How Much Sodium in Homemade Baking Powder? 315 mg/Tsp

A level teaspoon of the 2:1:1 mix holds about 315 mg of sodium. Here are the numbers beside store-bought and low-sodium powders, the math and who should ask a doctor.

We found no source showing that homemade baking powder is lower in sodium or healthier than the store-bought kind, and this page makes no health promise.

Here's the number to keep in mind: the sodium comes from the baking soda, and the baking soda is still in the jar.

This page is a data check, not a test kitchen. Nothing here was baked, tasted or measured by us; every figure is published USDA data or our own arithmetic on it. The same sodium math for baking soda alone lives in how much sodium in baking soda water, and when you can use soda in place of powder is covered in can I use baking soda instead of baking powder. We link instead of repeating their tables.

The Food Science / Lab Kitchen Note

Baking soda is a base. Cream of tartar is an acid. Dry, they sit side by side and do nothing. Add liquid and they react, releasing carbon dioxide gas that puffs up the batter. That's the whole trick of baking powder.

The reaction starts on contact with moisture and keeps going on the counter, which is why the mix is single-acting. Store-bought double-acting powders are built to react in two stages. The homemade mix has only the one. The starch has a smaller job: it soaks up stray moisture and keeps the powder from clumping in the jar.

Now the sodium. USDA FoodData Central lists baking soda at 27,360 mg of sodium per 100 g, which is 273.6 mg per gram. Cream of tartar is potassium bitartrate, and USDA lists it at only 52 mg of sodium per 100 g, with 16,500 mg of potassium. Cornstarch is 9 mg of sodium per 100 g. So the soda supplies almost all the sodium, and the other two add well under 1 mg per teaspoon of mix.

The formula for one level teaspoon of the 2:1:1 mix, our calculation:

• Baking soda: 1/4 tsp, which is 1.15 g (our division of the USDA 4.6 g teaspoon), x 273.6 = about 315 mg
• Cream of tartar: 1/2 tsp, which is 1.5 g (the USDA portion), x 0.52 = about 0.8 mg
• Starch: well under 1 mg
• Total: about 315 mg, which is 13.7% of 2,300 mg

Cross-check by batch weight. King Arthur's page gives 14 g of baking soda for the whole 12-teaspoon batch. At 273.6 mg per gram that is about 3,830 mg, and divided by 12 it's about 319 mg per teaspoon. We round that to about 320, and both methods land near 14% of the daily limit.

The potassium side, by the same math: 1/2 tsp of cream of tartar carries about 248 mg of potassium. DaVita quotes about 495 mg per teaspoon of cream of tartar, which matches.

Sodium per level teaspoon: homemade vs store-bought

This is a comparison of published and calculated data, not a trial of our own. All shares are against the 2,300 mg Daily Value, and every figure is our calculation from the USDA values shown.

Two things stand out. First, the 2:1:1 mix sits below both store-bought entries, but it's in the same range. Homemade isn't dramatically lower. Second, the 1:2 mix carries about 100 mg more sodium per teaspoon than the 2:1:1 mix. Both use the same two-to-one split of acid to soda, and the 2:1:1 version adds a part of starch, so each spoon holds less soda. That reading is ours; none of the pages we opened explains the gap.

The only entry that is actually low is the USDA low-sodium one. Store-bought formulations differ by brand, so the product label wins. We could not confirm the figures for Rumford Reduced Sodium.

One government-affiliated page prints a much lower per-teaspoon figure for the 1:2 mix. It doesn't match the USDA arithmetic or the DaVita panel, which agree with each other, so we don't use it.

What the sources show

We found no clinical trial on the sodium in homemade baking powder, so there is no study size to quote. What we have are two kinds of source, and it helps to read them for what they are.

The first is a database. USDA FoodData Central is the federal nutrient database, and every per-100-gram number above comes from its SR Legacy records: baking soda (FDC 175040), cream of tartar (FDC 175041), the three baking powder entries (FDC 172803, 172804, 172805) and cornstarch (FDC 169698). The records don't print their basis, so the 100 g basis is our assumption, and the spoon weights are USDA household portions. USDA has no entry for potassium bicarbonate.

The second is guidance. The FDA sets the sodium Daily Value at less than 2,300 mg a day, says Americans eat about 3,400 mg on average, and links uncontrolled high blood pressure to heart attack, heart failure, stroke, kidney disease and blindness. A DaVita renal dietitian recipe is informational, not a study, but its panel lists 1,261 mg of sodium per tablespoon, about 420 mg per teaspoon. That matches our 421 mg. On potassium, MedlinePlus (NIH) says that with chronic kidney disease your kidneys may not remove extra potassium from the blood, and that some medicines also raise potassium.

Common mistakes

Mixing the batter and walking away. The mix is single-acting. Once liquid hits it, the gas starts escaping. Have the pan greased and the oven ready before you stir the wet into the dry. Only The Nibble among the pages we opened says this.

Heaping the soda. Too much soda against the acid tastes bitter or soapy. Level every spoon and whisk until the powder is even.

Treating the two homemade ratios as the same. The 2:1:1 mix is about 315 mg of sodium per teaspoon, and the 1:2 mix is about 421 mg. Pick one, and count the figure that matches the one you made.

Substitutes and swaps

The potassium route is a short caution, not a recipe. The two sources we found disagree on the ratio (spoon for spoon in one, about 19 percent more by weight in the other), and neither is an authority. We give no ratio.

Storage and make-ahead

Sources disagree on how long the mix keeps. One page says one month, another says many months, and King Arthur says up to 6 months in an airtight container at room temperature. We found no USDA or FDA source and no freshness test for the homemade mix, so we cite King Arthur's 6 months and say plainly that sources differ.

Make-ahead tip: mix a batch, jar it, and label the date. Give the jar a quick stir before you scoop, and level the spoon every time.

Nutrition note

Values on the recipe card are estimates calculated from typical USDA FoodData Central values for baking soda and cream of tartar, per level teaspoon of mix, not measured. Sodium is about 315 mg, or 13.7% of 2,300 mg. We left the other nutrients off because the USDA cornstarch record has no teaspoon weight, so any starch weight per spoon would be our conversion. The sodium calculation uses 273.6 mg per gram of baking soda, as shown above. For the soda-only math, see how much sodium in baking soda water.