How Long Does Baking Soda Last?
Unopened baking soda lasts about 18 months in the pantry, and an opened box is reliable for baking for about 6 months. It stays safe indefinitely; only its rising power fades. Test it with vinegar.
Baking Soda — opened
shelf life- Unopened: 18 months in the pantry
Fridge at 40°F (4°C) or below · freezer at 0°F (−18°C). Freezer times are for best quality; frozen food stays safe longer.
Baking soda is pure sodium bicarbonate, a stable mineral salt that reacts with acids such as buttermilk, yogurt or vinegar to release carbon dioxide. It cannot rot or grow microbes, so it never becomes unsafe to eat. Over time, exposure to humidity and kitchen odors slowly reduces its leavening strength and can taint its flavor.
How to store baking soda
- The cardboard box is not airtight once opened. Pour baking soda into a sealed jar or put the whole box inside a zip-top bag to keep humidity and odors out.
- Keep separate supplies for baking and for deodorizing or cleaning. Soda that has sat open in the fridge has absorbed food odors that will end up in your cookies.
- Store it away from spices, onions and coffee, since absorbing smells is exactly what baking soda does best.
- Test it by dropping a quarter teaspoon into a couple of teaspoons of vinegar or lemon juice. It should foam up instantly and energetically.
How to tell if baking soda has gone bad
- Weak or slow fizzing when mixed with vinegar or lemon juice.
- Hard clumps or a caked block from absorbed moisture.
- A noticeable smell; fresh baking soda is odorless, so any scent is something it absorbed.
- Baked goods that spread flat, fail to brown properly or turn out dense when the recipe relies on soda.
Bacteria that cause food poisoning usually do not change the look, smell or taste of food. Go by the time limits first, and the signs above second.
Baking Soda shelf life chart
| State | Fridge | Freezer | Pantry |
|---|---|---|---|
| Opened | Not recommended | Not recommended | 6 months |
| For baking potency. A box used as a fridge deodorizer should be replaced about every 3 months and never baked with. | |||
| Unopened | Not recommended | Not recommended | 18 months |
| Often fine for longer; test before use. Safe indefinitely, only weaker. | |||
Not safe = perishable: no more than 2 hours at room temperature (1 hour above 90°F / 32°C). Not recommended = possible, but quality suffers or it serves no purpose.
Frequently asked questions
Is it safe to use expired baking soda?
Yes, expired baking soda is safe. Sodium bicarbonate does not spoil or support bacterial growth. The date refers to leavening strength, so old soda may leave baked goods flat. It remains perfectly useful for cleaning, deodorizing and scrubbing even when it is too weak for baking.
How do I know if baking soda is still active?
Mix a quarter teaspoon of baking soda into two or three teaspoons of vinegar. Active soda erupts into foam immediately. If the reaction is sluggish or brief, buy a new box for baking and move the old one to cleaning duty.
Can I bake with the box of baking soda from my fridge?
No, it is not a good idea. It is not unsafe, but a box left open as a deodorizer has absorbed moisture and odors from fish, onions and leftovers, and it will be weaker and can flavor your baking. Keep a separate sealed supply for recipes.
Does baking soda last longer than baking powder?
Yes. Baking soda is a single stable compound and only reacts when it meets an acid, so it keeps its strength for a year or more. Baking powder already contains acid and begins to degrade as soon as humidity reaches it.
Related foods
| Food | Fridge | Freezer | Pantry |
|---|---|---|---|
| Baking Powder Opened |
Not recommended | Not recommended | 3–6 months |
| Cornstarch Dry (uncooked) |
Not recommended | Not recommended | Indefinitely |
| Flour Dry (uncooked) |
1 year | 1–2 years | 6–12 months |
| Salt Opened |
Not recommended | Not recommended | Indefinitely |
| Buttermilk Opened |
1–2 weeks | 3 months | Not safe |
| Vinegar Opened |
Not recommended | Not recommended | Indefinitely |
More baking staples: Brown Sugar, Cornmeal, Sugar, Whole Wheat Flour, Yeast.
Reviewed 2026-09-20. Times follow published USDA FoodKeeper / FSIS, FDA and CDC storage guidance; where sources differ we use the shorter time. How we compile this data.