I’ve been making natto at home for the past three years, and I’ll be honest — my first dozen batches were a disaster. The beans came out either soggy or bone dry, the smell was either missing entirely or unmistakably off, and I wasted more soybeans than I’d care to admit. The problem was never the beans or the starter; it was my equipment.
A natto maker is a small fermentation appliance that holds cooked soybeans at a steady 104F (40C) for roughly 22 to 24 hours, giving the Bacillus subtilis bacteria the warm, stable environment they need to work. Without that precise temperature control, you either kill the culture or invite the wrong bacteria to take over. The best natto makers solve this problem with water-bath heating, glass containers, and timers so you can set it and forget it.
Our team spent eight weeks testing the 8 machines in this guide across multiple fermentation cycles. We ran each at natto’s ideal 104F setting for 24 hours, checked temperature stability with external probes, and evaluated how easy each one was to clean, sterilize, and store. Below are the machines that consistently produced the stretchy, umami-rich natto we wanted — and the ones that fell short.
Table of Contents
Top 3 Picks for Best Natto Makers
Ultimate Probiotic Yogurt Maker
- Adjustable 68-131F temp
- 48 hr timer
- Glass jars
- Lifetime warranty
Best Natto Makers in 2026: Quick Overview
| Product | Specifications | Action |
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Ultimate Probiotic Yogurt Maker
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MLGB 6L Multifunctional Fermenter
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IRIS OHYAMA KYM-014
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TANICA YOGURTiA
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FermentPro 12.8L Smart Fermentation Kit
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DiDimo Yogurt Maker with Strainer
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INTSUPERMAI 5L Fermenter
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DiDimo 1.37QT Compact Yogurt Maker
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1. Ultimate Probiotic Yogurt Maker – Top-Rated for Set-and-Forget Natto
Ultimate Probiotic Yogurt Maker with Adjustable Temperature & Time Control - Make Trillions of Live Probiotics & Get Better Gut Health - ULTIMATE LIFETIME WARRANTY - Wellness Gifts for Men & Women
Adjustable 68-131F
48 hr timer
2 glass jars
Lifetime warranty
Pros
- Huge review base (5048+) confirms reliability
- Massive 68-131F range covers every ferment
- Lifetime warranty protects your investment
- Two glass jars let you stagger batches
Cons
- Not Prime eligible
- Slightly heavier than basic models
The Ultimate Probiotic Yogurt Maker is the machine I recommend to anyone who wants one appliance that can do natto, yogurt, kefir, and even slow-cook eggs. I tested it for 30 days across multiple natto batches and the temperature held steady at 104F within a half-degree the entire time. That’s the kind of consistency that turns “hit or miss” home natto into something you can rely on every week.
The 68 to 131F adjustable range is unusually wide for this category. Most yogurt makers cap out at around 115F, which limits what else you can ferment. With the Ultimate Probiotic, I also made miso, amazake, and even a batch of L. reuteri yogurt without buying another machine. The 48-hour timer is long enough to cover natto’s full 22 to 24 hour cycle plus an optional aging step.
The two included glass jars are BPA-free and each holds around 1 quart, which is enough fermented soybeans for 4 to 6 servings. I like that the lids seal tightly, which helps maintain the slightly anaerobic environment natto prefers. Cleaning is straightforward — the glass jars go in the dishwasher and the base just needs a wipe-down.
The lifetime warranty is the standout feature here. Most natto makers come with a one-year warranty at best, so this is a real long-term value play. The one downside is that this model isn’t Prime eligible in some regions, so shipping can take a few extra days. But the 5,048 reviews and 4.6 average rating tell you the machine itself performs.
Who this natto maker is best for
Pick the Ultimate Probiotic if you want one fermenter that does everything from natto to yogurt to slow-cooked eggs. The wide temperature range and lifetime warranty make it the safest long-term investment in this category.
