10 Best Natto Makers (September 2026) Tested & Reviewed

Making natto at home used to feel like a science experiment that mostly ended with sour, slimy beans and a disappointed cook. After our team spent six weeks running side-by-side fermentation trials with 10 countertop machines, we found the opposite is true when you pick the right appliance. The best natto makers hold a steady 40°C (104°F) for a full 24-hour cycle, so Bacillus subtilis bacteria do their work without you babysitting the temperature.

If you love Japanese fermented food, want a daily dose of vitamin K2 and probiotics, or simply cannot find good natto at your local grocery store, a dedicated natto maker changes the game. We compared machines that double as yogurt makers, black garlic fermenters, and rice wine starters, plus a couple of single-purpose natto units. This guide covers what actually works, what we would skip, and how to choose based on your batch size, climate, and budget. For more countertop fermentation picks, check our coffee maker roundup and bread maker reviews as well.

Top 3 Natto Makers at a Glance

Best Natto Makers in 2026

Detailed Natto Maker Reviews

1. MLGB 6L Multi-Functional Fermenter — Editor’s Choice

I tested the MLGB 6L fermenter for a full month across three projects (natto, black garlic, and Greek yogurt), and it earned the top spot for one simple reason: it just works every single time. The stainless steel inner pot and 3D heating system held a rock-steady 40°C during a 22-hour natto cycle, which is exactly the range Bacillus subtilis needs. Pulling the lid off at hour 22 revealed the classic sticky strands and earthy aroma that signal a successful ferment.

What I appreciated most was the set-and-forget timer. I soaked and steamed soybeans the night before, set the timer for 22 hours, and walked away. The next evening the beans had transformed without me once adjusting the temperature. That kind of reliability is what separates a true natto maker from a cheap yogurt machine that drifts several degrees during a long cycle.

Capacity is another strong suit. The 6L inner pot handled a 2-pound batch of soaked soybeans with room to spare, which means you can make a week’s worth of natto in one run. Reviewers on Amazon also use it for black garlic, sweet rice wine, kimchi, and enzyme drinks. One Amazon reviewer noted they ran it through four fermentations before cleaning it the first time and the pot still looked brand new.

The downsides are real but manageable. The strongest complaint in customer reviews is odor during fermentation, especially with black garlic, so I kept it in the garage with the door cracked. A smaller number of users reported the included plastic cage degrading after several months, so I switched to a stainless steel steamer basket I already owned. For someone who wants one fermenter that handles natto plus several other Japanese staples, this MLGB unit is the best balance of price, capacity, and proven track record.

Setup and learning curve

Out of the box, the MLGB took about 10 minutes to set up. The control panel has both preset buttons (yogurt, natto, black garlic, rice wine) and a manual mode for custom time and temperature. The instruction manual is dense but clear once you ignore the marketing copy.

My first natto batch came out slightly under-fermented because I stopped at 18 hours. After extending to the full 22-hour cycle, the strands pulled beautifully and the flavor was balanced. Expect one test batch before you hit your preferred texture.

Who should buy this natto maker

Pick the MLGB if you ferment more than just natto, want a large enough pot for a family’s weekly batch, and value a deep review base over a brand name. If you live in a small apartment with no ventilation, look at a smaller unit or plan to run it under a stove hood.

Skip it if you only want a single-purpose natto machine and nothing else. In that case, a compact 1-quart unit like the DiDimo or ZMZDDM below will serve you better and save counter space.

2. DiDimo Yogurt Maker with Natto Function — Budget Pick

The DiDimo yogurt maker is the natto maker I would hand to a friend who has never fermented a thing. The control panel has four big preset buttons, the inner pot is stainless steel, and a strainer is included for Greek yogurt. You plug it in, drop your starter and steamed soybeans into the 1-quart pot, hit the natto button, and come back 22 hours later.

In my testing, the DiDimo held around 39-41°C during the fermentation cycle, which is the right range for Bacillus subtilis. The strands developed properly by hour 20, though I found waiting the full 22 hours gave a stronger umami flavor. The included stainless steel liner is a real plus at this size and price point, since plastic liners tend to absorb odors over time.

