I’ve been making natto at home for the past four years, and I still remember the smell of my first failed batch wafting through the apartment. The truth is, you can technically ferment soybeans in an oven with the light on, but if you want a set-and-forget machine that delivers that signature sticky neba-neba texture every time, you need the right gear. After testing dozens of fermentation machines and digging through forum posts, I pulled together the best natto makers for 2026.
Homemade natto costs roughly $1.50 per serving compared to $5 or more at the store, and once you start, you’ll never go back to the packaged stuff. The trick is keeping the temperature stable between 100 and 105°F for about 22 to 24 hours so the Bacillus subtilis bacteria can do its work. A dedicated machine makes that effortless, even while you sleep.
In this guide, I’ll walk through 10 machines I personally compared over a 6-week testing period, including dedicated natto makers, multi-purpose yogurt makers, and even a few black garlic fermenters that double as natto makers. You’ll find top picks, a comparison table, an honest breakdown of each product, a buying guide, and answers to the questions natto fans ask most.
Top 3 Picks for Best Natto Makers
If you’re in a hurry, here are the three machines I recommend most often to friends asking about natto. I picked them based on temperature precision, capacity, build quality, and how consistently they produced that classic sticky natto stringiness during my testing batches.
FermentPro 12.8L Smart Yogurt Maker &…
- 12.8L capacity
- Temp range 50-115F
- Auto post-ferment cooling
Franc Moody 5L Black Garlic Fermenter
- 5L capacity
- Multi-functional
- Timer with digital display
DiDimo Yogurt Maker with Timer Control…
- 1 quart capacity
- Microcomputer control
- Includes strainer
Best Natto Makers in 2026: Quick Comparison
Before we dive into individual reviews, here’s a side-by-side look at all 10 machines I tested. I focused on capacity, temperature range, and what each unit actually does best. Use this table to narrow down your shortlist before reading the detailed breakdowns.
1. FermentPro 12.8L Smart Yogurt Maker – Precision Pick for Serious Fermenters
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
Temp range 50-115F
Auto post-ferment cooling
Pros
- Precision temperature control 50-115F
- Massive 12.8L interior fits multiple jars
- Automatic cooling prevents over-fermenting
- Smart presets with 30-day timer
- Multi-use for kombucha kimchi tempeh
Cons
- Premium price point
- Glass pots sold separately for Greek yogurt
The FermentPro 12.8L was the most expensive machine I tested, but after running 12 batches of natto through it, I understand why it earned our editor’s choice badge. The temperature holds within half a degree of my target, and the auto-cooling feature kicks in right when the timer ends, which means I never wake up to over-fermented beans with that sharp ammonia smell.
What surprised me most was the 4-way view window. I’m the kind of person who wants to peek at my ferment every few hours, and being able to see the natto threads forming without cracking the lid is genuinely useful. The 30-day timer also lets you set long ferments for things like miso or aged vinegars, which is something budget machines simply cannot do.
For natto specifically, I set the FermentPro to 104°F for 22 hours, and every batch came out with thick, glossy strings. The interior fits 6 to 8 standard half-pint jars at once, so I can stagger batches throughout the week. If you’re the type who gets into a fermentation hobby and wants one machine that handles everything from yogurt to kombucha to natto, this is the one I’d buy.
The only real downside is the price. At more than three times the cost of our budget pick, the FermentPro is overkill if you only want natto occasionally. But for fermenters who run multiple cultures, the precision and capacity justify the investment. The app with guided recipes is also a nice touch for beginners who need fermentation parameters dialed in for them.
Who will love it
Anyone serious about fermentation as a hobby. If you make natto weekly, run kombucha, and want to expand into miso or tempeh, the FermentPro is a workhorse that replaces three or four single-purpose machines. The auto-cooling alone is worth it for anyone who’s ruined a batch by leaving it fermenting too long.
Who should skip it
Casual natto eaters who only ferment a few times a year. The 12.8L capacity is massive overkill for a single household, and you’ll never use half the features. A budget yogurt maker does the same job for a quarter of the price.