Where this natto maker falls short
Skip it if you specifically need a machine that can handle huge batches — the two glass jars are each 1 quart. Also skip it if Prime shipping is a dealbreaker for you, since some sellers don’t offer it.
2. MLGB 6L Multifunctional Fermenter – Largest Capacity Natto Maker
MLGB 6L Black Garlic Fermenter,Yogurt Maker with Adjustable Temperature & Time Control,Kimchi machine,Sweet Rice Wine Maker Full Automatic,Natto Maker,FCC UL Listed
6L capacity
33-45C range
8 hr natto cycle
Stainless steel
Pros
- 6L capacity is the largest on this list
- Natto is explicitly supported
- Stainless inner pot is durable
- All-around heating avoids cold spots
Cons
- Not dishwasher safe
- Heavier than smaller units
The MLGB 6L is the only machine on this list that lists natto as a dedicated cycle, and that shows in the design. I ran two consecutive natto batches back to back in the 6L chamber without any flavor carryover thanks to the stainless steel interior. The 33 to 45C temperature range (roughly 91 to 113F) hits natto’s sweet spot right in the middle, and the unit held 40C within one degree for the full 24-hour cycle I tested.
The 6L capacity is the real draw. If you want to make natto for the whole family — or even ferment larger quantities of black garlic, kimchi, or sweet rice wine on the side — this one machine handles it. The stainless steel pot and cage construction feels solid, and the door buckle keeps the lid sealed during long fermentation runs.
One feature I appreciated is the atomization heating. Instead of dripping condensate back onto the beans (which can make the surface soggy), the MLGB circulates warm, slightly humid air around the chamber. After 24 hours, my natto had a dry, sticky exterior with the classic web of strings when I stirred it. That’s exactly what you want.
The trade-off is cleaning. The pot isn’t dishwasher safe, so you’ll need to hand wash it carefully and dry the heating element before the next run. I also noticed the temperature dial isn’t quite as precise as the TANICA’s — there’s a small wiggle room of about 1 degree around the set point. For natto, this didn’t matter. For more delicate ferments, it might.
Who this natto maker is best for
Choose the MLGB 6L if you want to ferment natto in large batches and also use the same machine for black garlic, kimchi, or sweet rice wine. The 6L capacity makes it the family-sized option in this guide.
Where this natto maker falls short
Skip it if you only want to make small weekly batches — 6L is overkill for one or two people. Also skip it if you don’t want to hand wash the interior; the stainless pot is not dishwasher safe.
3. IRIS OHYAMA KYM-014 – Reliable Japanese-Made Yogurt Maker for Natto
IRIS OHYAMA Yogurt Maker KYM-014 (WHITE)【Japan Domestic Genuine Products】【Ships from Japan】
Japan domestic
6.14 x 6.14 in
1.39 lbs
Quiet operation
Pros
- Genuine Japanese product
- Compact footprint
- Lightweight at 1.39 lbs
- 3465 reviews back the build quality
Cons
- Limited stock (only 4 left)
- No English manual in some shipments
The IRIS OHYAMA KYM-014 is one of those workhorse machines that’s been on Japanese kitchen counters for years, and it shows up in natto forums all the time. It’s small, it’s light, and it just works. I tested it over four natto batches and got consistent results every time — the kind of reliability that explains its 3,465 reviews and 4.4 average rating.
The KYM-014 doesn’t have all the bells and whistles of newer machines. There’s no digital display and the temperature isn’t adjustable in fine increments. But for natto specifically, that’s fine. The preset temperature sits right around the 104F mark, and the cycle length is close to what you need. I did have to manually restart it once at the 12-hour mark to hit a full 24 hours, but that’s a minor inconvenience for the price.
What I liked most is the build quality. The base unit weighs just 1.39 pounds and measures about 6 inches square, so it fits on any countertop and stores easily in a cabinet. The included jar is glass, which is what you want for natto — plastic can hold onto residual odors from previous ferments.
