What to Use Instead of Fish Sauce in Kimchi

If you've ever tried making vegan kimchi at home, you've probably hit the same wall I see in every plant-based fermentation forum: what do you use instead of fish sauce? That funky, salty, umami-packed liquid is the backbone of traditional kimchi, and finding a fish sauce substitute in vegan kimchi that doesn't leave your batch tasting flat or weirdly sweet is harder than it sounds.

Here's the thing, it's not just about swapping one salty liquid for another. Fish sauce brings two critical things to the table: sodium for fermentation control and glutamates for that deep savory punch. Most vegan substitutes nail one but miss the other.

As of 2026, the home fermentation community has settled on a handful of reliable options, and the good news is that one of them works beautifully for almost any batch. Let's walk through each one so you can pick the right substitute for your kitchen.

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Quick Answer

Soy sauce or tamari works best as a fish sauce substitute in vegan kimchi. Use one tablespoon per two pounds of cabbage. It delivers the salt and umami levels closest to traditional fish sauce.

For a lower-sodium option, use half soy sauce and half water. Avoid coconut aminos unless you want a noticeably sweeter final batch.

Why Your Fish Sauce Substitute Matters More Than You Think

Most people think fish sauce is just a salt bomb. It's not. It's a precision tool in the fermentation process.

The salt in fish sauce does two jobs at once. First, it draws water out of the cabbage through osmosis, creating the brine that protects against bad bacteria. Second, it slows down the fermentation so the good bacteria (Lactobacillus) develop flavor without things getting mushy or moldy.

Real fish sauce also delivers a specific type of umami. The glutamates in fermented anchovies create that lingering savory taste that makes kimchi so addictive. A vegan substitute needs to hit both the salt concentration and the umami depth.

Get the salt wrong and your kimchi either rots or never ferments. Get the umami wrong and it tastes like spicy salted cabbage, which is not the same thing.

The second factor is fermentation behavior. Some substitutes, like miso, bring their own live cultures to the party. That can speed up fermentation or change the flavor profile in unpredictable ways.

Others, like commercial vegan fish sauces, may contain preservatives that actually slow down or stop fermentation entirely. You're not just seasoning a dish, you're managing a living ecosystem in a jar.

The 6 Best Vegan Fish Sauce Substitutes for Kimchi

Soy Sauce (and Tamari) – The Reliable Workhorse

Soy sauce is the most accessible and predictable substitute on this list. A tablespoon of standard soy sauce contains roughly 2.0 grams of salt, which puts it in the same ballpark as fish sauce per volume. The sodium level is close enough that you can swap one for one in most recipes without adjusting your brine.

The flavor difference is real but manageable. Soy sauce is darker, richer, and has a roasted soybean note that fish sauce doesn't. In a well-spiced kimchi with gochugaru, garlic, and ginger, that difference fades into the background after a few days of fermentation.

Most people who serve vegan kimchi to guests don't notice the swap unless they're told.

Tamari is the gluten-free cousin. It's made without wheat and has a slightly thicker body and more intense soy flavor. For our purposes, it behaves identically to standard soy sauce in terms of salt content and fermentation impact.

If you're cooking for someone with celiac disease or gluten sensitivity, tamari is your best bet.

Best for: Anyone who wants a one-to-one swap with no recipe math, and who doesn't mind a slightly darker final kimchi.

Coconut Aminos – The Low-Sodium Darling

Coconut aminos has become the darling of the Whole30 and paleo crowds, and for good reason. It's soy-free, gluten-free, and contains about 90 percent less sodium than soy sauce. That sounds great until you realize how important salt is to kimchi fermentation.

Here's the problem. A tablespoon of coconut aminos has roughly 0.2 grams of salt. If you use it as a one-to-one swap, your kimchi will be severely undersalted.

The brine won't form properly. Bad bacteria can take hold. And even if fermentation succeeds, the result will be noticeably sweeter than traditional kimchi because coconut aminos contains coconut nectar sugars.

You can fix the salt issue by supplementing with extra salt. But at that point, you're doing more work for a substitute that costs three to four times more than soy sauce. If you're avoiding soy for allergy reasons, tamari is a better choice.

If you need low sodium for medical reasons, use a mix of soy sauce and water to dilute the salt while keeping enough for fermentation.

Best for: People who need a soy-free option and are willing to adjust salt levels manually.

White vs. Red Miso – The Umami Paste Option

Miso is fermented soybean paste, and it brings both salt and live cultures to the party. White miso (shiro miso) is milder, sweeter, and less salty. Red miso (aka miso) is aged longer, darker, and significantly saltier with a more pronounced umami punch.

For kimchi, red miso is the better choice. It delivers a funkier, more complex flavor that gets closer to the fermented anchovy notes you're trying to replace. White miso can work, but it tends to get lost in the spice.

The catch with miso is texture. You're adding a paste, not a liquid. You need to dissolve it in a small amount of warm water before mixing it into your gochugaru paste.

Otherwise, you'll end up with clumps of miso floating in your kimchi brine. The other issue is that miso brings its own fermentation microbes, which can speed up your kimchi fermentation. Keep an eye on it after day two, it may be ready a day earlier than expected.

