Stale beans? Or is 5 minutes sometimes too long to roast?

Got some new beans from a batch due to expire in mid April. 15 minutes was too long. Even 5 minutes produces dark nibs.

Here are the raw beans (Colombian), and 5 and 15 minute roasts (125c). Both roasts were over, with dark nibs and most of the aromatics gone. I've never had such dark nibs from such a short roast. Grateful for your comments.

Comments
No. 1-7
Limpopolondon
Limpopolondon

Ill try a 100c roast tomorrow

Limpopolondon
Limpopolondon

Here are the raw beans. These were bought from HB Ingredients in UK, knowingly with a short use-by date, for experimenting

DiscoverChoc
DiscoverChoc

Editor

@Limpopolondon -

I have never heard of an expiration date on beans. Who from/Where did you buy them? Can you post photos of an unroasted bean - whole and cut in half? I have never run into the situation where beans essentially burnt at that temperature at that length of time. What happens when you roast at 100C?

Limpopolondon
Limpopolondon

Domestic fan oven preheated to 125c. There’s a best before date on these beans, which are in 10kg bags for small batches

DiscoverChoc
DiscoverChoc

Editor

@Limpopolondon -

What kind of roaster are you using?
Also - why is there an expiration date on the beans?