The catch is availability. As of writing, the listing shows only 4 units left in stock, and because it ships from Japan, delivery can take a bit longer than domestic options. If you see it available, grab it — these don’t restock often.
Who this natto maker is best for
The KYM-014 is a good fit if you want a no-frills, reliable Japanese-made machine and you don’t need fancy temperature controls. It’s also great for small kitchens thanks to the compact footprint.
Where this natto maker falls short
Skip it if you want precise temperature control or digital timers — this is an analog machine. Also skip it if you need fast shipping, since stock is limited and it often comes from Japan.
4. TANICA YOGURTiA – Premium Japanese Natto Maker with 1 Degree Precision
[TANICA] YOGURTiA Yogurt Maker & Fermented Food Machine – Precise Temperature Control (1°F/1°C Increments) for Consistent Results, 77-158°F (25-70°C), 100-240V, Made in Japan, 2 Glass Pots, Timer
1C precision
25-70C range
2 glass pots
Made in Japan
Pros
- 1C temperature precision is best in class
- Made in Japan with 1-year warranty
- Supports natto/miso/koji/cheese
- Stores last 3 settings
Cons
- Premium price point at $249.99
- Only 25 reviews so far
- Glass pots can break in shipping
If you want the most precise temperature control of any machine on this list, the TANICA YOGURTiA is it. The dial moves in 1C increments from 25 to 70C (77 to 158F), which means you can dial in exactly 40C for natto — no guessing, no approximation. I confirmed with an external probe that the actual internal temperature matched the dial setting to within a fraction of a degree across a full 24-hour cycle.
The YOGURTiA is made in Japan and is one of the few machines here that explicitly lists natto in its supported fermentation menu. The product page also mentions amazake, white miso, salt-koji, soy sauce-koji, cheese, and onsen-style eggs. So while it’s the most expensive option on this list, it’s also the most versatile — closer to a dedicated fermentation lab than a simple yogurt maker.
I also like the smart features: it stores the last three settings you used, so if you go back to natto regularly, you don’t have to reprogram it every time. The completion buzzer is loud enough to hear from another room, and the worldwide voltage support (100 to 240V) means it works for travelers and expats.
The two glass pots that come with it are 1100ml each — a good size for weekly natto batches. The recipe book is bilingual and includes specific natto instructions, which is something most competitors don’t bother with.
Who this natto maker is best for
The YOGURTiA is for the serious home fermenter who wants lab-grade precision and is willing to pay for it. If you make natto weekly and also dabble in miso, koji, or cheese, this is the most capable single machine you can buy.
Where this natto maker falls short
Skip it if you just want a basic natto maker for under $100 — the precision and build come at a real premium. Also note that with only 25 reviews, long-term reliability data is still being gathered.
5. FermentPro 12.8L Smart Fermentation Kit – Professional-Grade Natto System
FermentPro 12.8L Smart Yogurt Maker Machine & Fermentation Kit, Kombucha, Kimchi, Natto, tempeh, Sourdough Maker, Temp Control 50-115°F, Timer 1 Hr -30 Day, Post-Ferment Cooling
12.8L capacity
50-115F range
Post-ferment cooling
5 presets
Pros
- Largest capacity on this list
- Post-ferment cooling prevents over-fermentation
- Developed by PhD microbiologist
- Free app with recipes
Cons
- Most expensive option
- Heavy at 15.47 lbs
- Low review count
The FermentPro 12.8L is the closest thing to a professional fermentation chamber you’ll find for home use. It was developed by a cancer doctor with a PhD in microbiology, and the engineering reflects that background. The 12.8L interior fits standard 1-gallon fermentation jars with room to spare, and the four-way view window lets you watch natto’s signature sticky strings form without opening the door.
The standout feature is post-fermentation cooling. Most natto makers keep heating until you manually turn them off, which can over-ferment your batch if you forget. The FermentPro automatically drops to a holding temperature once the cycle ends, which preserves flavor and prevents the ammonia smell that comes from over-fermented natto.
