Written by Lara Yehia. Lara researches home and kitchen products for Cupindy.
Published November 2026 · Last reviewed 4 Nov 2026 · Cupindy is not affiliated with any brand on this page.
The short answer
Get a narrow-mouth vacuum bottle for coffee and a wide-mouth food jar for hot food like soup. Then check the washing rule, because the makers disagree: Thermos says top rack only, Zojirushi says hand wash only, and Stanley says to check the bottom of the product. Clean the gasket every time.
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Our quick picks
For coffee
Stanley Classic Vacuum Bottle, 1.1 qt
Stanley rates it at 24 hours hot. The insulated lid doubles as a cup, the stopper twists to pour, and Stanley says it is dishwasher safe.
See the Stanley bottle on AmazonThe drawback: it is about 14 inches (36 cm) tall, and Stanley's lifetime warranty does not cover lids or seals.
For hot food
Thermos Stainless King Food Jar, 16 oz
A wide mouth, a steel folding spoon, and Thermos rates it at 9 hours hot and 14 hours cold.
See the Thermos food jar on AmazonThe drawback: top rack only, and it holds heat for fewer hours than the 24 oz version.
Every hold time and washing rule below is the maker's own, read 4 Nov 2026 and cited at the end. None is our own measurement.
The 7 best thermoses at a glance
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| Pick | Type and size | Hold time, per the maker | Washing, per the maker | One drawback | |
|---|---|---|---|---|---|
| Stanley Classic bottle (coffee) | Bottle, 1.1 qt (1 L) | Hot 24 h, cold 24 h | Yes. Check the bottom first. | About 14 in (36 cm) tall. | See it |
| Thermos Stainless King bottle (big batch) | Bottle, 40 oz (1.2 L) | Hot 24 h, cold 24 h | Top rack only, no heated dry. | Stopper material not named. | See it |
| Zojirushi SM-KHE48 (one person) | Sip-from mug, 16 oz (480 ml) | 154°F (68°C) after 6 h | Hand wash only. | No pour cup. | See it |
| Thermos Stainless King food jar 16 oz (hot food) | Jar, 16 oz (473 ml) | Hot 9 h, cold 14 h | Top rack only. | Shorter hold than the 24 oz. | See it |
| Thermos Stainless King food jar 24 oz (big lunch) | Jar with bowl, 24 oz (710 ml) | Hot 14 h, cold 24 h | Top rack only. | Bowl and stopper material not named. | See it |
| Stanley Classic food jar (stew, pasta) | Jar, 24 oz (710 ml) | Hot 15 h, cold 18 h | Yes. Check the bottom first. | 1.4 lb (0.64 kg) empty. | See it |
| Hydro Flask food jar (smaller lunch) | Jar, 20 oz (591 ml) | "For hours" (no figure) | Dishwasher safe. | No hour figure to compare. | See it |
Bottle or food jar?
A thermos is a vacuum-insulated container: two stainless steel walls with the air pumped out of the gap between them. Heat crosses a vacuum very slowly, so hot food stays hot and cold drinks stay cold. Thermos is a brand name, but most people use the word for any vacuum bottle or jar.
The mouth decides the job. A bottle has a narrow neck and a stopper, so it pours cleanly into a cup. A food jar has a wide mouth, so thick soup slides out and a spoon reaches the bottom.
A narrow mouth suits drinks. A wide mouth suits soup and stew.
Use a bottle for coffee, tea, hot water and broth you plan to drink. Use a jar for hot food: chunky soup, chili, stew, pasta and oatmeal.
Why a bigger jar stays hot longer
Thermos rates its 24 oz Stainless King food jar at 14 hours hot and the 16 oz at 9, so the bigger jar is rated 5 hours longer. The plain reason: a bigger jar holds more hot food, and it has less wall per ounce for that heat to leave through.
Size only helps if the jar is full and warm. Thermos says to preheat the jar with boiling water for 5 minutes, then fill it close to the top. As a rule of thumb, a half-full jar cools faster than a full one, so buy the size you will fill.
Best thermos for coffee and hot drinks
For coffee, get a narrow-mouth bottle with a stopper and a cup lid. The Stanley Classic 1.1 qt holds about four 8 oz mugs, Stanley rates it at 24 hours hot, and Stanley says it is dishwasher safe. Drinking alone on a commute? Get the Zojirushi mug instead.
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Coffee pick
Stanley Classic Vacuum Bottle, 1.1 qt
Good for: coffee for two, a long drive or a job site.