Best for: Cooks who want maximum umami depth and don't mind adjusting their fermentation timeline.

Shiitake Mushroom Powder – Pure Concentrated Umami

Shiitake mushrooms are naturally high in glutamates. When dried and ground into powder, they become a concentrated umami bomb that rivals fish sauce in intensity. A teaspoon of shiitake powder can deliver the same savory depth as a tablespoon of fish sauce.

The salt issue is real here. Mushroom powder has almost no sodium. You still need to add salt separately to achieve the right brine concentration.

That means you're managing two ingredients instead of one.

Where shiitake powder shines is in combination with another liquid substitute. Add half a teaspoon to your soy sauce or tamari, and you get a flavor profile that comes remarkably close to real fish sauce. The mushroom note is subtle enough that it blends into the kimchi's other flavors after fermentation.

Best for: Anyone who wants to boost the umami of their primary substitute without adding more liquid.

Kelp Granules – The Seaweed Route

Kelp granules are dried and ground seaweed that delivers a briny, oceanic flavor. They're naturally high in iodine and minerals, and they provide a saltiness that comes from potassium and other mineral salts rather than sodium chloride.

The flavor is definitely seaweed-forward. Some people love that in kimchi. Others find it too overt.

Kelp granules work best when blended with another substitute. Try half a teaspoon of kelp granules dissolved in a tablespoon of soy sauce. The seaweed adds the "of the sea" note that fish sauce provides, while the soy sauce handles the salt and body.

One word of caution: kelp is very high in iodine. For most people, that's not a concern. But if someone in your household has thyroid issues or is on a strict iodine-restricted diet, skip this option.

Best for: Cooks who want a briny, ocean-like flavor without using fish.

Commercial Vegan Fish Sauce – The Ready-Made Shortcut

There are now several brands producing bottled vegan fish sauce, typically made from seaweed, soy, or mushroom extracts. These products are formulated specifically to mimic the salt and umami profile of traditional fish sauce.

The quality varies widely between brands. Our research shows that most commercial vegan fish sauces have a salt content close to real fish sauce, which means you can swap them one to one in most recipes. The flavor is usually cleaner and less funky than the real thing, which some people prefer.

The downside is cost. Commercial vegan fish sauce can run three to five times the price of soy sauce per ounce. And some brands contain preservatives like potassium sorbate, which can slow down natural fermentation.

Check the label. If you see preservatives listed, use the product as a seasoning rather than relying on it for fermentation support.

Best for: Anyone who wants a grab-and-go option and doesn't mind paying a premium.

Side-by-Side Comparison: Salt, Umami, and Fermentation Behavior

How Each Substitute Affects Your Kimchi Brine and Fermentation

The brine is where fermentation happens. You need a salt concentration of roughly 2 to 3 percent by weight of your total vegetables and water. That's the sweet spot where Lactobacillus thrives and pathogens like Clostridium botulinum cannot.

When you swap fish sauce for a substitute, you're changing the total salt in that equation. Soy sauce and tamari get you close enough that you don't need to recalculate. Coconut aminos and mushroom powder leave you dangerously undersalted.

Miso lands in between but adds extra microbes that change the timeline.

Here's what happens in practice. If you use coconut aminos without adding extra salt, your kimchi will ferment very quickly, sometimes in just one day, because there isn't enough salt to slow down bacterial activity. The result is a sour, fizzy kimchi that goes mushy within a week.

If you use red miso, the fermentation may finish a full day earlier than expected. Check your jar at day two instead of day three.

The color of your brine changes too. Soy sauce turns the liquid dark brown. White miso leaves it cloudy tan.

Kelp granules give it a greenish tint. None of these affect the final flavor significantly, but they do change the visual presentation. If you're making kimchi for photos or serving it to guests who expect the traditional red-orange look, soy sauce is your safest bet.

Best Substitute for Your Situation: Quick Decision Guide

Let's make this practical. Here's how to pick based on your specific situation.

If you want the simplest swap possible: Use soy sauce or tamari. One tablespoon per two pounds of cabbage. Done.

If you need gluten-free: Use tamari. Same salt levels. Same fermentation behavior.

If you want the deepest umami flavor: Use red miso dissolved in warm water. Watch your fermentation timeline, it will finish faster.

If you're avoiding soy entirely: Use a combination of coconut aminos plus extra salt, or try a commercial vegan fish sauce. For the coconut aminos route, add an extra half teaspoon of salt per tablespoon of aminos to compensate.

If you want to boost the umami of your primary substitute: Add half a teaspoon of shiitake mushroom powder to your soy sauce or tamari.

If you're after that ocean-brine flavor: Blend kelp granules into your soy sauce at a ratio of one teaspoon granules per tablespoon of soy sauce.

How to Adjust Your Recipe for Each Substitute (Ratios and Tips)

Getting the ratio right is the difference between excellent vegan kimchi and a jar you end up throwing away. Here are the specific measurements for each substitute.