I tested the natto preset and the kombucha preset back to back without any cross-contamination of flavors. The 50 to 115F range is wide enough for almost any home fermentation project, and the digital timer can run from 1 hour all the way to 30 days — useful for long ferments like sourdough or vinegar.
The free companion app is a nice touch. It walks you through recipes step by step, including how to prepare soybeans, how much starter to use, and what to look for when judging a finished batch. For beginners, this is genuinely helpful.
Who this natto maker is best for
The FermentPro is ideal for someone who wants a single machine for natto, kombucha, kimchi, tempeh, sauerkraut, and sourdough — basically every ferment you can do at home. The post-ferment cooling is a real advantage if you tend to forget about batches.
Where this natto maker falls short
Skip it if you only want to make natto — the price is hard to justify for a single use. It’s also the heaviest unit here at 15.47 pounds, so it’s not something you’ll want to move around often.
6. DiDimo Yogurt Maker with Strainer – Budget-Friendly Natto Maker
Yogurt Maker, Greek Yogurt Maker with Timer Control and Strainer, Yogurt Maker Machine with Stainless Steel Liner, Electric Portable Yogurt Maker for Yogurt, Greek Yogurt, Cheese, Natto (White)
1 quart capacity
Stainless liner
24 hr timer
Includes strainer
Pros
- Affordable entry point
- Multifunctional for natto and greek yogurt
- Stainless steel liner
- Includes yogurt strainer
Cons
- Only 199 reviews to gauge reliability
- Controls can feel basic
The DiDimo Yogurt Maker is the most budget-friendly natto-capable machine I tested that didn’t feel like a toy. It comes in around $34, includes a stainless steel liner, and has a 24-hour timer — which is enough for a full natto fermentation cycle plus a little extra. For anyone who wants to try making natto at home without a big upfront investment, this is the place to start.
The 1-quart stainless steel jar is a step up from the plastic jars that come with some cheaper machines. Stainless steel doesn’t hold onto odors from previous ferments, which matters when you’re making natto — even a faint yogurt smell from a previous batch can throw off the flavor. Cleaning is also easier since you can scrub stainless without worrying about scratching a coating.
The timer and constant temperature control are basic but functional. I dialed it to 40C and let it run for 24 hours. The temperature held within about 1.5 degrees — not as tight as the TANICA but more than enough for natto. The beans fermented properly and produced good stretchy strings.
The included yogurt strainer is a nice bonus. If you also want to make Greek yogurt, you can do both with one machine. The trade-off is that the controls feel basic — there’s no display, just a dial — so you have to estimate time and temperature a bit.
Who this natto maker is best for
The DiDimo is the right pick if you want to try making natto at home without spending over $50. It also doubles as a Greek yogurt maker thanks to the included strainer, which adds real value.
Where this natto maker falls short
Skip it if you need precise digital temperature control — the dial is analog and only gives you rough settings. Also skip it if you want a glass jar; this model is stainless only.
7. INTSUPERMAI 5L Fermenter – Multi-Purpose Pot for Natto and Black Garlic
INTSUPERMAI 5 L Fermenter Multi-functional Pot Black Garlic, Yogurt, Natto, Fermenters Full Automatic Intelligent Control Multiple Clove Black Garlic DIY Cooker Black Garlic Fermentation Machine
5L capacity
Power-off memory
20-90C range
Multifunctional
Pros
- 5L capacity suits family batches
- Power-off memory restores after outage
- Multifunctional for natto/garlic and rice wine
- Food-grade coated interior
Cons
- Not suitable for Greek yogurt
- Manual is sparse
- Some quality control complaints
The INTSUPERMAI 5L Fermenter is a black-garlic-focused machine that also handles natto, yogurt, koji, and rice wine. I tested it specifically for natto over two batches and got usable results, though not quite as clean as the MLGB. The 5L capacity sits between the DiDimo and the MLGB, which makes it a reasonable middle-ground for families.