Why we picked it: Stanley's spec list gives 24 hours hot and cold. The lid doubles as a cup, the stopper twists to pour, and Stanley says the recycled 18/8 steel body is dishwasher safe.
What to know: the page summary says 28 hours; plan on the spec list's 24. Stanley says the stopper's outer plastic is BPA-free polypropylene.
The drawback: it is about 14 inches (36 cm) tall, and the lifetime warranty does not cover lids, seals or straws.
See the Stanley bottle on Amazon
Big-batch pick
Thermos Stainless King Bottle, 40 oz
Good for: a family road trip, or hot water for tea at a campsite.
Why we picked it: Thermos rates it at up to 24 hours hot and cold, with 18/8 steel walls, a built-in cup lid and a stopper that pours without coming out.
What to know: it weighs 1.6 lb (0.73 kg) empty. Its care guide gives a five-year warranty and rules out fizzy drinks.
The drawback: top rack only, and Thermos says to skip the high-heat drying cycle, which can stress the vacuum seal. Thermos does not say what the stopper or gasket is made of.
See the Thermos 40 oz bottle on Amazon
Commuter pick
Zojirushi SM-KHE48 Stainless Mug, 16 oz
Good for: one person's coffee or tea, sipped on a train or at a desk.
Why we picked it: Zojirushi says 203°F (95°C) water still reads 154°F (68°C) after six hours. The flip lid locks, and the stopper comes apart for cleaning.
What to know: the 18/8 interior has a finish Zojirushi calls SlickSteel, and its plastic parts are BPA-free. A 12 oz (360 ml) SM-KHE36 also exists.
The drawback: hand wash only: Zojirushi says its jars and mugs are not dishwasher safe. The five-year warranty covers the insulation only.
See the Zojirushi mug on AmazonWant a travel mug you can sip from in the car instead? Our guide to coffee bottles covers sip lids.
Best thermos for hot food
For hot food like soup, chili or stew, get a wide-mouth food jar, preheat it with boiling water, and fill it close to the top. The Thermos Stainless King 16 oz is the lunch size, rated by Thermos at 9 hours hot. For a bigger appetite, go to 24 oz.
A wide mouth lets soup pour out and a spoon reach the bottom.
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Hot food pick
Thermos Stainless King Food Jar, 16 oz
Good for: one bowl of soup, chili or oatmeal for lunch.
Why we picked it: a wide mouth, 18/8 steel walls, a pressure relief stopper and a steel folding spoon. Thermos rates it at 9 hours hot and 14 cold, and calls the lid leak-proof when closed.
What to know: the folding spoon is stainless steel, per Thermos.
The drawback: it stays hot 5 hours less than the 24 oz jar, per Thermos, and it is top rack only.
See the Thermos 16 oz jar on Amazon
Big-lunch pick
Thermos Stainless King Food Jar with Bowl, 24 oz
Good for: a big lunch, or food you would rather eat from a bowl.
Why we picked it: Thermos rates it at up to 14 hours hot and 24 cold, with 18/8 steel walls and a built-in insulated serving bowl.
What to know: it weighs 1.2 lb (0.54 kg) empty and is top rack only.
The drawback: Thermos does not say what the serving bowl or the stopper is made of.
See the Thermos 24 oz jar on Amazon
Stew and pasta pick
Stanley Classic Food Jar, 24 oz
Good for: stew, pasta or chili for one big eater.
Why we picked it: Stanley's spec list gives 15 hours hot and 18 cold. The body is 90% recycled 18/8 steel, and the lid doubles as a cup.
What to know: Amazon sells it as the Heritage Classic; Stanley's page calls the 24 oz jar the Classic Legendary. Stanley says dishwasher safe.
The drawback: the page summary says 15 hours hot or cold, so treat the cold figure as a range. At 1.4 lb (0.64 kg) it is heavier than the Thermos 24 oz, and the warranty skips the lid and seal.
See the Stanley food jar on Amazon
Soft-lid pick
Hydro Flask Insulated Food Jar, 20 oz
Good for: a lunch a bit bigger than 16 oz, and hands that struggle with tight lids.
Why we picked it: Hydro Flask says it is 18/8 steel, BPA-free, leakproof when closed and dishwasher safe, with a soft grip lid that opens easily.
What to know: not for the stove, microwave or freezer, per Hydro Flask.
The drawback: Hydro Flask says only "for hours", so you cannot compare it on hold time. The lid material is not named.
See the Hydro Flask jar on AmazonPacking cold leftovers too? Our stainless steel food container guide covers that side.
