There's a bag at the back of the freezer with a date written in marker that has half rubbed off. You think it's from August. It might be from July. Either way, it's been sitting behind the newer bags this whole time, which is exactly the wrong way round.
A milk stash runs on two things: knowing when each bag has to be used, and using the oldest one first. Write the pump date on every bag, keep fridge milk for up to 4 days and frozen milk for about 6 months (up to 12 is acceptable), and always reach for the oldest bag.1 Everything else is about making those two habits easy at 3 AM.
How long does breast milk last in the fridge and freezer?
These are the CDC's storage times for freshly pumped milk:1
| Where | How long |
|---|---|
| Room temperature (77°F / 25°C or colder) | Up to 4 hours |
| Fridge | Up to 4 days |
| Freezer | About 6 months is best, up to 12 months is acceptable |
| Thawed in the fridge | Within 24 hours of fully thawing |
| Thawed and brought to room temperature or warmed | Within 2 hours |
| Left over after a feed | Within 2 hours, then thrown away |
Thawed milk never goes back in the freezer.1
The clock that matters for thawed milk starts when it finishes thawing, not when you pumped it. That's the one parents lose track of most, because the bag's original date no longer tells you anything useful.
Keeping the stash in order
Label every bag with the date it was pumped. The CDC also suggests thawing the oldest milk first.1
Freeze bags flat. They stack like files, and you can read every date without digging through a frozen pile.
Splitting a pump into smaller bags cuts waste. A 60 ml bag that covers a top-up beats thawing 150 ml and pouring half of it away two hours later.
Keep one running total somewhere. "How much do we actually have?" always comes up right before a return to work or the first night someone else does bottles.
Four ways to track a stash
None of these is wrong. They just break at different points.
Paper, a whiteboard, or the marker on the bag
Free, instant, and nobody needs an app. A whiteboard on the freezer door works well when one person handles all the milk. It breaks down when two caregivers each assume the other one updated it, and it can't warn you when a fridge bag hits day 4.
A spreadsheet
Free, and you can add any column you like. It's also one more thing to open with a baby on your arm. If you already live in spreadsheets, this might be all you need.
A dedicated stash app such as DairyBar
DairyBar is built just for stored milk. Its App Store listing describes up to 10 storage locations (including a cooler and freeze-dried milk), an estimate of how long your stash will last, alerts before milk expires, a calculator for when you can stop pumping, "freezer bricks", and sharing with partners and family.2 When we checked in October 2026 it was listed for iPhone, iPad, Mac and Apple Vision Pro, free to download with paid subscription or lifetime options.2
If you exclusively pump, keep milk in several places, or want a stop-pumping calculator, a dedicated app like this goes deeper than we do. The trade-off is a second app: your pumping and feeds are logged in one place and your stash in another.
A tracker that already has your pumps and bottles
This is why we added the milk stash to nappi. If you already log pumping sessions and bottles, the stash can fill itself in from those logs instead of being typed twice.
How does the milk stash work in nappi?
The stash lives in Pumping → Stash, and it's per baby.
When you save a pumping session, choose Fridge or Freezer under "Add to stash" and how many bags you split it into. nappi divides the amount across the bags. If you delete that pump later, its unused bags go with it.
Every bag shows a use-by date based on the CDC times above. Thawing a frozen bag moves it to the fridge and restarts the clock at 24 hours. Bags close to their date are marked so they stand out.
When you log a bottle of breast milk, you can pick a bag from the stash. nappi suggests the one to use first, which is the bag with the earliest use-by date. Feed this bag opens the bottle form already filled in.
You can also add milk you stored before using nappi, add a note like "at daycare", move a bag between fridge and freezer, or mark one as thrown away. Identical bags from the same pump show as one row ("150 ml × 4").
Your stash total appears on the Home pumping tile, and Trends → Pumping shows how your stash changed over time. Everyone in your household sees the same stash.
The full storage guide is one tap away in the Stash tab, and the feeding guide covers bottle amounts by age.
What's free and what's Premium?
The stash itself is free: bags, use-by dates, the storage guide, feeding from the stash, notes, and the history in Trends. Knowing what's in your freezer and when it has to be used shouldn't cost anything.
Premium adds two extras. "Lasts about N days" estimates how long the stash will last at your baby's recent bottle intake. A morning reminder at 8 AM lists the milk to use that day.
What nappi doesn't do (yet)
A few gaps, so you know before you start:
- No partial bags. A bag is used or not, so pour-off leftovers aren't tracked.
- Three places only: fridge, freezer, and deep freezer. No cooler or custom locations.
- No stop-pumping calculator.
- The stash isn't on the watch yet. Pumps logged there can be added from the phone.
If one of those matters to you, tell us. The stash exists because a parent asked for it, and the next version will come from the same place.
Frequently Asked Questions
Can I refreeze breast milk that has thawed?
No. The CDC says thawed breast milk should never be refrozen. Use thawed milk within 24 hours if it thawed in the fridge, or within 2 hours once it's at room temperature or warmed.1
Which bag should I use first?
The oldest. The CDC suggests thawing the oldest milk first, which is the bag nappi suggests when you log a bottle.1
Does a deep freezer keep milk longer than a regular freezer?
nappi uses the same CDC freezer times for both: about 6 months is best and up to 12 months is acceptable.1 The deep freezer option is there so you know where each bag is.
Can my partner see and use the stash?
Yes. The stash is shared with everyone in your household, so whoever is doing the bottle sees the same bags and the same suggestion.
If you're building a stash for the first time, start with the bags you already have: add them once, then let each pump fill the stash in as you go. The best baby tracker apps roundup covers the rest of what nappi tracks.