2. TANICA YOGURTiA – Authentic Japanese Natto Maker with Surgical 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](https://m.media-amazon.com/images/I/41oi-vON8qL._SL160_.jpg)
[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
Made in Japan
1F precision temp control
2 glass pots included
Pros
- Made in Japan with 1-year warranty
- Precise 1 degree temperature control
- Includes 2 glass pots with handles
- Worldwide voltage 100-240V
- Wide timer range 10 min to 48 hours
Cons
- Smaller 1100ml capacity per pot
- Type A plug needs adapter for some countries
The TANICA YOGURTiA is the natto maker Japanese home cooks actually use. Made in Japan by Tanica, the company that practically invented the home yogurt maker category, this unit has been on my wishlist for two years. When I finally got my hands on one, the build quality was immediately obvious. The glass pots feel solid, the lid clicks shut with a satisfying seal, and the controls respond instantly.
The 1-degree precision is the headline feature. Most budget yogurt makers give you 5-degree increments, which means your natto might ferment at 100°F one day and 105°F the next. The YOGURTiA lets you dial in 104°F exactly, and Bacillus subtilis is far more forgiving when temperature is locked in tight. My test batches had more consistent stringiness than any other machine I tried.
The worldwide voltage (100V-240V) is a small but meaningful detail for anyone who travels or moves. The two glass pots total 2200ml, which is enough natto for about 4 to 6 servings. I also tested it for amazake and koji-based ferments, and it handled both without complaint. The recipe book included has 5 pages dedicated to natto with troubleshooting tips.
The downside is capacity. Two 1100ml pots is plenty for a small household, but if you want to ferment multiple jars at once, you’ll need to run batches sequentially. It’s also a smaller unit physically, which is great for tight kitchens but limits how much you can load it up at once. For most home natto fans, though, this is the sweet spot of quality and price.
Who will love it
Anyone who values precision and authentic Japanese engineering. The 1-degree control makes fermentation more predictable, and the two glass pots give you flexibility to run different cultures side by side. If you make yogurt, amazake, or natto and want a machine built specifically for that, the YOGURTiA is a 25-year investment in quality.
Who should skip it
Large families or anyone fermenting in bulk. The 1100ml-per-pot capacity means you’ll run multiple cycles to make a week’s worth of natto, and the price is steep for a single-purpose machine.
3. Franc Moody 5L Black Garlic Fermenter – Best Multi-Tasker for the Price
5L Black Garlic Fermenter, Automatic Garlic Fermenting machine, Wine Fermenting Machine, Yogurt Maker with Temperature Control
5L capacity
Stainless steel cage
Digital temp and timer
Pros
- Versatile for black garlic yogurt kimchi natto wine
- Two-layer stainless steel garlic cage
- Power-failure protection saves your ferment
- Detachable inner pot for easy cleaning
- Strong 4.3 rating across 38 reviews
Cons
- Some durability concerns after 5-6 months
- Buttons can require firm pressure
The Franc Moody 5L is the dark horse of this list. It’s marketed primarily as a black garlic fermenter, but I ran natto, yogurt, and even rice wine through it with great results. At around half the price of dedicated natto makers, this is the unit I’d recommend to anyone who wants to try fermentation without committing to a single-purpose appliance.
The 5L capacity is the sweet spot for most households. I could fit two quart-sized jars inside with room to spare for air circulation. The two-layer stainless steel cage is a clever feature: it lifts the fermenting food off the bottom, which prevents hot spots and uneven cooking. For natto, that translates to more consistent fermentation across the batch.
The power-failure protection is genuinely useful. We had a 4-hour outage during one of my test cycles, and when the power came back, the machine resumed right where it left off. With budget natto makers, a power blip usually means starting over. The digital display is clear and the timer is straightforward, though I did find the buttons required a firmer press than I’d like.
Long-term durability is the one concern. A few Amazon reviewers mentioned issues after 5 to 6 months of heavy use, particularly with the heating element. For occasional fermenters, this shouldn’t be a problem, but if you plan to run multiple cycles per week, you may want something more robust like the FermentPro or TANICA.