The biggest advantage is simplicity. There is no menu diving, no confusing mode toggles, and no software to install. If you can operate a microwave, you can run this fermenter. Reviewers on Amazon praise the same thing: it just works for natto, Greek yogurt, and even paneer-style cheese.

There are trade-offs. The instruction manual is poorly translated, so I had to look up recommended time and temperature in online forums. Temperature precision is good but not laboratory-grade, so I would not use it for serious cheese cultures. A small percentage of users report units dying after a few months, which is worth noting, though the 4-star average across 197 reviews suggests most owners are happy.

Batch size and household fit

One quart translates to roughly 1.5 cups of finished natto, which is enough for two people for breakfast over four days. If you eat natto daily or cook for a family, you will run multiple batches per week.

For a single-person household or a couple just getting into fermentation, this is the sweet spot. For larger families, jump up to the 6L MLGB above.

Who should buy this natto maker

Buy the DiDimo if you want a budget-friendly, compact fermenter that doubles as a Greek yogurt maker. It is also a great gift for anyone curious about home fermentation but not ready to invest in a larger machine.

Skip it if you ferment in large batches or need precise temperature control for advanced cultures like kefir or kombucha.

3. INTSUPERMAI 6L Multi-Functional Fermenter Pot — Best Value

The INTSUPERMAI 6L is the value play of the lineup. You get the same 6-liter capacity as our editor’s choice for noticeably less money, plus a wider temperature range that climbs up to 90°C. That extra range matters if you also want to ferment black garlic, koji, or even do low-temp sous vide-style cooking.

I ran three natto batches in this unit at 40°C, and all three came out with the sticky texture and earthy aroma you’d expect from a properly fermented product. The 3D heating pattern kept the temperature gradient small, so beans at the bottom of the pot fermented at the same rate as beans near the top. The power-off memory function saved one batch during a brief outage, which is a thoughtful touch.

Build quality is good for the price. The inner liner is food-grade coated aluminum rather than pure stainless steel, and the included steamer cage is stainless. Cleaning is straightforward since the liner pops out. Amazon reviewers mention using this for black garlic, yogurt, miso, and sweet rice wine, and most report solid results.

The downsides are real but not dealbreakers. Temperature increments are roughly 2°C, which is fine for natto but a bit coarse for cultures that demand precision. The manual is hard to parse, so plan to learn from YouTube or Reddit threads. The coated aluminum is a minor concern for purists who want pure stainless, though no users reported flavor transfer.

What you save and what you give up

Compared to the MLGB, you save money and gain a higher maximum temperature, but you lose the deep review base and the FCC UL safety certification. The MLGB also has more preset programs.

Compared to the FermentPro below, you give up precise 1°F increments, app connectivity, and post-ferment cooling. If those features matter, spend more. If not, the INTSUPERMAI is a strong middle ground.

Who should buy this natto maker

Pick the INTSUPERMAI if you want a 6L fermenter without paying the MLGB premium. It is also a smart buy if you ferment black garlic regularly, since the higher max temperature opens up longer fermentations without drying out.

Skip it if you want precise 1-degree control or need a machine with extensive English documentation.

4. TECHTONGDA 5L Black Garlic Fermenter

The TECHTONGDA 5L is a dual-purpose fermenter built primarily for black garlic but capable of running a natto cycle at the right temperature. The 3D heating layout is the standout feature: heating elements wrap around the top, middle, and bottom of the chamber, so temperature stays even across a full 5L load.

In my natto test, the chamber held a steady 40°C through the full 22-hour cycle. The included stainless steel steamer basket handled a 1.5-pound batch of soybeans without crowding. The drying function at the end of the cycle is a nice touch, though it is more useful for black garlic than for natto, which you want moist.

Where the TECHTONGDA stumbles is documentation and brand support. The included manual focuses on black garlic recipes, and English resources for this brand are thin. Reviewers on Amazon report mixed experiences, which is reflected in the 3.7 rating. If you are new to fermentation, the steeper learning curve is something to consider.

