Unopened Stewart freeze-dried beef liver treats typically have a best-by date 12–18 months from the manufacture date. This is a quality date, not a safety cliff — freeze-dried food does not spoil in the traditional sense. Treats past their best-by date may have reduced aroma but are generally still safe to use.
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Where to find the date on the package
Look on the bottom seam of the resealable pouch or on the back near the nutritional information. Stewart uses a "Best By" stamp format (MM/DD/YY or similar). The date is laser-printed or ink-stamped, occasionally in a slightly different shade that can be hard to read — hold the bag at an angle under good light if you are having trouble finding it.
If you have the tub format rather than the pouch, the date is typically on the bottom of the tub or underneath the lid.
What best-by means vs expiration
"Best By" is a manufacturer's quality guarantee, not a safety cutoff. It means the manufacturer expects the product to be at its peak quality until that date — after which they cannot guarantee the same flavor intensity, aroma strength, or texture. It does not mean the product becomes unsafe to use the next day.
This distinction matters more for freeze-dried food than almost any other category. Unlike fresh food or treats with significant moisture content, freeze-dried food has no water to support microbial growth. The degradation after the best-by date is chemical (fat oxidation causing mild rancidity over a very long period) not microbiological.
Factors that affect actual shelf life
| Factor | Effect on shelf life |
|---|---|
| Storage temperature | Every 10°C (18°F) rise roughly doubles the rate of fat oxidation — cool storage significantly extends quality life |
| Exposure to oxygen | Fat oxidation (rancidity) requires oxygen — minimal air contact preserves quality longer |
| Light exposure | UV and visible light accelerate oxidation — opaque packaging helps; avoid windowsill storage |
| Humidity | The primary quality threat after opening — humidity rehydrates the treat and reduces crispness |
Is it safe to use treats past the date?
For recently expired treats (within 1–3 months of the best-by date, still sealed), almost certainly yes. The aroma may be slightly reduced, but the treats are safe and dogs will still want them. For treats significantly past the date (6+ months after best-by), assess by smell and texture: if there is a rancid or "off" smell when you open the bag, or if the treats look or feel oily in a way that fresh treats do not, discard them. Otherwise, they are usable.
Rancid fat does not cause immediate toxicity in dogs the way some foods do, but chronic feeding of rancid food is not something to make a habit of. A slightly-expired bag used within a few weeks after the date is fine. A significantly-expired bag with obvious rancidity is not worth the risk.
Buying and storing for maximum freshness
When buying online or in stores, check the best-by date if visible. A bag with 12+ months remaining is ideal. Avoid buying close-out stock where treats may have 2–3 months remaining, unless you plan to use the bag within that window.
Store in a cool, dark cabinet. Not in the car trunk, not on the window shelf, not above the stove. The refrigerator extends quality life for opened bags but is not necessary for sealed pouches at normal room temperature. If you buy in bulk, keep the extra pouches in a cool pantry and open only one bag at a time.