My coffee beans look oily. Is that OK?

by Mac
(Brooklyn, NY)

Dark roasted coffee beans with an oily surface

QUESTION:

Just opened two bags of whole bean coffee and looking inside bag it was very obvious that the beans are wet or oily. Should I be concerned about the beans turning rancid or moldy?

In one of your answers, you state: It’s the roasting process that changes everything. From the moment coffee beans come out of the roaster, they begin to lose flavor. That’s because the volatile oils in coffee begin to evaporate, and it is in those oils that much of the flavor can be found. ...

Could the moisture I see be these volatile oils and is that a problem, future problem, or no problem?

Mac


ANSWER:

Mac, hi

It seems you have both asked and answered your own question! : )

Yes, coffee beans contain natural oils. These come out to the surface during the roasting process. The darker the roast – up to a point – the more oil you’ll see on the surface of the bean.

And yes, as you say, volatile elements within those oils begin to evaporate as soon as the coffee beans are roasted. This is why, ideally, you want to grind and brew your beans within a few days of roasting.

And what if you don’t see any oils on the surface of your beans? That’s OK… particularly with a light or medium roast. The absence of an oily surface isn’t a bad sign.

As for the oil being a problem… not as far as I know. Potentially, the oil could turn rancid. But hopefully you’ll have used the beans before that would happen!

Best wishes,

Nick

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