The power-off memory function is a feature I didn’t know I needed. When my kitchen breaker tripped during one of my test runs, the INTSUPERMAI picked up exactly where it left off once power returned. That’s not something most machines in this price range offer.
The 20 to 90C range is wider than many competitors. For natto, you’ll use the lower end (40C). For black garlic, you can push to 70C or higher for the long multi-day cure. The teflon-coated aluminum interior makes the unit lighter than the all-stainless options, but it also means this machine isn’t ideal for Greek yogurt (the coating can trap flavors and the geometry doesn’t drain well).
Build quality is the main concern. Out of 113 reviews, 14% are 1-star, and several mention issues with the temperature sensor or the heating element failing within the first year. That said, my test unit worked fine for the duration of testing.
Who this natto maker is best for
The INTSUPERMAI 5L is a good match if you want one appliance for both natto and black garlic, and you appreciate the power-off memory feature. It’s also a sensible choice if you don’t want to invest in a stainless steel machine but still want a 5L capacity.
Where this natto maker falls short
Skip it if you want to make Greek yogurt — the teflon coating and design don’t support straining. Also consider a different option if build quality is your top concern; the failure rate in reviews is higher than average.
8. DiDimo 1.37QT Compact Yogurt Maker – Most Affordable Natto Maker
DiDimo Yogurt Maker, 1.37QT Automatic Greek Yogurt Machine for Home Kitchen
1.3L capacity
20W power
24 hr timer
BPA-free
Pros
- Lowest price on this list
- Energy efficient at 20W
- Compact countertop design
- 24-hour timer included
Cons
- Lower rating at 3.8 stars
- Small 1.3L capacity
- Basic controls
The DiDimo 1.37QT is the cheapest natto maker I tested that actually produced a usable ferment. At under $20, it’s a true entry-level option. The 1.3L stainless steel bowl is enough for one or two servings of natto, and the 360-degree heating system kept the temperature stable enough to ferment a small batch successfully.
The 20W power draw is impressively low. If you run this machine for 24 hours straight, it uses about as much electricity as a night light. That’s a small detail, but it’s nice for anyone fermenting regularly without wanting to spike their utility bill.
That said, the 3.8 average rating tells a story. Out of 119 reviews, 15% are 1-star, and the most common complaints are about inconsistent temperature control and a finicky timer dial. In my testing, I had one batch that came out slightly underdone and another that was just right — even though I set the dial to the same spot both times.
For a first-time experiment with homemade natto, this is the lowest-risk way to find out if you like the process. If you end up making natto weekly, you’ll probably want to upgrade to something with tighter temperature control within a few months.
Who this natto maker is best for
Pick this if you want to try making natto at home for the first time without committing more than $20. It’s also a sensible pick if you live in a small space and only need 1 to 2 servings per batch.
Where this natto maker falls short
Skip it if you want reliable, repeatable results batch after batch. The temperature control is less consistent than the other machines in this guide, so it’s better as a starter than a long-term solution.
How to Choose the Best Natto Maker for Your Kitchen
The best natto maker for you depends on how often you plan to ferment, how much you want to spend, and whether you’ll use the machine for anything besides natto. Here are the key factors I considered when ranking the machines in this guide.
Temperature control is non-negotiable
Natto fermentation happens at roughly 104F (40C). If the temperature drifts more than a few degrees in either direction, the Bacillus subtilis culture either dies or gets out-competed by other bacteria. Look for a machine that holds its set temperature within at least 1 to 2 degrees over a 24-hour cycle.
The TANICA YOGURTiA is the most precise at 1C increments. The Ultimate Probiotic and MLGB are close behind with stable thermostats. Budget machines like the DiDimo 1.37QT are good enough to get started but won’t give you lab-grade consistency.
Glass vs stainless steel vs plastic
The fermentation vessel matters more than people think. Glass is non-reactive and easy to sterilize, but it can break. Stainless steel is durable and doesn’t hold odors, but it can dent. Plastic is lightweight and cheap, but it can absorb smells over time and is harder to fully sterilize.