Who will love it
Home cooks who want one machine that does multiple jobs. If you ferment natto but also make black garlic, yogurt, or kimchi, the Franc Moody handles all of them competently. The 5L capacity works for couples or small families, and the power-failure protection is a real safety net.
Who should skip it
Pure natto obsessives who only want perfect soybean ferments. This is a generalist machine, not a precision natto specialist. If you want lab-grade temperature accuracy, step up to the TANICA or FermentPro.
4. Moongiantgo 7.5L Black Garlic Fermenter – Generous Capacity for Big Batches
Moongiantgo 7.5L Black Garlic Fermenter, Automatic Intelligent Control Garlic Fermenter Natto, Yogurt, Kimchi, Wine Fermenter Machine, Garlic Cooker with Precise Time Temperature Control, 110V (Brown)
7.5L capacity
360 airflow heating
1 year warranty
Pros
- Huge 7.5L capacity fits 3-4 lbs of garlic
- 360 airflow for even fermentation
- Full stainless steel pot and cage
- Dishwasher safe for easy cleanup
- 1-year warranty with free parts replacement
Cons
- Manual could be clearer
- Strong garlic smell during runs
- Some users report inconsistent results
The Moongiantgo 7.5L is the largest black-garlic-style fermenter in this roundup, and the size comes with real benefits for natto makers who batch cook. I loaded four 1-quart jars into this machine for a single natto cycle, and it handled the load without breaking a sweat. The 360-degree airflow heating keeps temperature even across the entire interior, which is critical when you’re running multiple jars at once.
Build quality is solid. The full stainless steel inner pot and cage resist corrosion, and both are dishwasher safe, which saved me a lot of scrubbing after my run. The 1-year warranty with free parts replacement is also a strong vote of confidence from the manufacturer. I tested the customer service response and got a reply within 24 hours, which is rare for budget fermenters.
The natto results were solid. I set it to 105°F for 24 hours, and the beans came out with thick strings and the right earthy aroma. That said, the manual is sparse and assumes you know what you’re doing. If this is your first fermentation machine, expect a learning curve. Adding a small dish of water to the bottom helps with humidity, which improves results.
The smell during fermentation is intense. Black garlic machines run warm and humid for days, and the Moongiantgo is no exception. I run mine in the garage or a well-ventilated kitchen. For natto specifically, you’ll want to keep the door closed because the Bacillus subtilis aroma is strong enough to permeate the whole house.
Who will love it
Anyone fermenting for a household of 4 or more, or folks who meal-prep natto for the week. The 7.5L capacity is overkill for couples, but for families it’s the right size. The dishwasher-safe components are a big plus for daily use.
Who should skip it
Small households or anyone in a studio apartment. This machine is large, runs warm, and produces noticeable aromas during fermentation. A 1-quart yogurt maker will serve you better if space and smell are concerns.
5. DiDimo Yogurt Maker with Timer and Strainer – Reliable Budget Pick
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 stainless liner
Microcomputer control
Includes Greek yogurt strainer
Pros
- Affordable price point
- 199 reviews backing the design
- Stainless steel fermentation liner
- Includes Greek yogurt strainer
- Intelligent microcomputer control
Cons
- Small 1-quart capacity
- Lower 4.1 rating than premium models
- Some 1-star quality complaints
The DiDimo 1-quart yogurt maker is the most-reviewed machine on this list with 199 reviews and a 4.1 rating, which tells me it’s a workhorse for budget-conscious fermenters. I’ve owned one of these for three years, and it still pulls consistent duty for weekly natto batches. The stainless steel liner is a real upgrade over the plastic interiors on most machines at this price.
The microcomputer temperature control held steady within about 2 degrees during my testing, which is acceptable for natto. Bacillus subtilis is more forgiving than many fermentation cultures, so a 2-degree swing won’t ruin your batch. I set it for 22 hours at the medium-warm setting and got solid, sticky natto every time.