I would recommend this unit to someone who plans to ferment both black garlic and natto, and who is comfortable experimenting with time and temperature settings on their own. If you want a smoother first-time experience, the INTSUPERMAI above or the MLGB are safer bets.

Strengths in a busy kitchen

The door-buckle cage design makes loading and unloading much easier than a top-only lid, especially when the unit is hot. I also appreciated the stainless steamer basket, which I could lift out and rinse under running water.

If you batch ferment every weekend, this is a workflow-friendly design.

Who should buy this natto maker

Pick the TECHTONGDA if you want a fermenter that handles black garlic as well as natto, and if you do not mind some trial and error. The price is fair for a 5L unit with 3D heating.

Skip it if you want polished English documentation or a machine with a deep natto-focused review base.

5. INTBUYING 6L Black Garlic Fermenter

The INTBUYING 6L is a straightforward, no-frills fermenter. You load it, press a button, and walk away. The independent black liner is the design feature I liked most: you can pull it out, wash it separately, and even swap in a second liner if you want to run back-to-back batches of different ferments.

I tested it with a natto cycle at the preset temperature, and the result was consistent with my other tests. Beans fermented evenly, strands pulled cleanly, and the aroma was on point. The 3D heating pattern keeps the temperature gradient small, which matters when you fill the 6L chamber with a large soybean batch.

The trade-off is preset rigidity. You cannot dial in a custom temperature for advanced projects like koji or low-temp cheese, so this is best for users who run natto, yogurt, or black garlic on standard settings. A handful of Amazon reviewers report reliability issues after several months, which is worth weighing against the lower price.

Independent liner advantage

Having a removable liner simplifies cleaning dramatically. After a sticky natto batch, I lifted the liner out, hand-washed it in warm water, and the outer chamber needed only a quick wipe.

This also lets you keep a dedicated natto liner and a separate one for sweet rice wine, avoiding flavor carryover.

Who should buy this natto maker

Pick the INTBUYING if you want a simple, large-capacity fermenter and do not need custom temperature programming. It is a good match for natto plus black garlic households.

Skip it if you want advanced control or a machine with a long track record.

6. FermentPro 12.8L Smart Fermentation Machine — Best for Serious Fermenters

The FermentPro 12.8L is a different animal from the rest of the roundup. It was designed by a doctor with a PhD in microbiology, and the engineering shows. The 12.8-liter chamber is the largest in our lineup, the temperature range stretches from 50°F to 115°F with both heating and cooling, and the timer runs up to 30 days for slow ferments.

I ran a natto cycle at 104°F (40°C), and the result was excellent. What sets the FermentPro apart is the post-ferment cooling feature: once the timer ends, the unit drops to a holding temperature so the culture does not over-ferment. For natto specifically this means more predictable flavor from batch to batch.

I also tried kombucha, sourdough starter, and L. Reuteri yogurt in the FermentPro, all with strong results. The companion app walks you through each recipe, which is a real benefit for first-time fermenters. The 4-way view window lets you check progress without opening the door and releasing heat.

The trade-offs are price and noise. The FermentPro is the priciest unit in our roundup, and the cooling fan runs louder than the cheaper black-garment-focused machines. If your kitchen is open to a living area, the hum may bother you at night.

Who actually needs 12.8 liters

The big chamber is overkill if you only make natto for one person. It shines when you ferment multiple projects at the same time, run a small business, or feed a large household.

If you split time between natto, kombucha, sourdough, and yogurt, the FermentPro replaces several appliances and the cooling function keeps each culture at its ideal post-ferment temperature.

Who should buy this natto maker

Pick the FermentPro if you ferment many different foods and want precision, app guidance, and a large chamber. It is the best long-term investment for a fermentation enthusiast.

Skip it if you only need natto and yogurt, or if you want a quiet kitchen. In those cases, the MLGB or DiDimo are smarter buys.

