Rice Cookers, Slow Cookers, and Instant Pots: The Inner Pot Problem
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Short answer: with any countertop cooker, the only part that matters is the pot the food sits in, and the machines hide it well. Almost every rice cooker — Zojirushi, Tiger, Cuckoo, the basic Aroma — cooks in a nonstick-coated aluminum pot, which is a Teflon pan that gets scraped with a plastic paddle twice a day; we score it a 2. Most slow cookers cook in a glazed stoneware crock, which is fine from a maker that leach-tests it and a question mark from one that doesn’t. And the Instant Pot, the appliance people most often assume they need to replace, cooks in a bare 18/8 stainless steel pot and is already a 5. If you own one, you may not need anything else on this page. If you want a dedicated rice cooker, buy one with a stainless inner pot; they exist, they’re cheap, and nobody advertises them.
This is a materials review built from the manufacturers’ own spec sheets and material statements, the FDA’s ceramicware rules, and the current Amazon listings, which is how we score everything.
What’s actually in the pot
Nonstick aluminum — Score 2. The default inner pot in nearly every rice cooker sold in America and in most multi-cookers that aren’t an Instant Pot: cast or spun aluminum with a PTFE coating, sometimes branded (“platinum-infused,” “diamond”) to sound like something else. It’s a Teflon pan with a lid, and a rice cooker is hard on it — a starchy paste that has to be scraped off with a paddle, a high-heat crisping cycle on the fancy models, and a dishwasher on the cheap ones. When the coating wears you’re cooking rice, which is acidic enough to matter, on bare aluminum. Zojirushi and Tiger make excellent rice cookers; their pots are still this.
Ceramic nonstick — Score 3. The Ninja Foodi’s pot and a growing number of “PFAS-free” multi-cookers: a sol-gel ceramic coating on aluminum, the same one we score a 3 on Caraway and Our Place. Better than PTFE, still a coating with a two-to-three-year life over aluminum.
Glazed stoneware — Score 4 from a maker that tests it. The classic slow-cooker crock. Stoneware itself is inert; the glaze is where lead and cadmium live in cheap ceramics, and the slow cooker is the worst case for a glaze — eight hours of hot, often acidic food. Crock-Pot’s parent company states that it tests its stoneware for leachable lead and cadmium at accredited labs and that results are far below FDA and California limits, and that it adds no lead to its glazes. That’s a meaningful statement, and it’s why Crock-Pot is a 4, not a 3. It isn’t a published lab report, which is why it isn’t a 5. A crock from a brand that says nothing, or a vintage one with a brown glaze, is a 3 at best — and one that’s chipped or crazed is retired from food.
Unglazed clay — Score 4. VitaClay and Aroma’s clay-pot rice cooker cook in bare fired clay, no glaze at all, which removes the glaze question and leaves the clay body’s own trace metals, which neither maker publishes. Nothing to flake, nothing to wear out, and a different, better texture on rice. A 4 for the same reason as the stoneware: good material, no report.
Stainless steel — Score 5. 18/8 (304) stainless, no coating, nothing to react, dishwasher-safe, lasts forever. The Instant Pot’s inner pot; Aroma’s “Select Stainless” rice cookers; Elite Gourmet’s budget one; the Tatung indirect-heat cookers that Taiwanese households have used for decades. Rice sticks to stainless more than to Teflon — a rinse, a little oil, and a ten-minute rest with the lid on fixes most of it — and that’s the whole trade.
For reference, our scale: 5 is a single inert material (stainless, cast iron, carbon steel, glass); 4 is a coating we’re fine with on a metal we’re fine with, or a tested glaze; 3 is a coating with a shelf life or a transparency gap; 2 is PTFE or aluminum in contact with food; 1 is a hard no.
Keep your Instant Pot
The Instant Pot is the appliance people most often assume belongs on the replace list. It doesn’t; it belongs on the keep list. Every standard Instant Pot — Duo, Duo Plus, Pro, Rio — ships with an 18/8 stainless inner pot with a tri-ply bottom, and that pot cooks rice, beans, stock, yogurt, and a slow-cooked braise on bare steel. The lid has a silicone gasket that never touches food and a float valve; the housing is plastic and steel and never sees the inside. As a material story it’s the cleanest appliance in most kitchens.
Two cautions. Instant Pot sells a ceramic-nonstick inner pot as an accessory and bundles it with a few models; it’s a 3, and you can swap the stainless one back in. And the “slow cook” setting on an Instant Pot runs a little cooler than a dedicated crock on high, so use it on “more” and give it an extra hour. If you own an Instant Pot with the steel pot, buy a second steel pot so one can be in the fridge while the other cooks, and skip the rest of this page.
The rice cooker question
If you cook rice every day and want a machine that does only that, you don’t have to accept Teflon. Aroma makes a line it calls Select Stainless — a plain pot-style cooker with an uncoated 304 stainless bowl — in small and large sizes for a fraction of what a Zojirushi costs. Elite Gourmet makes a six-cup version. Neither has fuzzy logic or a pressure setting; they boil, they switch to warm, and the rice is fine. If you want the Japanese-style precision, the honest answer is that the top-tier makers haven’t put stainless in their pots yet, and the Instant Pot’s rice program gets you most of the way there on steel.
One more thing about rice, since we’re here: the material risk in rice is the arsenic in the rice, not the pot. Rinsing well and cooking in extra water that you drain (the pasta method) cuts inorganic arsenic substantially, according to the FDA’s own testing; a rice cooker’s fixed-water method doesn’t. If arsenic is your concern, that’s the lever.