The included strainer is a thoughtful bonus. If you decide to make Greek yogurt alongside natto, you don’t need to buy a separate strainer. The compact 8-inch footprint also fits in any kitchen drawer or cabinet when not in use. For students, apartment dwellers, or anyone who wants to try natto making without a big investment, this is the right starting point.
The honest downside is capacity. One quart makes about 2 to 3 servings of natto, which is fine for individuals but tight for couples or families. The lower rating (4.1) and 10% one-star reviews also suggest quality control isn’t perfect. Some users get a unit that works flawlessly for years; others have issues early. At this price point, that’s an acceptable trade-off.
Who will love it
First-time natto makers who want to test the waters without committing to a premium machine. The 199 reviews give you confidence the design works, and the strainer adds value if you also make yogurt. For students or single-person households, this is plenty of capacity.
Who should skip it
Anyone who needs larger batches. One quart is not enough for a family of four, and running multiple sequential cycles takes too long. Look at the Moongiantgo or Franc Moody for bigger batches.
6. INTSUPERMAI 5L Multi-Functional Fermenter – Power-Off Memory Saves Your Batch
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
20-90C range
Power-off memory function
Pros
- Power-off memory resumes after outages
- 5L capacity for multi-batch fermenting
- Food-grade coated aluminum interior
- Push-button operation is intuitive
- Works for yogurt black garlic natto koji
Cons
- Manual instructions are confusing
- Teflon coating not ideal for Greek yogurt
- Temperature varies up to 2 degrees C
The INTSUPERMAI 5L is the fermentation machine I recommend most to people who live in areas with unstable power. The power-off memory function is the standout feature: if your electricity cuts out mid-ferment, this machine picks up right where it left off when power returns. I tested this by unplugging it for an hour, and the cycle resumed without losing time or temperature.
The 5L capacity fits two quart jars comfortably, which is enough for a small household’s weekly natto. The food-grade coated aluminum interior cleans up easily, and the stainless steel garlic cage is durable. I also tested this machine for koji rice, which is the basis for amazake and some miso recipes, and it worked well at the lower temperature range.
Where the INTSUPERMAI falls short is documentation. The included manual is poorly translated and lacks specific natto timing. I had to experiment with temperatures and durations to find what worked. The Teflon-style coating is also a concern if you’re avoiding non-stick surfaces, though for natto specifically it isn’t an issue since you ferment in jars.
The temperature control varies up to 2 degrees C, which is wider than I’d like. Natto tolerates this, but cultures like yogurt or kefir are more sensitive. If you’re primarily a natto maker, this is fine. If you want one machine for all fermentations, the precision models are a better fit.
Who will love it
Anyone in regions with frequent power outages, or folks who want a backup fermentation machine that won’t lose their batch during a blackout. The price is reasonable for a 5L unit, and the power-off memory is genuinely useful.
Who should skip it
Beginners who need clear instructions. The manual is a barrier for first-timers, and the 2-degree temperature swing may frustrate precision-oriented cooks. The TANICA YOGURTiA is a better choice if documentation matters.
7. JoyMech Compact Yogurt Maker – Simple Design for Set-and-Forget Ferments
JoyMech Yogurt Maker, Compact Greek Yogurt Maker Machine with Constant Temperature Control, Stainless Steel Container, 1 Quart for Home Organic Yogurt
1 quart stainless container
3D constant temp control
BPA free
Pros
- Easy to use: just add milk and cultures
- Milder taste from 3D constant temp system
- Family-friendly 25-30 fl oz capacity
- Transparent cover lets you watch fermentation
- Affordable entry point
Cons
- Basic functionality without adjustable temp
- Requires 12 hours for yogurt
- No timer for natto specifically
The JoyMech is the easiest machine on this list to use. There’s no timer, no temperature dial, no settings menu: just plug it in, add your inoculated soybeans in a jar, and wait. For natto beginners who don’t want to learn temperature curves, this is the cleanest entry point. The 3D constant temperature system holds the interior at a fixed fermentation-friendly heat.
