Our customers ask whether electric pressure cooker is slower than stove-top pressure cooker.  Someone claimed that stove-top cooker can be 2~3 times faster in reaching working pressure.  This may be possible with a gas-stove.  However the majority of North American families use electric stoves. We decide to run a test on this typical scenario.

Test equipments:

• 

  Instant Pot IP LUX60 at the heating stage

  Instant Pot IP-LUX60: 1000W, 6L inner pot. Plugged-into an electronic power meter (Kill-A-Watt P4400).

• 

  T-Fal Safe 2 on Maytag electric range

  T-Fal Safe 2 Model 3271 stove-top pressure cooker, 6L capacity, which likely has a pressure rating of 11psi.

• Maytag SuperCapacity Plus electric range with glass ceramic cooktop, coil element power rating: 2100W
• Thermoworks Splash-Proof Super-Fast Thermapen, accuracy +/-0.4°C (0.2°F).

Test conditions:

• Fill both Instant Pot and T-Fal with 3 liter tap water at 13.6°C
• Set to cook at full pressure for 10 minutes. The “Manual” mode of Instant Pot was used.

After running multiple tests, the following is the results:

• Instant Pot IP-LUX60 took 23:30 ~ 24:15 (minutes:seconds) to reach working pressure 11.6psi.  Hold pressure for 10 minutes. Total power consumption 0.35~0.36 KWH.
• T-Fal on Maytag electric range took 24:05~24:50 to reach pressure (steam release started leaking steam and rotating).  Afterwards, power was turned down to 30% to maintain the pressure. Total power consumption based on the power rating: 0.945~0.974 KWH.

In conclusion,

• The stove-top T-Fal + Maytag electric range take about 20~30 seconds longer to reach working pressure than Instant Pot IP-LUX60.
• Instant Pot IP-LUX60 uses around 63% less electricity than the T-Fal in this specific test.

There are two possible explanations regarding the electricity consumption:

1. The glass ceramic cooktop reduces heating efficiency. The whole stove was warm and the T-Fal radiated heat along the way. That’s where the energy had gone.
2. 

   Curved 3-ply bottom of Instant Pot stainless steel cooking pot

   Instant Pot has two layers of air insulation, which minimize energy leakage. The bottom of its inner pot is curved inwards which fits tightly on the heating element curved outwards. Thermal conduction is excellent.

When we first designed Instant Pot, the intention is to make it fast in terms of convenience.  A press-a-button set-and-forget smart cooker is our objective.   Now heating efficiency makes Instant Pot faster than stove-tops on an electric range.

Sautéing is a method of cooking food with a small amount of oil or fat at relatively high heat. Food that is sautéed is browned while preserving its texture, moisture and flavor.  A typical use of sautéing is to brown the meat before pressure cooking.

The new Instant Pot IP-LUX60 is equipped with an advanced sautéing/browning function key.  3 levels of temperature can be chosen with the “Adjust” key for best results.

• “Normal”: ~160°C (320°F) for regular browning,
• “More”: ~170°C (338°F) for darker browning,  and
• “Less”: ~105°C (221°F) for light browning.

The “Sauté” function can also be used to thicken the sauce after pressure cooking, by adding starch or simply evaporating liquid. In fact, it can be used for anything related with a sauce pan, e.g warming a canned soup, reheating porridge, etc.

During sautéing, the lid needs to be opened at all time to avoid pressure building up.  If the lid is closed, the display will show a flashing “Lid”.

The procedure of using “Sauté”.

• Press the “Sauté” function key.
• Select a temperature with the “Adjust” key for “Normal”, “More” or “Less”.
• When Instant Pot reaches the given working temperature, it displays “Hot” and you can start sautéing/browning meat.
• One full “Sauté” session will run for 30 minutes. You can cancel it at any time by pressing the “Cancel/Keep Warm” key and continue with a pressure cooking function.

A brief video demo of Instant Pot IP-LUX60 for browning (sautéing) in action.

The hardware design of Instant Pot has matured for many years. Millions of electric pressure cookers of the same design are in use worldwide. However, our design team have been working on improvement to safety and performance for the last 6 months. I’d like to mention two most notable hardware enhancements.

Safety First

The original power cable connector has a flat surface, see image on right. Liquid could drip from the lid or water collector along the cooker housing wall into the connector, which could become a power short-circuit hazard. Although none of such incident happened, our design team added a shield to redirect water away from the connector. This shield protect the power connector from any spilling water. See the new design in the picture on right.

Better Steam Release

The original steam release has a metal cone inside to seal over the steam release pipe on the lid. Metal on metal doesn’t always create a tight seal. There were reports of steam constantly leaking from the steam release. Although the defect rate is very low, at about 0.6%, our design team believed that they can resolve the problem once for all. The solution is to use a silicone rubber cone in the steam release. The silicone rubber cone creates a tight seal over the steam release pipe. This design was shipped with the last container load of Instant Pot IP-CSG60 and we haven’t had any report of leaky steam release.

After a runaway success of our model IP-CSG60/50, we have been looking for design ideas for our new models.  Our source of inspiration came from user feedback.  In general, the vast majority of our customers approves of our design philosophy of “Safe, Convenient and Dependable”.  Instant Pot is about “set and forget” cooking style, leveraging the micro-processor controlled smart cooking programs.

Summarizing the user feedback, we found two areas which need improvement or enhancement.

1. Convenient and intuitive user interface.
2. Versatility of cooking capabilities.

We have taken these two points to heart and implemented them in the design of our new model IP-LUX60/50.  This blog covers how the user interface is improved.  I’ll talk about how the versatility is enhanced in my next blog.

We have a confession to make.  The most support calls we received are questions about the flashing dashes and the marquee symbol (for pre-heating) in IP-CSG60/50.  We decided to use plain English on the display to make the status display intuitive. Due to the limitation of the LED display panel, it’s a small challenge to find the right words.

Now in our new model IP-LUX60/50, the followings are used.

Another improvement to usability is to allow manual changes to all preset cooking time.  Simply, press and hold “+” or “-” to race the number to your desired cooking time. Note this doesn’t apply to the fully automated “Rice” and “Multigrain” programs.

Our users told us that you want more capabilities from Instant Pot, especially the browning and slow cooking.  You may ask how “slow cooking” is compatible with the brand name of “Instant Pot”.

When our design started over 3 years ago, the intent was to create a smart cooking appliance so that cooking process to a user is “instant”, i.e. the press of a button. Of course, being a pressure cooker Instant Pot also speeds up cooking substantially.

To enhance Instant Pot’s versatility in cooking capabilities, we added Sauté/browning with 3 different temperature settings, ranging 105~170° C (221-338°F).  You can use “Adjust” button to choose “Less” for low temperature, “More” for high temperature (close to olive oil smoking point) and “Normal” in between.  Sauté is done with the lid opened. This function can also be used to thicken the sauce after cooking.

Following the same line of reasoning, we added 3 temperature settings for “Slow Cook”, ranging 88-99°C (190-210°F), again adjustable with “Adjust” button.  These correspond to low, normal and high temperature cooking in common slow cookers.

We also extended manual cooking time to 120 minutes to cook tough dry food, e.g. split corns, in one cooking cycle.