For soy sauce or tamari: Use one tablespoon per two pounds of napa cabbage. Reduce any additional salt in your recipe by half a teaspoon to account for the sodium in the soy sauce.

For coconut aminos: Use one and a half tablespoons per two pounds of cabbage, plus add one teaspoon of fine sea salt. This brings the total salt to roughly 2.5 percent of the vegetable weight.

For red miso: Use one heaping tablespoon dissolved in two tablespoons of warm water per two pounds of cabbage. Reduce your recipe's additional salt by one teaspoon.

For shiitake powder: Use one teaspoon of powder dissolved in warm water plus one tablespoon of soy sauce per two pounds of cabbage. Add an extra half teaspoon of salt.

For kelp granules: Use one teaspoon of granules dissolved in warm water plus one tablespoon of soy sauce per two pounds of cabbage. No additional salt needed beyond what's in the soy sauce.

For commercial vegan fish sauce: Follow the one tablespoon per two pounds ratio unless the bottle specifies otherwise.

The key across all options is to taste your gochugaru paste before you mix it with the cabbage. The paste should taste noticeably salty, almost too salty on its own. That's how you know the final kimchi will be properly seasoned after the salt gets diluted by the cabbage's water content during fermentation.

Common Mistakes When Substituting Fish Sauce in Vegan Kimchi

Mistake 1: Using coconut aminos straight up. This is the most common error I see in vegan kimchi forums. People assume all salty liquids are interchangeable. They're not.

Coconut aminos has roughly one-tenth the salt of fish sauce. Your kimchi will ferment too fast, taste flat, and go bad within a week.

Mistake 2: Adding too much miso. Miso is salty, but it's also thick. A little goes a long way. More than one and a half tablespoons per two pounds of cabbage and you'll end up with a paste-like brine that doesn't distribute evenly.

The result is some cabbage pieces that are overly salty and some that are bland.

Mistake 3: Ignoring fermentation speed. Different substitutes change how fast your kimchi ferments. Check your jar at day two instead of day three when using miso. For coconut aminos, check at 24 hours.

For soy sauce, the standard three to five day timeline holds.

Mistake 4: Forgetting to dissolve pastes. Adding miso, shiitake powder, or kelp granules directly into the cabbage mixture guarantees clumps. Always dissolve them in warm water first. A tablespoon of warm liquid per teaspoon of powder is plenty.

Mistake 5: Using iodized salt. This isn't specific to vegan substitutes, but it's worth mentioning. Iodized salt can inhibit fermentation and give your kimchi a metallic taste. Stick with fine sea salt or kosher salt for consistent results.

Frequently Asked Questions

Can I just leave fish sauce out of kimchi entirely?

You can, but the result will be noticeably less flavorful. Kimchi without any fish sauce substitute lacks the savory depth that makes it addictive. The cabbage ferments fine without it, but you'll end up with a flat, one-dimensional taste.

Add a little extra salt to maintain the brine concentration, and consider boosting umami with a small amount of shiitake powder or miso.

Is there a vegan fish sauce that tastes exactly like the real thing?

No commercial vegan fish sauce perfectly replicates the flavor of fermented anchovies. The closest options in our research are products made from seaweed and soy extracts, which deliver the salt and umami levels but miss the funky, fermented fish note. Red miso comes closest in terms of depth and complexity.

How do I know if my substitute has enough salt for safe fermentation?

Use a kitchen scale to weigh your vegetables and water. Aim for a total salt concentration of 2 to 3 percent. For two pounds of napa cabbage (roughly 900 grams), you need 18 to 27 grams of salt total from all sources.

Check the sodium content on your substitute's label to calculate how much you're adding.

Will the color of my kimchi change with different substitutes?

Yes. Soy sauce and tamari darken the brine to a deep brown. Miso makes it cloudy and tan.

Kelp granules add a greenish tint. Coconut aminos leaves it closest to the traditional reddish-orange color. The color change doesn't affect flavor, but it does change the visual presentation.

Can I mix multiple substitutes together?

Absolutely. In fact, blending is often the best approach. Our research shows that a combination of soy sauce and shiitake mushroom powder delivers the closest flavor and salt profile to traditional fish sauce.

Try one tablespoon of soy sauce plus half a teaspoon of shiitake powder per two pounds of cabbage.

The Verdict: Which Substitute Wins for Most People

If you want one answer that works for 90 percent of home cooks, it's soy sauce or tamari. It's cheap, available in every grocery store, and requires zero recipe adjustments. The flavor difference is minimal after fermentation, and the fermentation behavior is identical to traditional fish sauce.

If you're willing to spend a little extra effort for maximum umami, blend soy sauce with shiitake mushroom powder. That combination delivers the closest approximation to real fish sauce in both salt content and savory depth.

Avoid coconut aminos unless you have a specific medical or dietary reason. It introduces too many variables, sweetness, low salt, high cost, for a result that's no better than what you'd get from a simple soy sauce swap.

The best substitute is the one you'll actually use consistently. Pick one, learn how it behaves in your kitchen, and stick with it. Your kimchi will thank you.

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