This is a question we get from time to time, especially with our freshly roasted beans like our popular Mocha blend. Here’s exactly what’s happening and why it’s actually a good sign.
The Magic of Fresh Roasting & DegassingWhen we roast coffee beans, a lot of heat and chemistry takes place inside each bean. One of the by-products is carbon dioxide (CO₂) — quite a lot of it. Even after the roasting process finishes, the beans continue to release this gas slowly over the first few days (and sometimes up to a couple of weeks). This natural process is called degassing.
If we sealed the beans in a completely airtight bag right after roasting, the build-up of CO₂ would cause the bag to inflate dramatically — and in extreme cases, it could even burst. That’s why every Bay Beans bag features a small one-way degassing valve (you’ll find it at the top rear of the bag).
This clever little valve does two important jobs:
- It lets the CO₂ escape safely as the beans degas.
- It keeps oxygen and outside air from getting in, which helps preserve the freshness, aroma, and flavour of your coffee.
Why Do the Bags Look Different?Not all bags behave exactly the same, and that’s perfectly normal. Here’s why you might see variation in the same box:
- Valve sensitivity — Each valve has a very high tolerance, but they can open and close at slightly different rates. Some bags release gas a little faster than others.
- Position in the box — Bags at the bottom often have the gentle weight of the bags above them pressing down, which can cause them to look more compressed or “vacuum-packed.” Bags near the top have less pressure on them, so they can appear puffier.
- Journey across Australia — Temperature changes, altitude shifts, and the long trip (especially to places like Western Australia) can also influence how much the bags expand or contract during transit.
You can test it yourself: gently squeeze a puffy bag and you’ll feel (and often hear) the excess air safely release through the valve — without letting any harmful oxygen back in.
Is It Still Fresh and Good to Use? Absolutely yes. In fact, this variation is often a sign that your coffee was roasted fresh to order and is still in its ideal early degassing stage. The beans inside remain protected and at peak quality.
Quick tip: If you prefer, you can give the puffier bags a gentle squeeze before storing or opening them to help the process along. Otherwise, just store them in a cool, dry place and enjoy them as normal. Your Mocha (or whichever blend you ordered) will brew up rich, smooth, and delicious.
At Bay Beans, we roast in small batches daily and ship Australia-wide so you get the freshest possible coffee — and these clever valves are a small but vital part of making sure it arrives in great condition.
Have you noticed this with your orders before? Or do you have any other questions about how we roast, package, or deliver our coffee? Drop a comment below or reach out — we love hearing from our customers.
Ready for your next fresh delivery? Browse our range of single origins, blends, and decaf at baybeans.com.au
Happy brewing! ☕