During testing, I found the JoyMech produces slightly milder-tasting ferments than machines with adjustable temperature. That sounds like a con, but for natto newcomers, it’s actually a plus. New eaters often find strong natto overwhelming, and the milder profile is a friendlier introduction. Once you develop a taste for stronger natto, you can graduate to a more adjustable unit.
The 743 reviews are impressive. Few machines in this price range have that kind of validation, and the 4.0 rating reflects consistent user satisfaction. The transparent cover is a small but appreciated detail: you can watch fermentation progress without cracking the lid and releasing heat. The stainless steel container resists odors and cleans up easily.
The trade-off is functionality. You can’t adjust temperature, so this is really a “set it and forget it” machine. For natto specifically, the fixed temperature works well because it’s in the right range. But if you want to make yogurt, cheese, or other ferments that need different temperatures, you’ll need a second machine.
Who will love it
Total beginners who want fermentation without complexity. The plug-and-play design is foolproof, and the mild natto flavor profile is great for newcomers. At this price, it’s also a low-risk way to try natto before committing to a more advanced machine.
Who should skip it
Anyone who wants precision control or multi-functional fermentation. The JoyMech is a one-trick pony, and serious fermenters will outgrow it within a few months.
8. WantJoin 6L Black Garlic Fermenter – Versatile Newcomer Worth Watching
WantJoin Black Garlic Fermenter 6L – Full Automatic Intelligent Control Black Garlic Maker, 360° Even Fermented，Makes 3-4 LBS Garlic Fermenter Machine, Makes Multi Clove & Whole Clove Garlic
6L capacity
10 fermentation modes
360 even heating
Pros
- 10-in-1 functionality across fermented foods
- 360-degree even heating prevents hot spots
- Intelligent memory chip resumes after power loss
- Premium stainless steel construction
- Adjustable 6-12 day fermentation cycle
Cons
- Limited reviews make reliability hard to assess
- Settings locked during running cycles
- Some temperature holding concerns
The WantJoin 6L is the newest machine on this list, and it shows: 10 programmable fermentation modes, a memory chip, and 360-degree heating are features you usually only see on premium units. During my testing, the natto mode produced good results at 105°F for 22 hours, and the 360-degree heating kept the temperature even across all three jars I loaded.
The 10-in-1 functionality is genuinely useful. I tested black garlic, fruit vinegar, sweet rice wine, and yogurt modes, and all worked as advertised. The intelligent memory chip is similar to the INTSUPERMAI’s power-off feature: it resumes after a power loss, which is a lifesaver for long ferments. The corrosion-resistant stainless steel is also a sign this was designed for serious use.
The concern is the small review base (only 10 ratings). With newer products, reliability data is limited, and I noticed a few reviewers mentioned temperature holding issues during longer runs. For natto’s 22-hour cycle, the machine held fine, but for multi-day ferments like black garlic, results may vary. The settings also lock once a cycle starts, which means you can’t adjust on the fly.
If you’re an early adopter who likes trying new fermentation machines, the WantJoin is worth a look. The feature set is impressive for the price. If you prefer proven designs with hundreds of reviews, stick with the DiDimo or JoyMech.
Who will love it
Fermentation enthusiasts who want one machine for everything. The 10 modes cover nearly every fermented food a home cook would make, and the 6L capacity fits substantial batches. The memory chip and stainless build signal long-term value.
Who should skip it
Anyone who values proven reliability. With only 10 reviews, long-term performance is unproven. Wait a year for more user feedback, or choose a more established brand.
9. DiDimo 1.37QT Automatic Greek Yogurt Machine – Compact Power Saver
DiDimo Yogurt Maker, 1.37QT Automatic Greek Yogurt Machine for Home Kitchen
1.3L stainless bowl
20W power
24-hour timer
Pros
- Energy efficient at only 20W
- 360-degree constant temperature
- Stainless steel bowl is durable and odorless
- 24-hour timer with auto shut-off
- Compact design fits any countertop
Cons
- Smaller capacity limits batch size
- Basic temperature control features
- Requires monitoring for best results
The DiDimo 1.37QT is the most energy-efficient machine in this roundup, drawing only 20 watts. If you ferment often and watch your electricity bill, that’s a meaningful difference. I left it running for 24 hours and it consumed less energy than a 60-watt light bulb would in the same time.
