experimenting with an Instant Pot 3qt mini
I mentioned before that I was going to experiment with the smallest of the Instant Pot line.
I am mainly interested in
- whether or not my system will run it (it’s not set up for big loads)
- will the IP survive on MSW inverter (we know it will run on MSW thanks to YT videos)
- whether the timer will be affected by MSW
- and how energy use compares to what I see in the crockpot.
experiment 1: drumsticks and potatoes
Crockpot target: 190w x 5 hours = 950Wh
I got a package of 9 “Jamaican jerk” drumsticks on managers special. This first batch:
1c water for pressurization
5 drumsticks
3 potatoes, cut up
meat/stew preset (35mins at high pressure, 10.1 psi)
natural release
This was probably a bit too big for the cooker but I forged ahead. I plugged the IP into the kill-a-watt. Here’s what we learned
turned on
The IP pulled <2w while just sitting there, but at an insanely low power factor (0.06). When I switched over to VA it showed ~25w. This is a bit troubling, as it sugggests 23w of heat is being dissipated in the electronics. I haven’t heard of any failures on MSW so maybe the electronics are already heat-rated from being adjacent to the cookpot.
pressurizing
This and saute should be when the IP pulls the most wattage. The 3qt is rated at 700w. During my experiments I saw ~560w. I don’t know if it’s a safety margin1, a function of being on MSW, or a function of being on a cheap MSW without voltage correction. This one sags to about 107v under meaningful load, which could explain a bit of drop in the resistance heating wattage:
700w / 120vac x 107vac = ~624w
This fellow thinks that could be it, and he sees about 578w with his.
It took 190Wh to bring the pot to pressure. I wasn’t timing it but I think it took about 20 minutes. During the later stages of pressurization it cycled off about 10% of the time. While running it dropped my bank voltage by ~0.3v. It was done around 10AM so running closer to local solar noon should strain the bank less.
holding pressure
While holding pressure the heat was running about 31% of the time. I thought it would run less, but I suppose the smaller ones have greater relative surface area wicking off heat.
When it was idly holding pressure it consumed 0.3w - 25w, probably running the sensors. It must be running quite close to intended pressure because during another test I interrupted an ON cycle just after kicking in and the pressure pin dropped after about 15 seconds.
It used 60Wh to hold pressure for 35 minutes. It finished and after about 10 minutes pressure dropped enough that the pin released. I timed the timer (?) and running on MSW did not affect the IP’s countdown timer.
The chicken was done, maybe too tender. The potatoes did not disintegrate. Lots of water left in the botom. I might back this off to 30mins and 0.75c water in the future.
comparison with crockpot
- 950Wh 4qt crockpot vs. 250Wh IP.
- 5 hours crockpot vs 1 hour IP
To be fair, the crockpot makes roastier, browned meals (if cooked long enough) and the IP does not. Horses for courses.
experiment 2: reheating leftovers
Crockpot target: 90w x 1hr + 60w x 2 hrs = 310Wh
I had some leftovers in a foil packet. Let’s “microwave” them.
leftovers in foil packet
0.5c water
add water, place packet on trivet
manual pressure cook on HI for 2 mins
natural release
The reduction in water made for much faster pressurization, maybe 5 minutes. The whole thing from start to finish was ~20 mins and resulted in very hot leftovers.
comparison with crockpot
- 310Wh 2qt crockpot2 vs. 30Wh IP
- 3 hours crockpot vs 0.3 hours IP
This one is a real win.
Update: tried this with a bigger, denser lump of lasagna and it was warm all the way through but not piping hot. May try 5-10mins for bigger bricks. Effect on overall Wh should be minor since it’s already at pressure.
experiment 3: more (or fewer) drumsticks
The last of the drumsticks, experimenting with less water
0.75c water for pressurization
5 drumsticks on trivet in foil boat
meat/stew preset (35mins at high pressure)
natural release
I do not have measurements for this run (accidentally turned off inverter during cooking, zeroing out the killawatt) but pressurization with less water and less food mass was noticeably faster.
bonus experiment 4: banana bread
Crockpot target: 90w x 1.5 hours + 60w x 2 hours = = 255Wh
I used my normal banana bread recipe and based time on this recipe
crockpot banana bread recipe above
pour into parchment-lined dog bowl
cover with foil tent
pressure cook HI for 60 minutes per this recipe
Pressurized in 10min, 80Wh. Took another 100Wh to hold pressure for 1 hour. Maybee 1/4c of water left at the end, so the water seems right on the money.
Feels springy/spongey coming out of the IP. Flavor is excellent as usual and there is an surprisingly-acceptable amount of browning. It will sit on a bread cooling rack for a while to dry out.
comparison with crockpot
- 255Wh 2qt crockpot vs. 180Wh IP.
- 3.5 hours crockpot vs 1.5 hours IP
Not a huge difference here, -29.4%.
bonus experiment 5: red beans
Crockpot target: 190w x 5 hours = 950Wh
comparison with crockpot
- 950Wh 4qt crockpot vs. 250Wh IP.
- 5 hours crockpot vs 1 hour IP
overall impression
An Instant Pot can save a lot of time and energy.
OTOH
- it takes a gob of current
- rarely found in thrift stores while crocks are plentiful and cheap
- physically larger than a similar-capacity crockpot
- cannot dry-bake
- will not warm the van much in winter (this is an upside in summer)
DIY stacking pots
Pot-in-Pot (PiP) cooking is popular with IPers. The pressurizing water goes in the bottom and other small pots are placed in it. The banana bread experiment above is PiP.
I looked in thrift stores for something suitable but couldn’t find anything. This set on Amazon looks good but it’s $29. Then I had a brainwave and whipped out the dogbowl oven bowls. Turns out one medium and one small will stack inside the liner with a flat steel saucer between them. Not sure what the saucer was from but it works a treat.
slow cooking
Most folks say IPs aren’t great at slow cooking but I will try anyway. The official vented lid is $15 so I took the liner into a thrift and found a matching vented lid for $1.
I’ll still need the 2qt crock for baking bread and similar, but I’d like to retire the giant 4qt.
update: using HI mode
I reheated some food today so I could see how slow-cook mode works. The IP turns on full-power for ~5 seconds every ~30 seconds, so about a 17% cycle. This was sufficient to visibly simmer the leftovers at 1,700’ ASL. This is an average of ~117w nominal, or observed 94w in my use case.
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