If you’ve gone to the effort of expressing your precious milk, it makes sense to ensure every drop is stored safely — and smartly. Whether you’re preparing for a breast milk freeze-drying service like The Milk Fairy, or simply trying to maximise your freezer space, learning how to create “milk bricks” and pack strategically can make a big difference.

In this blog, we’ll guide you through turning your liquid gold into tidy, stackable bricks, and share helpful tips for prepping your milk to get the most out of your shipping kit.

What Are Breast Milk Bricks?

“Milk bricks” are breast milk storage bags that have been frozen flat. Rather than placing your freshly expressed milk upright in the freezer (which leads to bulky, awkward shapes), freezing bags flat helps create thin, stackable slabs — much like bricks.

Why it matters:

When it’s time to pack and send off your milk (especially in bulk), flat-frozen bags fit neatly in your shipping kit. It’s a space-saver, allows for more milk per shipment, and helps keep everything frozen during transit.

How to Freeze Your Milk into Bricks

Here’s how to do it the smart way:

1. Use quality storage bags
   Choose strong, leak-resistant breast milk storage bags with accurate measurement markings. Brands like Lansinoh, Medela, or Pigeon work well — or use the ones provided by The Milk Fairy, if you're using our service.

2. Lay bags flat when freezing
   After sealing your bag (and squeezing out any excess air), lay it flat on a baking tray or inside a freezer-safe container lid. Avoid overfilling — we recommend freezing no more than 180ml per bag to ensure consistent shape and quicker freezing.

3. Label everything clearly
   Use a waterproof marker to note the date, volume, and any other details you need. Write on the designated label area — not directly on the milk-filled section — to avoid smudging when the bags thaw.

4. Stack after fully frozen
   Once your bags are frozen solid, you can remove them from the tray and stack them like playing cards — upright in a container or in large zip-lock bags. This not only saves space but makes packing your shipping kit a breeze.

Other Smart Pumping & Packing Tips

Freezing milk into bricks is a great start, but here are a few more tips to help you get the most from your shipping kit and overall milk storage routine.

1. Follow FIFO: First In, First Out

Always send or use the oldest milk first. This keeps your milk stash rotated and ensures nothing goes to waste.

2. Keep volumes consistent

Try to freeze the same volume in each bag (e.g. 150–180ml). It helps with even stacking, consistent freeze-drying, and makes life easier when logging your supply.

3. Double-bag for peace of mind (optional)

If you’re worried about leaks during shipping, place your frozen bags inside a larger freezer bag or zip-lock before packing them into your shipping kit. While rare, leaks can happen — and it’s better to be safe than sorry.

4. Freeze completely before packing

Make sure your milk is frozen solid before placing it into your shipping kit. Avoid taking it out of the freezer too early, and pack it just before collection or drop-off to preserve the cold chain.

5. Pack tight

Line the bottom of your shipping box with flat milk bricks, fill in any gaps with smaller bags or padding, and place the ice packs where advised. A snug fit means better insulation and safer transit.

Why It All Matters

Breast milk is more than just nutrition — it’s immunity, comfort, connection, and love. When you take the time to express and prepare it, you’re preserving something incredibly valuable.

And if you’re freeze-drying your milk with us at The Milk Fairy, you’re future-proofing that magic for years to come — making travel, weaning, or going back to work just that little bit easier.

Freezing your milk flat may seem like a small detail, but it plays a big role in making the entire process smoother and more efficient. Plus, it feels very satisfying to stack those little bricks, trust us.

Bonus: Your Shipping Kit Checklist

Before you send off your milk, here’s what you’ll want to include:

✅ Flat-frozen milk bricks (as many as comfortably fit)
✅ Completed intake form (if supplied)
✅ Solid-frozen ice packs
✅ Any specific instructions or notes you want us to know
✅ And a little love to yourself — you’re doing an amazing job 💛

Stacking your breast milk like bricks isn’t just a freezer hack — it’s a symbol of how much thought, effort and love you’re putting into your journey as a mother.

At The Milk Fairy, we honour your milk, your story, and your motherhood. From first drop to final shipment, we’re here to make this process easy, empowering and just a bit magical.

So, stack smart, pack with purpose, and know you’re doing something truly incredible.