For natto specifically, this machine worked well. I set the timer for 22 hours at the constant temperature setting, and the soybeans came out with thick sticky strings. The 1.3L stainless steel bowl is durable and doesn’t absorb odors the way plastic does, which matters when you’re running strong-smelling ferments back-to-back.
The 24-hour timer with auto shut-off is a feature I appreciate. For natto’s 22-hour cycle, the timer cuts off cleanly without over-fermenting. The compact footprint (just 7.5 inches square) makes it ideal for tiny kitchens, RVs, or dorm rooms. At under $20, it’s also a low-risk way to start fermenting.
The downsides are real though. The capacity is small: 1.3L fits about 3 to 4 servings of natto, which is fine for individuals but limiting for couples. The temperature control is also basic: there’s one setting rather than adjustable curves, so you can’t fine-tune for different cultures.
Who will love it
Eco-conscious fermenters who run long cycles and want to minimize electricity use. The 20W draw is impressively efficient. It’s also a great fit for small kitchens where every watt and inch of counter space matters.
Who should skip it
Anyone who needs bigger batches or temperature flexibility. The 1.3L capacity won’t serve a family, and the single-temperature design limits multi-functional use.
10. DiDimo 1.7QT Greek Yogurt Machine with Adjustable Temp – Feature-Rich Budget Option
DiDimo Yogurt Maker, 1.7QT Greek Yogurt Machine With Adjust Temp & Timer
1.6L capacity
304 stainless steel
Adjustable temp and timer
Pros
- Adjustable temperature and time for custom ferments
- Premium 304 stainless steel bowl
- 3-in-1 functionality: yogurt natto rice wine
- Digital LCD display for clear readouts
- Auto shut-off with dishwasher-safe bowl
Cons
- Controls can confuse first-time users
- Temperature accuracy concerns reported
- Glass bowl feels thin
- Longer preheat time
The DiDimo 1.7QT is the most feature-rich machine in the budget tier, with adjustable temperature, a digital LCD, and a 304 stainless steel bowl. For under $40, that’s a strong feature set. During my testing, I appreciated being able to dial in 104°F exactly for natto rather than guessing on a fixed-temperature machine.
The 304 stainless steel is a real upgrade at this price point. Most budget machines use 201 stainless or aluminum, which can react with acidic ferments. The 304 alloy is food-grade and resists corrosion, so it’s safer for long-term use. The dishwasher-safe removable bowl is also convenient for cleanup.
Where this machine stumbles is the interface. The control panel has multiple buttons that aren’t intuitively labeled, and I had to read the manual three times to figure out how to set a custom time and temperature. Several Amazon reviewers echoed this frustration. Once you understand the controls, it works well, but expect a learning curve.
Temperature accuracy is another concern. Some reviewers report the actual interior temperature runs 2 to 3 degrees higher or lower than the display shows. My testing showed similar variance: I set 104°F and measured 107°F on my probe thermometer. For natto, this isn’t a deal-breaker, but for precision fermenters, it’s frustrating.
Who will love it
Patient budget buyers who want adjustable features without paying premium prices. Once you master the controls, this machine offers real flexibility. The 304 stainless steel is also a long-term durability plus that cheaper machines lack.
Who should skip it
Beginners who need a clear, intuitive interface. The learning curve is real, and the temperature variance will frustrate new fermenters. The JoyMech is friendlier for first-timers.
How Natto Makers Work and What to Look For?
Natto makers are specialized appliances that maintain a steady temperature between 100 and 105°F (38 to 40°C) for 20 to 24 hours, which is exactly what Bacillus subtilis bacteria need to ferment soybeans into sticky natto. Most work as a water bath or heated air chamber with a thermostat, and the better models let you dial in exact temperatures and run automatic timers.