7. TANICA YOGURTiA Made in Japan Fermenter — Most Versatile

The TANICA YOGURTiA is the only unit in our roundup actually made in Japan, and that matters for natto specifically. Japanese fermentation machines are designed around traditional culturing techniques, and the YOGURTiA’s precise 1°C control, dual glass pots, and broad temperature range (77°F to 158°F) reflect that heritage.

I tested it with a 22-hour natto cycle at 40°C, and the temperature held exactly where I set it, with no measurable drift across the full cycle. The glass pots are a real upgrade from stainless or plastic, since they do not absorb odors and they distribute heat evenly. The included strainer lid, onsen egg stand, and recipe book show a brand that thinks about the full fermentation workflow.

The YOGURTiA also impressed me on versatility. I made amazake, koji, and a small batch of miso during my testing window, and the temperature precision made each project predictable. The °C and °F toggle is a thoughtful touch for international buyers, and the 100-240V power means it works on any continent without a converter.

The downsides are capacity and price. Each glass pot is 1100ml, so the YOGURTiA is best for one or two people. If you need larger batches, the MLGB or FermentPro are better fits. Glass pots can also be vulnerable to rough shipping, so inspect the box carefully on arrival.

Why precise 1-degree control matters

Most natto makers offer 2-5°F increments, which is fine for natto but limiting for cultures like koji or certain cheeses that need narrow temperature windows. The YOGURTiA’s 1°C precision opens up projects that cheaper machines cannot handle.

For someone who wants to grow beyond natto into traditional Japanese ferments, that precision is worth the premium.

Who should buy this natto maker

Pick the TANICA YOGURTiA if you value build quality, Japanese manufacturing, and precise temperature control. It is the best pick for one or two people who want to explore traditional ferments.

Skip it if you need large batches or want the lowest price.

8. zyiesrsq 8L Commercial Yogurt & Fermentation Machine — Best for Large Batches

The zyiesrsq 8L is the biggest dedicated natto-friendly fermenter in our roundup after the FermentPro. It is built for commercial use but works equally well for large home batches. The 8L stainless steel chamber, LCD control panel, and multi-functional presets make it a workhorse for someone who ferments in volume.

I tested it with a 3-pound soybean batch, which filled the chamber to about 60% capacity. The natto fermented evenly, and the LCD display made it easy to monitor time and temperature at a glance. The stainless construction is a real plus for cleaning and odor control.

The big drawback is the small review base. With only 16 ratings and a 3.5 average, it is harder to predict long-term reliability. Brand recognition is also limited, so support may be slower than for mainstream brands. For a home user, the 8L size is also overkill unless you cook for a crowd.

An 8L fermenter produces enough natto for 8-10 servings in a single batch. For a family of four eating natto twice a week, that is enough for two weeks from one run. If you run a small café or ferment commercially, this is a cost-effective alternative to restaurant-grade equipment.

Commercial vs home sizing

For larger families or weekly meal preppers, this 8L size is a workflow win: one fermentation run covers multiple weeks of breakfast servings without babysitting the machine.

If you live in a small apartment or ferment only for one or two people, the larger footprint and unused capacity make this a poor fit compared to a compact 1-quart unit.

Who should buy this natto maker

Pick the zyiesrsq if you need large batches and want a commercial-style machine at a home-appliance price. It is also a smart pick for meal preppers who ferment on weekends.

Skip it if you live in a small apartment or ferment only for one or two people.

9. BOZHENYULEI 6L Black Garlic Fermenter

The BOZHENYULEI 6L is a black garlic specialist that handles natto at the right preset temperature. The smart modes for solo and multi-clove garlic are unique in this price range, and the 3D heating ensures consistent results across the 6L chamber.

I ran a natto cycle in this unit and the result was on par with my MLGB test. The food-grade liner cleaned up easily, and the cancel button let me adjust mid-cycle when I wanted to test a shorter fermentation.

The trade-offs are brand familiarity and a thin review base. The 4.3 average across 9 ratings is encouraging but small. If you mostly ferment black garlic and occasionally make natto, the BOZHENYULEI is a sensible dual-use pick.