How long it keeps hot, and how to make it last
These are maker claims. Each maker measures its own way, and only Zojirushi publishes its method (a 68°F, 20°C room), so compare within a brand more than across brands.
| Product | Hot | Cold |
|---|---|---|
| Stanley Classic bottle 1.1 qt | 24 h (page summary: 28 h) | 24 h, 5 days with ice |
| Thermos Stainless King bottle 40 oz | Up to 24 h | Up to 24 h |
| Zojirushi SM-KHE48 16 oz | 154°F (68°C) at 6 h, from 203°F (95°C) | 48°F (9°C) at 6 h, from 40°F (4°C) |
| Thermos food jar 16 oz | 9 h | 14 h |
| Thermos food jar 24 oz | Up to 14 h | Up to 24 h |
| Stanley food jar 24 oz | 15 h | 18 h (page summary: 15 h) |
| Hydro Flask food jar 20 oz | "For hours" | "For hours" |
Those hours assume you do the prep. Thermos's routine for a food jar:
- Fill it three-quarters full with boiling water, lid on loosely, for a full 5 minutes.
- Heat the food to above 165°F (74°C), hotter than you would serve it.
- Pour the water out and fill within 30 seconds.
- Fill to about half an inch (1 cm) from the top and keep it shut until you eat.
Thermos says to preheat a food jar with boiling water for 5 minutes before filling it.
Thermos says skipping the preheat, or opening the jar on the way, can cut the hot time by 30 to 50 percent. Zojirushi says the same: hot water in, stopper on, five minutes. For coffee, swirl kettle water in the bottle just before filling.
What touches your food: lids, gaskets and plastic
The steel is the easy part. All four makers say their steel is 18/8, and Thermos says its stainless products have no interior coating. Our guide to stainless steel grades explains what 18/8 means. The questions are in the lid.
The lid comes apart into cup, stopper and gasket ring. The gasket is the part to wash and replace.
- The stopper. Only Stanley names its stopper plastic: BPA-free polypropylene on the outside. Zojirushi and Hydro Flask say BPA-free without naming the plastic, and Thermos names its lid plastics only for its FUNtainer kids' line.
- The gasket. The soft ring that makes the seal. Thermos says gaskets hold moisture and food residue, so take it out and soak it on its own. Stanley suggests white vinegar, lemon juice or warm water with baking soda.
- Bleach. Skip it. Thermos says chlorine bleach can corrode stainless steel and break down rubber gaskets.
- Spare parts. Thermos and Stanley both sell replacement parts. Stanley's lifetime warranty does not cover lids or seals, so a worn gasket is a part you buy.
Stanley says the #7 on its bases is there because the product mixes materials, and that a base cap that comes off and exposes the seal underneath is covered by its warranty. Our guides to insulated tumblers and insulated and plain bottles explain what that seal is.
If you want to know which plastic sits in the lid, the Stanley Classic bottle is the one pick here whose maker says so.
Can a thermos go in the dishwasher?
Most can, on the top rack, but not all of them. Thermos and Hydro Flask say theirs are dishwasher safe, and Thermos adds top rack only with no heated dry. Stanley says to check the bottom of the product. Zojirushi says its jars and mugs are not dishwasher safe.
| Maker | Dishwasher? | The maker's wording |
|---|---|---|
| Thermos (40 oz bottle, 16 and 24 oz jars) | Yes, top rack only | "Dishwasher safe, top rack only." Skip the high-heat drying cycle. The bottle guide still prefers hand washing. |
| Stanley (1.1 qt bottle, 24 oz jar) | Yes, but check the base | Product pages say dishwasher safe. The FAQ says to check the bottom of your product, then use the top rack, away from the hottest water. |
| Zojirushi (SM-KHE48) | No | "Our jars and mugs are NOT dishwasher safe." Hand wash, and do not soak jars. |
| Hydro Flask (20 oz jar) | Yes | Dishwasher safe, or wash by hand in warm, soapy water. Avoid bleach. |
The Stanley bottle's Amazon listing says both dishwasher safe and hand wash only, so go by Stanley's advice and look at the bottom of the one you receive.
Whatever the rule, take the lid apart, wash the gasket, and let every part dry before you close it. Thermos says sealing a wet bottle is the main cause of mold and musty smells. For other bottle brands, see what Yeti, Stanley, Owala and Hydro Flask say, and for the rest of the kitchen, our list of things to keep out of the dishwasher.
No microwave: Stanley, Thermos and Hydro Flask all rule it out (see the FAQ below).
