We recently received a thoughtful message from a subscriber, and I wanted to share it with you, because it highlights something every coffee drinker should know. The message went as follows.
“I have a monthly subscription - 12 oz of Sumatra and 12 oz of Decaf Brazil. I mix them 50/50 and grind about 2 cups each as needed.
However, I noticed the Decaf Brazil seemed short, about 3/4 of a cup.
This happened again with the most recent order.
The Sumatra is fuller, and the Decaf Brazil is not quite full.I’ve measured it out by the cup as I grind it, and it seems about 2–3 cups short.”
A completely reasonable concern, and a great observation. But here’s the science behind it:
Coffee Is Sold by Weight, Not Volume
At Café Kubal, we roast and package our coffee based on weight. When you receive a 12 oz bag, it contains exactly 12 oz of roasted beans, regardless of how much physical space those beans take up.
The thing is: different roast levels have different densities. A dark roast, like our Sumatra, tends to be less dense than a lighter roast like the Decaf Brazil.
The Roast Effect: Why Sumatra Looks Bigger but Weighs Less
Here’s why:
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During roasting, beans lose water and expand.
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Darker roasts (like Sumatra) lose more water and become larger and more brittle.
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Lighter roasts (like Decaf Brazil) retain more density and mass per bean.
So when comparing volume, how full the bag looks, or how much it scoops, light and dark roasts behave differently. A scoop of dark roast may weigh less than the same scoop of light roast.
That’s why it may seem like there’s “less” Decaf Brazil, even though the bag contains the exact same weight.
Going the Extra Cup
After reading this subscriber’s note, we realized this was a good opportunity to explain how roast levels affect the way coffee behaves, especially if you brew by volume instead of weight.
We’ve offered this customer a few options, including a Half Caff blend already prepared, to make their brewing easier. We’ll also be adding this option to our offerings soon!
Final Sip
If you ever have a question about your beans, taste, grind, brew, or packaging, we want to hear it. We’re proud to have subscribers who care so much about the details, and we’ll always take the time to explain and improve.
Thanks again to the customer who reached out. You’re helping us all learn and grow, one cup at a time.