Fried tortilla chips are about a quarter oil, so their shelf life ends two ways: they go stale, pulling moisture from the air and losing their snap, and their oil goes rancid, slowly, faster with air, light and warmth. A sealed, lined bag slows both; an opened bag is a matter of days. Neither makes chips unsafe, so the date is a quality date. A lab test called peroxide value tracks the oil's early oxidation before a taster can tell. In the example below, an Arizona chip maker's bags passed every test through day 98, and they say best by 73 days, a 25% margin. Below is what ends a chip's shelf life, the study, storage, the date, and a free template.
The short version
- Chips go stale from moisture and rancid from oxidized oil.
- A sealed, lined bag slows both; an open bag lasts days.
- Light and warmth speed rancidity.
- Peroxide value tracks the oil before a taster notices.
- Run a real-time study and leave a margin.
- Print a quality date: "Best by".
- TaroStack gives every batch its date from the shelf life you set. More below.
What ends its shelf life
| What ends it | What happens | What slows it |
|---|---|---|
| Staling | Chips pull moisture and lose their crunch | A sealed, lined bag; a good seal on every bag |
| Rancid oil | The oil oxidizes and tastes stale or painty | Fresh fryer oil; bags out of light and heat |
| Breakage | Chips crush in the case | Bags filled with air; cases stacked right |
| Opening | Air and humidity reach them | "Best within a week of opening" |
Bags and the fryer oil schedule are in tortilla chips business plan, and the salsa sold beside them keeps as in salsa shelf life.
How it's stored
| Stored | In the example's tests | On the label |
|---|---|---|
| Sealed bag, room temperature, out of light | Passed every test through day 98 | Best by 10 weeks |
| Opened bag | Not part of the study | "Best within a week of opening" |
| Sealed bag in a sunny window | Not part of the study | Shorter; kept out of display windows |
The light line is the maker's caution: oil oxidizes faster in light, so grocers are asked to keep the bags off sunny shelves.
An example: a shelf life study
Sol de Mesa Chips, the made-up tortilla chip maker in Tucson, Arizona, I use in these examples, kept sealed bags from one frying day in a dark storeroom and opened two at each pull, one for tasting and one for the lab:
| Test | Pass if | Day 0 | Day 28 | Day 56 | Day 84 | Day 98 | Day 112 |
|---|---|---|---|---|---|---|---|
| Flavor score, 1 to 9 | at least 6 | 9 | 8 | 7 | 7 | 6 | 5 |
| Crispness score, 1 to 9 | at least 6 | 9 | 9 | 8 | 7 | 6 | 5 |
| Peroxide value, meq/kg | at most 10 | 1 | 2.4 | 4.6 | 7.1 | 8.9 | 11.8 |
| All pass? | Pass | Pass | Pass | Pass | Pass | Fail |
Everything passed through day 98; at day 112 the peroxide value passed the limit and the chips tasted stale. Taking a 25% margin off day 98 gives 73 days, about ten weeks. How the pulls and margin are planned is in shelf life testing.
The date on the label
Tortilla chips carry a quality date, "Best by". In California, food made from July 1, 2026 that shows a date uses "BEST if Used by" for quality or "USE by" for safety, in sell by date law, and how to write the date is in best by date format.
Get the template
Download the tortilla chips shelf life study template. One sheet: the product, the lot tested, the day it was made, how it's stored and the margin to leave; then each test with its limit and the result at each pull. It marks each pull pass or fail, finds the last day everything passed, takes the margin off, and gives the shelf life for the label and the date for a batch made today. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.
Where this stops working
Ten-week chips move fast enough, but two flavors fried on different days, ten grocers, and bags that sat on a sunny shelf are where a stale bag comes back.
How TaroStack does it
TaroStack gives every batch its date from the shelf life you set, and sends the oldest out first.
Dates from the shelf life. Each bag of chips carries its shelf life in days, and each batch's lot gets its production date and the date that follows from it.
First-expired-first-out. Orders take the oldest lots first by default, and a grocer can be set to take only stock with enough days left.
What's coming up. A forecast shows what will expire unsold and what it costs, and anything thrown out is recorded with its reason, expired or spoiled, so waste shows by item.
| The job | Spreadsheet | In TaroStack |
|---|---|---|
| The date on a batch | Worked out by hand | From the shelf life, on the lot |
| Which batch goes out first | Dates on tape | First-expired-first-out |
| Stock with enough days for a grocer | Checked by hand | The customer's shelf-life rule |
| What expired last month | Not counted | Waste by reason |
Lots, dates, first-expired-first-out and the expiry forecast are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.