Flawed Coffee Beans?

I’ve been purchasing whole beans from this same roaster for about 3-4 years, 1-2lbs a month, without issue. Single origin, almost always light roast.

The last bag I bought appeared like any other, except the beans smelled like rancid milk. Again, light roast, no oil/moisture on the beans, no obvious physical flaws.

Bag was ‘typical’ - paper outside, foil lining inside. Small hole to allow gasses to escape. No sign that the bag had been compromised.

The beans were roasted on July 23rd and I believe I began consuming them a few days after. Rancid smell carried over to the coffee. At first I thought the cream I was using expired, but then noticed the smell in the actual beans.

This week I bought another bag. Same toaster, different origin. Same exact flaw. It’s really offputting-hard to actually drink.

Any idea what may be going on?

That’s really odd. My guess would be that the beans were compromised by packaging at some point along the way. It might have been that they were held in wet/soaked burlap bags at some point, and that leeched into the green beans. Even with roasting, that might not be all “cooked” out. That’s a total crap-shoot theory, though.

Never heard of this. I like Brandon’s theory about moisture damage. I’d reach out to the roaster.

Have you had a monsoon coffee? If so same type of smell?

Did you smell the inside of the empty bag and does it have the same smell?

Only things that make sense are compromised green beans or transfer from the bag. The roasting process shouldn’t make a non-rancid bean rancid. If the green beans were bad I would expect the roaster to reject the beans but they may not notice a bag problem. It’s always possible that they knew they were putting out a bad product but did so to avoid the financial hit which would be because the problem was due to their storage and not up the supply chain.

Blame Michel Rolland.

That was my thinking as well- that it was unlikely to be introduced during the roasting process. Would have needed to be introduced before that.

Brian I had the same concerns you did… I’d be surprised if they didn’t notice this, which implies they chose to put out a bad product. Which seems unusual for them as the last 3-4 years the quality and consistency have been fine.

must be moldy bad beans. Roasting won’t do that.

Not fully fermented initially?

Ask the roaster.