At a Glance:

• Baking soda (sodium bicarbonate) is FDA GRAS-approved for food; soda ash (sodium carbonate) has limited food use
• Baking soda has pH 8.3 (weakly alkaline); soda ash has pH 11.3 (strongly alkaline – 1000x more basic)
• Both are sodium-based compounds but chemically distinct (NaHCO₃ vs Na₂CO₃)
• Baking soda is safe for daily consumption; soda ash can damage tissues at concentrated levels
• Food manufacturers use baking soda extensively; soda ash appears only in specific FDA-approved applications

Walk into most kitchens and you’ll find baking soda sitting in the pantry. Ask anyone what it’s for and they’ll probably say baking or maybe cleaning the fridge. But mention “soda ash” and you’ll get blank stares.

Here’s where things get murky: online recipes and food forums sometimes use these terms interchangeably. People see “soda” in both names and assume they’re the same thing. Some old cookbooks mention washing soda (which is soda ash) for food prep. International recipes translated to English don’t always distinguish clearly between the two.

So the question keeps popping up: is soda ash the same as baking soda?

Short answer: No. Not even close.

Long answer: They’re related chemically, but using one in place of the other in food is either ineffective or potentially dangerous depending on the direction you’re swapping. Understanding soda ash vs baking soda matters for anyone working with food—whether you’re developing products, following recipes, or trying to stay compliant with FDA regulations.

Quick Reference: The Key Differences

Property	Baking Soda (Sodium Bicarbonate)	Soda Ash (Sodium Carbonate)
Chemical Formula	NaHCO₃	Na₂CO₃
Common Names	Sodium bicarbonate, bicarb, bicarbonate of soda	Sodium carbonate, washing soda, soda crystals
pH Level	8.3 (weakly alkaline)	11.3 (strongly alkaline)
Alkalinity Strength	Weak base	Strong base (1000x more alkaline than baking soda)
Taste	Slightly salty, neutral	Bitter, caustic
Safety for Ingestion	Safe in typical food amounts	Harmful in concentrated form; damages tissues
FDA Food Status	GRAS (Generally Recognized as Safe)	Limited approval for specific applications only
Primary Food Use	Leavening agent in baking	pH regulator in limited applications
Reaction with Acid	Produces CO₂ (causes rising)	Produces CO₂ but more aggressively
Heat Stability	Decomposes at 50°C to form soda ash + CO₂ + water	Stable at high temperatures
Typical Food Concentration	0.5-2% of flour weight	<0.1% when approved for use
Household Uses	Baking, cleaning, deodorizing, teeth brushing	Laundry, heavy-duty cleaning, water treatment
Industrial Applications	Food/pharma, personal care	Glass manufacturing, chemical processing, detergents

What Makes Them Different: The Chemistry

Both compounds contain sodium, carbon, and oxygen. That’s where the similarity ends.

Baking Soda’s Structure:

Chemical formula: NaHCO₃

One sodium atom, one hydrogen atom, one carbon atom, three oxygen atoms. The hydrogen makes all the difference. When baking soda dissolves in water, it creates a weakly alkaline solution. That hydrogen atom allows baking soda to act as both an acid and a base depending on what it’s mixed with. This property makes it useful for baking—it reacts with acidic ingredients (buttermilk, lemon juice, vinegar) to produce carbon dioxide gas that makes dough rise.

Soda Ash’s Structure:

Chemical formula: Na₂CO₃

Two sodium atoms, one carbon atom, three oxygen atoms. No hydrogen. This creates a much stronger alkaline compound. When soda ash dissolves in water, it forms a highly alkaline solution—pH around 11.3 compared to baking soda’s 8.3.

That pH difference might not sound dramatic. But pH is logarithmic. A difference of 3 pH points means soda ash is about 1000 times more alkaline than baking soda. This is why soda ash can damage mouth and throat tissues while baking soda is safe to brush your teeth with daily.

What Happens When You Heat Baking Soda:

Here’s something interesting: if you heat baking soda to 50°C (122°F) or higher, it breaks down. The hydrogen and some oxygen leave as water vapor and CO₂ gas. What’s left is… soda ash.

So technically, soda ash is what you get when baking soda loses its hydrogen. Some recipes actually call for heating baking soda to create a stronger alkaline ingredient on purpose. But that doesn’t make them interchangeable in most applications.

FDA Regulations: What’s Actually Approved for Food

The US food market operates under FDA oversight. Their position on these two compounds is pretty clear.

Baking Soda (Sodium Bicarbonate)

FDA Status: GRAS – Generally Recognized as Safe

This means decades of safe use have proven baking soda doesn’t present health risks at normal consumption levels. The FDA explicitly approves sodium bicarbonate for:

• Leavening agent in baked goods
• pH control agent
• Processing aid
• Nutrient supplement (sodium source)
• Buffer in beverages

There aren’t strict upper limits on how much baking soda can be in food because normal use levels are self-limiting—too much creates an unpleasant taste. Food manufacturers typically use 0.5-2% of flour weight in baking applications.