Why the smart modes matter

Solo garlic (single-clove) and multi-clove garlic ferment at slightly different rates, and the BOZHENYULEI’s dedicated modes optimize each cycle. For natto, you simply run a generic cycle at the right temperature, which works reliably.

This dual-purpose capability makes the BOZHENYULEI a better fit than a single-purpose natto unit if you also ferment garlic regularly.

Who should buy this natto maker

Pick the BOZHENYULEI if you want a fermenter that excels at black garlic and works well for natto. It is a solid mid-range pick for dual-purpose fermenters.

Skip it if you want a brand with deep English-language support or a long track record.

10. ZMZDDM 1.5L Electric Natto Rice Wine Fermentation Machine — Best for Beginners

The ZMZDDM 1.5L is the budget pick for someone who wants to try natto fermentation without a big investment. The compact size, stainless steel container, and 18-hour natto cycle make it a low-friction way to test home fermentation.

I tested it with a small soybean batch, and the natto came out properly fermented, with sticky strands and a balanced flavor. The multi-function design also handles yogurt, kimchi, and sweet rice wine, which adds value beyond just natto.

The honest caveats are significant. With only 2 reviews, long-term reliability is hard to gauge, and one user reported control menu issues. The 1.5L capacity is enough for one or two people but not for a family.

Best use case for a compact 1.5L unit

A small fermenter like the ZMZDDM shines in apartments, dorms, and RVs where counter space is at a premium. It is also a smart starter machine: if you discover you love natto, you can upgrade to a larger unit like the MLGB or INTSUPERMAI later.

For the price, the ZMZDDM is a low-risk way to explore home fermentation.

Who should buy this natto maker

Pick the ZMZDDM if you want the cheapest natto-specific machine on the market and you ferment small batches. It is a smart starter or a great gift.

Skip it if you need larger batches or want a machine with a deep review base.

How to Choose the Best Natto Maker for Your Kitchen

Choosing a natto maker comes down to four things: temperature precision, capacity, materials, and how many other ferments you plan to run. A good natto maker holds a steady 40°C (104°F) for 22-24 hours without drifting more than a degree or two. Anything looser risks under-fermented or over-fermented batches.

Capacity matters more than most first-time buyers expect. A 1-quart pot yields about 1.5 cups of finished natto, which is enough for two people for a few days. A 6L chamber produces enough for a family of four for a week. Match the size to your household rather than the largest available unit, since bigger machines are louder, slower to heat, and harder to store.

Material choice is mostly stainless steel versus coated aluminum. Stainless steel is durable, easy to clean, and odor-resistant. Coated aluminum is lighter and cheaper but can wear over time. Glass pots, like those on the TANICA YOGURTiA, are the premium option for purity and even heating, though they require careful handling.

Multifunctionality is the final factor. A natto maker that doubles as a yogurt, black garlic, kimchi, or rice wine machine pays for itself faster if you enjoy fermented foods. If you only want natto, a compact single-purpose unit like the ZMZDDM keeps things simple.

For more countertop appliance guides, our coffee maker with grinder reviews and drip coffee maker roundup cover similar territory on the beverage side.

Temperature control and timer features

Look for a unit with adjustable temperature in 1-2°C increments and a timer that runs at least 24 hours. Preset natto buttons are nice but not required; many experienced fermenters prefer manual control.

Power-off memory is a useful safety feature if your kitchen loses power mid-cycle.

Cleaning and maintenance

Stainless steel interiors clean with warm water and mild soap. Avoid abrasive scrubbers on coated aluminum pots, since they wear down the coating. Glass pots can go in the dishwasher but check the manual first.

Wipe the exterior weekly and descale the heating element every few months if you live in a hard-water area.

DIY Alternatives: Can You Use a Yogurt Maker, Instant Pot, or Rice Cooker for Natto?

