Does Heatwave Affect Coffee Bean Storage?

“How do I store my coffee properly?”

That’s a question we get from many brewers. The simplest way: keep your beans in our original coffee bag, squeeze out as much air as possible before sealing it tight, and store it in a cool room away from direct sunlight or heat—like your living room or pantry.This should keep your coffee tasting great for up to 2 months from the roast date.

(Read more: https://www.sweetblossomcoffee.com/post/guide-to-coffee-degassing-resting-storing)

But what about heat?

We often say “store in a cool, dry place,” but what actually happens when your environment gets too hot? And how hot is too hot?

Let’s break it down.

How Heat Affects Coffee Beans

After roasting, coffee beans release carbon dioxide in a process known as degassing. During this time, oxygen exposure becomes the bean’s worst enemy. Oxidation dulls the flavour, flattens mouthfeel, and mutes acidity and aroma.

When the temperature rises, oxidation speeds up—and so does degassing. This means your beans will lose freshness faster, potentially cutting the shelf life to less than a month. The result? A cup that tastes flat, bland, and muted.

A simple experiment:

We placed two bags of freshly roasted coffee—same roast, same batch—

• One bag sat near a window with heat and sunlight exposure

• The other stayed in a room-temperature space

  
  

After just 2–3 days, the window-side bag expanded more quickly due to rapid CO₂ release. The room-temp bag showed slower expansion over 4–6 days. This is a visible sign that heat accelerates oxidation and degassing, which impacts flavour.

What Can You Do?

Don’t worry—heatwaves aren’t the end of good coffee. A few simple steps can help preserve your beans:

• Store in a cooler area. An air-conditioned room works well. Keep beans away from appliances that emit heat.

• Freeze at peak flavour. Coffee hits its flavour peak after some rest — ours peaks around 21 days post-roast. If you brew and love how it tastes, portion it out and freeze it. Just make sure it's sealed airtight before freezing.

• Already notice a drop in quality? Try tweaking your brew:

Slightly increase the brew temperature

Add 0.5–1g more coffee to your dose

Final Thoughts

A heatwave isn’t scary — but it’s definitely something to consider if you care about flavour. Handle your beans with a little more attention during warmer months, and you’ll still enjoy a delicious brew.

Happy brewing!

*Psst. It's our 10 years Anniversary this year! Stay tune for more surprises during this period. ;)