Soda Ash (Sodium Carbonate)

FDA Status: GRAS but with significant restrictions

The FDA recognizes sodium carbonate as safe in very specific applications and tiny amounts. It’s approved for:

• Processing cocoa products
• pH adjustment in limited food processing applications
• Water treatment for food manufacturing equipment
• Mineral supplement (in multi-vitamin formulations at low doses)

Notice what’s missing: general baking use. The FDA doesn’t approve soda ash as a leavening agent for home or commercial baking. It’s too alkaline and too harsh.

When soda ash appears in food products, it’s usually at concentrations below 0.1%—much lower than baking soda levels. And it’s typically used in industrial food processing, not in products consumers buy directly.

Why You Can’t Just Swap Them

People sometimes think “they’re both sodium compounds, they’re both alkaline, close enough.” That thinking causes problems.

Replacing Baking Soda with Soda Ash (Don’t Do This)

If you substitute soda ash for baking soda in baking:

• Taste: Bitter, soapy flavor from excessive alkalinity
• Texture: Can break down proteins too aggressively, creating mushy texture
• Safety: At concentrations used for baking soda, soda ash can irritate mouth and stomach
• Rising: Reacts too violently with acids, creating excessive CO₂ too quickly (structure collapses)

Bottom line: soda ash ruins baked goods and potentially harms consumers.

Replacing Soda Ash with Baking Soda (Doesn’t Work)

If you try using baking soda where soda ash is specified (like in certain traditional recipes or industrial processes):

• pH adjustment: Baking soda won’t raise pH sufficiently for applications requiring strong alkalinity
• Processing: Won’t achieve the chemical changes soda ash creates in cocoa processing or other applications
• Quantity: Would need roughly 1000x more baking soda to match soda ash’s alkalinity (completely impractical)

The one exception: if a recipe specifically calls for heating baking soda to convert it to soda ash, that’s fine. But that’s a deliberate chemical conversion, not a substitution.

Legitimate Food Uses: Where Each Belongs

Baking Soda in Food Manufacturing

This is where baking soda shines:

Baking Applications:

• Quick breads and muffins (reacts with acidic ingredients)
• Cakes and cookies (combined with baking powder)
• Pancakes and waffles (leavening and browning)

pH Control:

• Soft drinks (carbonation and pH balance)
• Processed vegetables (maintains color and texture)
• Canned goods (prevents excess acidity)

Texture Modification:

• Pretzels (creates characteristic brown crust when boiled in baking soda water)
• Asian noodles (improves chewiness and color)
• Meat tenderizing (when used in marinades)

Other:

• Antacid in pharmaceuticals
• Cleaning agent for food-contact surfaces
• Deodorizer in food storage

Soda Ash in Food Applications (Limited)

Soda ash appears in fewer food contexts:

Cocoa Processing:

• Dutching (alkalizing cocoa to reduce bitterness and darken color)
• Creates “Dutch-process cocoa” vs natural cocoa
• Soda ash is one of several alkalizing agents used

Industrial Food Processing:

• Water treatment for food manufacturing facilities
• Equipment cleaning between production runs
• pH adjustment in specific chemical processes

Traditional Foods:

• Nixtamalization (treating corn for masa/tortillas—though lime is more common)
• Some Asian noodle recipes (though baking soda increasingly replaces it)

Note: Most legitimate soda ash food uses occur during processing, not as a final ingredient consumers ingest directly.

Safety Considerations

Understanding toxicity differences is crucial for anyone handling these compounds.

Baking Soda Safety:

Pretty hard to hurt yourself with baking soda. People brush their teeth with it daily. It’s in antacids. The biggest risks are:

• Excessive consumption causing stomach upset or alkalosis (rare)
• Interfering with medications if taken in large amounts
• Possible sodium overload for people on sodium-restricted diets

But in normal use—even generous use in cooking—baking soda is safe.

Soda Ash Safety:

This is where caution matters. Soda ash is corrosive at concentrated levels:

• Can burn mouth and esophagus if swallowed concentrated
• Irritates skin (wear gloves when handling)
• Harmful if inhaled as dust
• Eyes especially vulnerable (flush immediately if exposed)

The EPA considers sodium carbonate safe when used according to guidelines, but those guidelines emphasize proper handling and dilution. “Safe pesticide” and “safe food additive” aren’t the same thing. Context matters.

If someone ingests concentrated soda ash:

• Don’t induce vomiting (can cause more damage)
• Give water or milk to dilute
• Seek immediate medical attention

This is why soda ash stays out of kitchens and in laundry rooms.

Conclusion

Soda ash vs baking soda isn’t a matter of personal preference or minor differences—these are chemically distinct compounds with fundamentally different safety profiles and approved applications in the US food market. Baking soda (sodium bicarbonate) is FDA GRAS-approved for extensive food use as a leavening agent, pH adjuster, and processing aid with proven safety at typical consumption levels.

Soda ash (sodium carbonate) is 1000 times more alkaline, approved only for limited industrial food processing applications at very low concentrations, and can cause tissue damage when misused. Food manufacturers, home cooks, and anyone developing food products must recognize that these compounds are not interchangeable despite similar names, with substitution either producing poor results or creating genuine safety hazards depending on the application.

Elchemy supplies food-grade sodium bicarbonate (baking soda) for food manufacturers requiring FDA-compliant ingredients for baking, processing, and formulation applications.