of the sensor as I changed the temperature with hot water. Boom. It was a simple temperature-dependent resistor (RTD), and the resistance went down as the sensor got hotter.
The temperature was higher than before -244 F (118 C) but not high enough. I cranked the potentiometer to 1500 ohms and got a temperature of 254 F (123 C). I dialed it back to 1270 ohms and got a friendly 249 F (120 C). Close enough for me.
With the modifications I made, the Cuisinart might be my go-to pressure cooker… I am unsure how durable the unit will be. Two points of concern: overheating because of my modifications, and the possibility that the insert will get damaged by typical use… the reason electric pressure cookers are set to a low pressure is that they can overheat. Time will tell.