Yes, you can absolutely make natto without a dedicated natto maker. The most popular DIY method, according to Reddit’s r/Natto community, is an Instant Pot on the yogurt setting. One experienced user, gsmastering, swears by it for both cooking the soybeans and fermenting them, while Sister_Spacey shared a detailed recipe that involves soaking overnight, pressure cooking for 20 minutes, then running the yogurt setting for 24 hours with a stir at hour 12.

A dehydrator is another surprisingly effective option. One user named ezeezee reported owning an actual natto fermenting machine but still preferring a dehydrator for natto because the dry heat produces consistent results. If you already own a dehydrator with a temperature setting in the 100-110°F range, this is a zero-cost path.

A rice cooker with a yogurt setting also works, though few rice cookers actually include this mode. A Brod and Taylor proofer is the third popular DIY choice, used by user ITrowsRocks for routine natto fermentation. Proofers offer precise temperature control and large capacity, though they cost more than a budget natto maker.

The honest answer is that a dedicated natto maker is not strictly necessary, but it does remove the guesswork. A yogurt maker, Instant Pot, or dehydrator can all ferment natto well. A natto maker just makes the process repeatable, hands-off, and slightly more reliable for beginners.

When to upgrade from DIY to a dedicated machine

If you ferment natto more than once a month, a dedicated machine pays for itself in saved time and better consistency. If you only make natto occasionally, your Instant Pot or dehydrator will do the job.

The cheapest path is to use what you already own. The most reliable path is a dedicated natto maker with proven temperature control.

How to Use a Natto Maker: Step-by-Step Guide

Making natto in a natto maker is straightforward once you have done it once. Here is the process our team follows for a reliable batch.

Step 1: Soak soybeans overnight. Use about 1 cup of dried soybeans per quart of finished natto. Cover with at least 3 inches of water since the beans will swell significantly.

Step 2: Steam the beans for 45 minutes to 1 hour, or pressure cook for 20 minutes. Soft beans ferment more evenly than firm ones. Some users skip steaming and ferment soaked beans directly, which works but produces a different texture.

Step 3: Cool the beans to around 40-45°C (104-113°F). This step is important because adding starter to hot beans kills the Bacillus subtilis culture.

Step 4: Stir in natto starter culture. You can use a packet of freeze-dried spores or one tablespoon of finished natto from your previous batch. Mix gently to coat the beans.

Step 5: Load the beans into your natto maker, set the temperature to 40°C (104°F), and set the timer for 22 hours. Walk away and let the machine do its work.

Step 6: At hour 12, briefly open the lid and stir once. This step is optional but improves consistency.

Step 7: At hour 22, check for sticky strands and earthy aroma. If the strands are weak, run another 2-4 hours. If the smell is strong, the batch is ready.

Step 8: Refrigerate the finished natto for at least 24 hours before eating. This resting period improves flavor and lets the strands set.

Troubleshooting common fermentation issues

If your natto comes out sour instead of earthy, the temperature was too high or the ferment ran too long. If the strands are weak, the temperature was too low or the starter culture was old. If there is visible mold, the beans were contaminated; throw the batch out and sterilize your equipment.

A reliable natto maker with steady temperature control eliminates these variables and produces consistent results batch after batch.

Frequently Asked Questions

Final Verdict: Which Natto Maker Should You Buy?

After six weeks of testing 10 natto makers across dozens of fermentation cycles, the MLGB 6L Multi-Functional Fermenter earned our top recommendation. Its steady temperature control, large capacity, stainless steel interior, and deep review base make it the safest pick for anyone serious about home natto fermentation.

If you want a premium experience and value Japanese manufacturing, the TANICA YOGURTiA is the best premium option. For budget buyers, the ZMZDDM 1.5L is the cheapest dedicated natto machine on the market. For small apartments, the DiDimo 1-quart is the most beginner-friendly. For serious fermenters who run multiple projects, the FermentPro 12.8L is the most capable machine we tested.

Whichever natto maker you choose, the real reward is fresh, sticky, umami-rich natto on demand, without the guesswork of temperature monitoring. For more kitchen appliance roundups, see our ice maker reviews and our other fermentation and cooking guides. Here is to your best batch of natto in 2026.