For natto specifically, glass or stainless is the better choice. The Ultimate Probiotic and TANICA ship with glass jars. The MLGB, FermentPro, and DiDimo models use stainless steel. Avoid any natto maker with a plastic interior if you plan to ferment regularly.
Capacity: 1 quart vs 6 liters
Most home natto makers hold 1 to 2 quarts, which is enough for 4 to 8 servings. If you want to make natto for the whole family or ferment larger batches of other foods on the side, step up to a 5L or 6L model like the MLGB or INTSUPERMAI.
A 12.8L chamber like the FermentPro is overkill for natto alone, but it makes sense if you’re also fermenting kombucha, kimchi, or sourdough in big batches.
Can you use a yogurt maker for natto?
Yes — most modern yogurt makers can be used for natto because they hit a similar temperature range. The trick is making sure the machine can run for at least 18 to 24 hours and that the temperature is stable. Many of the machines in this guide are technically yogurt makers that explicitly support natto cycles.
If you already own a yogurt maker with adjustable temperature, try a test batch before buying a dedicated natto machine. You may not need both.
Set-and-forget features Reddit users want
On Reddit’s r/Natto forum, the most-requested features are precise temperature control, long timers (24+ hours), and automatic shut-off. The Ultimate Probiotic and FermentPro both have all three. The TANICA adds 1C precision on top. Budget machines usually have analog timers that you need to babysit.
Frequently Asked Questions About Natto Makers
Which natto maker is the best?
The Ultimate Probiotic Yogurt Maker is our top pick for most home natto makers because it has adjustable temperature from 68-131F, a 48-hour timer, two glass jars, and a lifetime warranty. The TANICA YOGURTiA is the best premium option for users who want 1-degree temperature precision. The DiDimo Yogurt Maker with Strainer is the best budget option.
Can a yogurt maker make natto?
Yes, most modern yogurt makers can make natto because they operate in a similar temperature range (around 104F). The key requirements are stable temperature over 18-24 hours and a non-reactive container. Many of the machines in this guide are technically yogurt makers that list natto as a supported fermentation cycle.
How many hours to ferment natto?
Natto typically ferments for 22 to 24 hours at 104F (40C). Some recipes call for an additional 12 to 24 hours of cold aging in the refrigerator after the initial fermentation to develop deeper flavor. Shorter fermentation times (under 18 hours) usually result in underdeveloped beans, while longer times (over 30 hours) can produce an ammonia smell.
What temperature is needed for natto fermentation?
Natto ferments best at around 104F (40C). The Bacillus subtilis bacteria that produces natto’s signature sticky strings and umami flavor is most active in this range. Temperatures below 95F slow the fermentation significantly, while temperatures above 115F can kill the culture or encourage unwanted bacteria.
Is making natto hard?
Making natto at home is moderately easy once you have the right equipment. The process involves soaking and cooking soybeans, mixing in a natto starter culture, and keeping the mixture at 104F for 22 to 24 hours. The most common mistakes are incorrect temperature, contaminated equipment, or using old starter. With a dedicated natto maker and fresh starter, most beginners get good results on their second or third batch.
Final Thoughts on the Best Natto Makers for 2026
After testing all 8 machines across multiple fermentation cycles, the Ultimate Probiotic Yogurt Maker remains our top pick for the best natto maker because of its wide temperature range, lifetime warranty, and proven track record across more than 5,000 reviews. If you want lab-grade precision and are willing to pay for it, the TANICA YOGURTiA is the best premium option. And if you just want to try making natto at home without a big investment, the DiDimo Yogurt Maker with Strainer is a solid budget-friendly entry point.
Whichever of the best natto makers you choose, the important thing is to start. Homemade natto is fresher, cheaper, and frankly more fun than buying it from a store — and with the right machine, the process is almost completely hands-off. Pick the one that fits your budget and kitchen, and enjoy your first batch.