How long doesBaking powderlast in the pantry once opened?
How vague the source is about this one
The source is unusually unsure about this one. Its widest range, the pantry from the day of purchase, runs from 6 months to 18 months, a factor of three between the cautious end and the optimistic one, on a figure most people read as a single number.
Every storage figure the USDA publishes for this item
The USDA rates this item in the pantry and nowhere else, one of 84 foods of the 466 it files that way. Within Baked Goods it is filed under Baking and Cooking.
- Unopened · in the pantry6 months to 18 months
- Once opened · in the pantry3 months to 6 months
Turning the range into a date
Two clocks run on this item: one from the day it went into storage and one from the day the seal broke. Both are listed below, 2 rows in all.
- Unopened · in the pantryUse by6 months to 18 months after the day you bought it
- Once opened · in the pantryUse by3 months to 6 months after the day you opened it
Is this window about safety or about taste?
The answer at the top of this page reads 3 months to 6 months in the pantry once opened. The USDA rating this place at all is the USDA saying Baking powder keeps there, so the figure rates how good it will be. Past it, judge it by look and smell: this window rates how good the food will be, not the day it becomes a hazard.
Every figure assumes the food was sound when you stored it, that your refrigerator holds 40 °F or below and your freezer 0 °F or below, and that the package was handled normally.
It is past the date. Now what?
Say the calculator above puts Baking powder past its 3 months to 6 months in the pantry once opened window. Past that the calendar stops deciding and the food itself does. Mold takes the whole package out rather than the slice it grew on, and so does a musty or old-oil smell in a flour or a mix.
The FoodKeeper entry this page is built from prints storage times and nothing else, so anything past them here is USDA and FSIS guidance rather than a figure from the source. The whole rule, including the cases the source does not cover, is set out under what to do when the date has passed.
Is that a long time?
2 items in the Baked Goods list keep exactly as long as this item, 18 months, so they all share place 20 of 52 rather than being put in an order the data does not support. Among the 244 foods the USDA also gives a pantry figure, it keeps longer than 63% of them.
Items that behave the same way
The 6 items below are the closest match to this item by storage behavior, running 12 months to 24 months and bracketing its 18 months.
- Cake, brownie, bread mixeskeeps exactly as long
- Pastries, danishkeeps 5 days sealed in the pantryup to 14 months in the fridge once opened
- Cocoa and cocoa mixeskeeps 1 year in the pantry once opened
- Garam masalakeeps 1 year in the pantry
- Fruit cakekeeps 6 months sealed in the pantryup to 12 months in the fridge once opened
- Cornstarchkeeps 18 months in the pantry once opened
Products the USDA rates in the same places
This is a common shape of record: 30 of the 466 products are rated in the same places, pantry from the day of purchase and pantry after opening, and 7 of the nine slots are left blank on all of them. Sorted by how close their windows are to this one, the nearest are Lentils, Peas and Marshmallows, and the rest of that group is what the list below draws on. Of the 8 shown, 1 keeps longer than this one. The longest-keeping of them is Cornstarch at 24 months.
- Lentils1 year in the pantry once opened
- Peas1 year in the pantry once opened
- Marshmallows1 month in the pantry once openedup to 1 year sealed in the pantry
- Pudding mixes3 months in the pantry once openedup to 1 year sealed in the pantry
- Soup mixes1 year in the pantry once opened
- Cornstarch18 months in the pantry once opened
- Gelatin3 months in the pantry once openedflavored · up to 12 months sealed in the pantry
- Tapiocas12 months in the pantry once opened
The rest of the Baking and Cooking shelf
The USDA puts this product on the Baking and Cooking shelf together with 34 others, and 19 of them keep longer outside the freezer. The shelf runs from Baking soda at 3 years down to Herbs at 10 days. Nearest this product by window are Cake, Cocoa and cocoa mixes and Garam masala, which is the order the list below is printed in. Across the whole of Baked Goods the same product ranks 20 of 52. The middle of the shelf is Cornstarch, at 24 months. The shelf is the source's own subcategory, Baking and Cooking inside Baked Goods.
- Cake18 months12 months sealed in the pantry
- Cocoa and cocoa mixes1 year1 year in the pantry once opened
- Garam masala1 year1 year in the pantry
- Cornstarch24 months18 months in the pantry once opened
- Flour12 months6 months in the pantry once opened
- Frosting or icing12 months2 weeks in the fridge once opened
- Gelatin12 months3 months in the pantry once opened
- Oils12 months3 months in the pantry once opened
If it has to keep longer than this
If it has to keep longer than 18 months, Baked Goods offers 2 products that hold at least twice as long outside the freezer. The nearest step up is Baking soda at 3 years against this one's 18 months, and the rest are Spice/spices. A short list like this one is itself the finding: the category has few longer options. In the other direction, 19 entries in the category keep half as long or less, Biscuit or pancake mix and Flavored or herb mixes among them.
- Baking soda3 years6 months in the pantry once opened
- Spice/spices3 years2 years in the pantry once opened
The record this page is built from
This page is built from a single FoodKeeper row, record 212 — the source’s own number for it, not a position — one of the 661 rows in the snapshot. That row fills 2 of the nine storage slots with a time, and the binding figure on it is printed by the source in months, which is the unit this page keeps rather than converting it to days. It is filed under Baking and Cooking inside Baked Goods, which is where every shelf comparison on this page comes from.
Where these numbers come from
Every range on this page is published by the USDA FoodKeeper and reproduced unchanged. The multipliers, the rankings, the percentages and the dates are ours, computed from those ranges. Where the source gives a span such as 3 to 5 weeks, comparisons use the upper figure, and the full span is always printed.
Rankings cover only the items the USDA gives a usable figure for, and identical ranges share a place rather than being ordered arbitrarily. Neighbors are chosen by nearest storage time within the same category, never alphabetically: two foods filed next to each other by name usually have nothing to do with each other. The freezer is excluded from ranking because it flattens almost everything.
Where the USDA lists several kinds under one name, they share one page here and every kind keeps its own windows: the source prints them as separate rows, and a page that merged them would be inventing a figure the source never published. Comparisons and the place in the category are computed for the kind the plain name means — the shell egg for eggs, the can for tuna — which is settled name by name rather than by the order the source lists its rows in, and the page names it. Where the plain name means no single kind, the page prints no single figure at all and lists the kinds instead.
Source: USDA FoodKeeper, retrieved 1 September 2026. This site computes every comparison on this page and takes responsibility for it. Found a figure that does not match the source? Tell us on the contact page, with the page and the row — the parsing is mechanical, so a mismatch is our bug and we want it. How the whole site is built, which figures are ours and where the source can be checked is on the method page.
USDA index terms: baking, powder
KeepsUntil is an independent reference built on public USDA data. It is not affiliated with, endorsed by, or connected to the U.S. Department of Agriculture or the Food and Drug Administration. Whether a given window is a safety limit or a quality window is stated on the page that prints it.