The slow cooker question
The crock is the question, and the answer depends on who made it. A current Crock-Pot, with its stated leach testing and no added lead, is a 4 we’re comfortable with; use it, don’t cook in it if it’s chipped, and don’t buy a vintage one for food. A crock from an unnamed maker is a 3. If you’d rather not think about glaze at all, you have three routes: the Instant Pot’s slow-cook mode on a stainless pot (a 5); a VitaClay unglazed-clay cooker (a 4, and a lovely one); or a Dutch oven in a 250°F oven, which is what a slow cooker is imitating and what we’d do with a Lodge anyway.
Skip the multi-cookers that aren’t Instant Pots without checking the pot: the Crock-Pot Express, the Cuisinart and Breville multi-cookers, and most air-fryer-pressure-cooker hybrids ship with nonstick-coated pots, and the marketing won’t tell you.
What we’d buy
Instant Pot Duo 6-Quart, 7-in-1 — Score 5
Why it’s here: The appliance that replaces a rice cooker, a slow cooker, and a yogurt maker on an 18/8 stainless pot with a tri-ply base. If you’re buying one countertop cooker, this is it, and if you own one, you’re done.
Instant Pot Stainless Steel Inner Pot, 6-Quart — Score 5
Why it’s here: A second 304 stainless liner so one lives in the fridge with leftovers while the other cooks — and the replacement for the ceramic-nonstick pot if your model came with one.
Aroma Select Stainless Rice Cooker, 3-Cup Uncooked — Score 5
Why it’s here: The rice cooker with the uncoated 304 stainless bowl that Aroma barely advertises. Small, simple, cheap; boils and holds. The answer for one or two people who cook rice daily and don’t want Teflon in it.
Aroma Select Stainless Pot-Style Rice Cooker, 14-Cup Cooked — Score 5
Why it’s here: The family-size version with the same uncoated stainless pot and a steam tray. No fuzzy logic, no pressure, no coating.
Elite Gourmet 6-Cup Rice Cooker with Stainless Inner Pot — Score 5
Why it’s here: The budget stainless rice cooker. Single switch, stainless bowl, glass lid. Costs about what a replacement Teflon pot does.
Crock-Pot 7-Quart Manual Slow Cooker — Score 4
Why it’s here: The classic, with stoneware its maker says it leach-tests below FDA and California limits and glazes without added lead. A 4 because that’s a statement, not a posted report. Buy new, keep it unchipped, and it’s a fine pot for a Sunday braise.
Aroma Professional Rice Cooker with Purple Clay Pot — Score 4
Why it’s here: Unglazed clay inner pot, no coating, and rice with a texture stainless can’t match. A 4 because the clay body’s own metals aren’t published. The one to buy if you want the rice cooker to be the pretty part of the counter.
Skip: any rice cooker or multi-cooker with a “nonstick” inner pot, however it’s branded — that’s PTFE on aluminum; the Instant Pot ceramic-coated pot as your only pot; vintage slow cookers with brown or speckled glaze; any crock that’s chipped or crazed; and “stainless steel” cookers where the steel is the shell and the pot is still coated (read the pot line in the specs, not the headline).
If you already own a nonstick rice cooker
Use a wooden or silicone paddle, hand wash, keep it off the crisp setting, and replace the pot — not the machine — when the coating scratches or dulls; many makers sell a replacement bowl, and for a few models a stainless one from a third party fits. Or run rice in the Instant Pot you already have and retire the rice cooker to the closet.
What would change our mind
Zojirushi or Tiger putting an uncoated stainless or clay pot in a fuzzy-logic cooker would be the product this category is missing; we’d move it to the top of this page the week it shipped. And Crock-Pot posting its leach-test numbers, the way Caraway posts its pan reports, would make the classic crock a 5.
Frequently asked
Is the Instant Pot inner pot safe?
Yes: 18/8 stainless steel, no coating, a 5. It’s the reason the Instant Pot is the cooker we’d keep.
Are rice cooker inner pots toxic?
Most are PTFE-coated aluminum — Teflon — and we score them a 2 for wear and for the aluminum underneath. Stainless and clay inner pots exist and are a 5 and a 4.
Do slow cookers leach lead?
A modern crock from a maker that leach-tests (Crock-Pot says it does) shouldn’t. Vintage crocks, chipped crocks, and unnamed imports are the ones to worry about.
Is Zojirushi non-toxic?
The machine is excellent and the pot is nonstick-coated aluminum, which is the same 2 as every other coated pot. Treat it gently and replace the bowl when it wears.
Can I cook rice in a stainless steel pot without it sticking?
Rinse the rice, add a teaspoon of oil, and let it rest ten minutes off the heat with the lid on before you fluff it. It sticks less than you’d fear and cleans up with a soak.
Is the Ninja Foodi non-toxic?
Its pot is ceramic-coated aluminum: no PTFE, a 3, and it’ll wear like every ceramic coating.
The bottom line
The pot is the product. An Instant Pot with its stainless liner is a 5 and does everything the other two appliances do; an Aroma or Elite Gourmet rice cooker with a stainless bowl is a 5 for people who want a dedicated one; a current Crock-Pot is a 4 you can live with, and unglazed clay is a 4 that cooks beautifully. The Teflon bowl in the expensive rice cooker is the thing to stop scraping.
Scores last reviewed September 2026. How we score.