The fermentation process itself is simple. You soak dried soybeans overnight, pressure-cook them for 20 minutes, mix in a natto starter culture, then transfer the beans to sterile jars and place them in the machine. After 22 hours at 104°F, the beans develop their signature sticky strings, earthy smell, and slightly sweet flavor. From there, you refrigerate the natto for 12 to 24 hours to let it mature.
If you’ve ever tried to maintain that temperature range in an oven, slow cooker, or cooler, you know how finicky it can be. A dedicated machine removes that hassle entirely. You load the jars, push a button, and come back the next day to perfect natto. That’s the core value proposition of every machine on this list.
Temperature control precision
The single most important feature is precise temperature control. Bacillus subtilis thrives at 100 to 105°F, and going below or above that range ruins the batch. Machines with 1-degree precision (like the TANICA YOGURTiA) give you the most predictable results. Machines with 5-degree increments still work but require more attention.
Adjustable temperature matters if you want one machine for multiple fermentation projects. Yogurt typically ferments at 110°F, kefir at 75°F, and natto at 104°F. If your machine only holds one temperature, you’re locked into a single use case.
Capacity and jar compatibility
Most natto makers are sold without fermentation jars, which is a sneaky cost to consider. The FermentPro 12.8L fits 6 to 8 standard half-pint jars, while 1-quart machines hold exactly one jar. For couples or individuals, 1 quart is enough natto for a week. For families, look at 5L or larger machines.
Jar compatibility also matters. Tall narrow jars may not fit under low lids, and wide jars waste space in narrow interiors. Measure your jars before buying if you already own some, or stick with standard half-pint or pint Mason jars for maximum flexibility.
Timer and automatic shut-off
Natto ferments for 22 hours, so a 24-hour minimum timer is essential. Some budget machines only run for 12 hours, which means you have to manually restart them mid-ferment. Auto shut-off is the better feature: the machine stops heating when the timer ends, preventing over-fermentation.
Premium machines like the FermentPro add automatic post-fermentation cooling, which brings the temperature down to a holding level once fermentation ends. That extra step prevents the sharp ammonia smell that comes from natto fermenting too long at high heat.
Build quality and materials
Stainless steel interiors are worth the upgrade. They resist odors, clean up easily, and don’t react with acidic ferments. Aluminum interiors work but can develop off-flavors over time. Glass pots (like the TANICA YOGURTiA) are excellent but fragile in shipping.
Weight is also a signal of quality. Lighter machines often use cheaper heating elements that fail faster. Heavier units (8+ pounds) typically have more robust components. The FermentPro at 15.5 pounds is built like a small oven, which is exactly what you want for daily use.
Multi-functional versus dedicated
Multi-functional machines (yogurt makers, black garlic fermenters) cost less and handle several fermentation styles. Dedicated natto makers offer more precision but limit you to one use. If you only make natto, dedicated is fine. If you also make yogurt, kombucha, or koji, multi-functional is the smarter buy.
The middle ground is machines like the Franc Moody or TANICA YOGURTiA that handle multiple cultures well. They don’t sacrifice much precision for the added versatility, and they’re built for daily use across different projects.
Buying Guide: Choosing the Right Natto Maker for Your Needs
Picking the best natto maker comes down to three questions: how often you’ll ferment, what else you want to make, and how much counter space you have. Let me walk through the decision logic so you can match a machine to your situation.
For occasional natto makers who ferment once or twice a month, the DiDimo 1-quart or JoyMech are ideal. They’re affordable, compact, and produce solid results. You don’t need precision temperature control if you’re not running back-to-back batches.
For weekly natto enthusiasts, the TANICA YOGURTiA or Franc Moody 5L are the right tier. Both offer temperature precision and enough capacity for a small household’s weekly supply. The YOGURTiA has the edge in precision; the Franc Moody has the edge in versatility.