Which size to buy
Buy for the portion you will actually pack, so the jar or bottle goes out full.
| Size | Roughly holds | Good for | Picks here |
|---|---|---|---|
| 12 to 16 oz (355 to 473 ml) | One big mug or bowl | A commute or a work lunch | Zojirushi SM-KHE48, Thermos 16 oz jar |
| 20 to 24 oz (591 to 710 ml) | A big bowl | A hungry adult | Hydro Flask 20 oz, Thermos 24 oz, Stanley 24 oz |
| 1.1 qt to 40 oz (1 to 1.2 L) | Four to five 8 oz mugs | Coffee for two or three | Stanley 1.1 qt, Thermos 40 oz |
| 1.5 to 2 qt (1.4 to 1.9 L) | A pot of chili | A group or a job site | Not covered here |
For one adult's hot lunch, start with the Thermos 16 oz jar. Small kids' jars are covered in our lunch box guide.
Questions people ask
Stanley or Zojirushi?
They do different jobs. The Stanley is a 1.1 qt bottle you pour and share, and Stanley says it is dishwasher safe. The Zojirushi is a 16 oz mug one person sips from, and it is hand wash only. Their hold claims are measured differently.
Is a thermos better than an insulated tumbler?
For hours of heat, yes. A vacuum bottle closes with a sealed stopper, while most tumblers have a sip or slide lid for a desk or cup holder. Our tumbler guide shows which tumbler lids leak.
What grade of stainless steel does Thermos use?
18/8, per Thermos: about 18 percent chromium and 8 percent nickel. Stanley, Zojirushi and Hydro Flask say 18/8 too.
How long does a thermos keep food hot?
Thermos rates its Stainless King food jars at 9 hours hot for the 16 oz and 14 hours for the 24 oz, and Stanley rates its 24 oz Classic food jar at 15 hours. Each maker measures its own way, so read these as maker ratings, not side-by-side numbers.
Are thermoses dishwasher safe?
Most are, on the top rack. Thermos says top rack only, Hydro Flask says dishwasher safe, and Stanley says to check the bottom of your product first. Zojirushi says its jars and mugs are not dishwasher safe.
Can you put hot soup in a thermos?
Yes, in a preheated wide-mouth jar, heated to above 165°F (74°C) first, per Thermos. Its bottle care guide adds that dairy and tomato can spoil sooner, and that nothing should stay inside longer than 24 hours.
Can I use a thermos for tea or hot water?
Yes, in a narrow-mouth bottle. Take loose leaves out first, or the tea keeps steeping and turns bitter; a tea infuser makes that easy. Thermos says to check the temperature before you drink. For brewing at home, see our teapot guide.
Do thermoses leak?
A closed one should not: Thermos, Stanley and Hydro Flask all call theirs leakproof. Thermos says a missing, worn or misaligned gasket can cause leaks.
When should I replace the gasket?
No maker gives a schedule. Replace it when it cracks, stretches, stops sitting flat or keeps a smell after soaking; Thermos says the gasket is the likely source of odors that will not wash out.
Can you put a thermos in the microwave?
No. Stanley and Hydro Flask say not to, and Thermos says stainless steel can arc and damage the microwave. Heat the food in a pot or a microwave-safe bowl, then fill the jar.
The verdict
For coffee, get the Stanley Classic 1.1 qt and check the mark on its base before you load the dishwasher. For hot food, get the Thermos Stainless King 16 oz jar, or the 24 oz for longer hours, preheat it, and wash it on the top rack.
See the Stanley bottle on AmazonSee the Thermos food jar on Amazon
How we put this together
On 3 and 4 Nov 2026 we checked each pick's Amazon US listing for stock and size, then read the maker's product page, FAQ and care guide. Every hold time is the maker's figure, not ours, and no brand saw this page before it went up. Left out: kids' jars (see the lunch box guide), glass-lined flasks (no maker page found to check) and discontinued Zojirushi models.
Sources (maker pages, opened 3 and 4 Nov 2026).
- Thermos: Stainless King Beverage Bottle 40 oz
- Thermos: Stainless King Food Jar 16 oz
- Thermos: Stainless King Food Jar 24 oz
- Thermos: how to clean a stainless steel bottle
- Thermos: how to keep food hot in a food jar
- Thermos: FAQ
- Thermos: Stainless King bottle care and use guide (PDF)
- Stanley: Classic Heritage Bottle 1.1 qt
- Stanley: Classic Legendary Food Jar 24 oz
- Stanley: FAQ
- Zojirushi: Stainless Mug SM-KHE36/48
- Zojirushi: food jar FAQ
- Zojirushi: newsletter, August 2022
- Hydro Flask: 20 oz Insulated Food Jar