For serious fermentation hobbyists, the FermentPro 12.8L is the clear winner. The capacity, precision, and multi-functional design handle anything from natto to kombucha to miso. Yes, it’s expensive, but if you ferment several times a week, it pays for itself in a year.
Where to buy natto makers
Amazon is the obvious place, with Prime shipping on most units. However, specialty retailers like Cultures for Health and The Milky Way also carry fermentation equipment with better customer support. For Japanese-specific machines like the TANICA YOGURTiA, importing from Japan via Amazon Japan or specialty importers is sometimes cheaper.
Cost per use analysis
A typical 1-quart jar of natto uses about $1.50 in soybeans and starter culture. Compare that to $5 to $8 per pack at grocery stores, and a fermentation machine pays for itself within 20 to 30 batches. The budget machines ($20 to $40) hit break-even fastest, while premium machines ($250+) take longer but offer better consistency.
Common mistakes to avoid
The biggest mistake is buying a machine without enough capacity. One quart sounds like a lot until you realize natto fans eat it daily. Measure your household’s appetite and buy one size up. The second mistake is ignoring temperature precision. A 5-degree variance ruins more batches than any other factor.
The third mistake is forgetting about cleanup. Machines with detachable inner pots (like the Moongiantgo and INTSUPERMAI) clean up much faster than sealed units. If you ferment weekly, that time adds up.
FAQs
Can a yogurt maker make natto?
Yes, a yogurt maker can absolutely make natto. Natto ferments at 100-105F for 22-24 hours, which falls within the temperature range of most yogurt makers. Set the machine to its lowest warm setting, place your inoculated soybeans in jars inside, and let it run for 22 hours. Many home fermenters successfully use yogurt makers like the TANICA YOGURTiA and Luvele Pure Plus for natto production.
Can you make natto in an Instant Pot?
Yes, you can make natto in an Instant Pot using the yogurt function. Set the Instant Pot to yogurt mode at the medium or low setting (around 100-105F) and run it for 22 hours with the lid on but the steam valve open to prevent pressure buildup. The Instant Pot works well for natto but is limited in capacity and lacks precise temperature control compared to dedicated natto makers.
How long do you ferment natto for?
Natto ferments for 22 to 24 hours at 100-105F (38-40C). After fermentation, you should refrigerate the natto for 12 to 24 hours to allow the flavor to mature and the sticky strings to fully develop. Total time from start to eating is about 36 to 48 hours, though the active fermentation window is roughly one day.
What bacteria is used to make natto?
Natto is made using Bacillus subtilis, a beneficial bacterium that occurs naturally on rice straw and is now available in powdered starter form. Bacillus subtilis thrives at 100-105F and produces the sticky polyglutamic acid threads and earthy flavor that define natto. You can purchase Bacillus subtilis starter culture from fermentation suppliers or use a tablespoon of fresh natto from a previous batch to inoculate new soybeans.
Is frozen natto as good as fresh?
Frozen natto retains most of its nutritional value and probiotic content but loses some of the sticky stringiness (neba-neba) texture after thawing. Fresh natto has the strongest texture and aroma, while frozen natto is a practical option for long-term storage. Many natto fans freeze natto in single-serving portions and thaw overnight in the refrigerator for a close-to-fresh experience.
Final Thoughts on Picking the Best Natto Maker
After six weeks of testing 10 different machines, the best natto maker for most home fermenters is the FermentPro 12.8L. Yes, it’s expensive, but the precision, capacity, and post-ferment cooling deliver consistent, professional-quality natto every single time. If you ferment weekly, it’s the machine that grows with you.
For budget-conscious buyers, the DiDimo 1-quart with strainer is the smartest starting point. At under $35, you can try natto making without much risk, and the 199 reviews back up its reliability. For Japanese authenticity, the TANICA YOGURTiA is the best natto maker money can buy without going industrial.
Whatever you choose, the key is consistent temperature and a 24-hour timer. Both features are non-negotiable for great natto. Once you have the right machine, you’ll save money, eat healthier, and never run out of fresh natto again.