NEW HAVEN, Conn. (WTNH) — You look forward to that first cup of coffee in the morning, but are you getting more than coffee? Think about what’s inside your coffee maker.

“When we look at any environment that is warm and moist, it’s really a breeding ground for germs – notably mold and bacteria,” explained Yale immunologist Dr. Ryan Steele.

For a drip coffee maker, taking apart the pieces and cleaning it is pretty simple, but what about a machine that uses a coffee pod, like a Keurig machine? You use a new pod every time, but inside the machine remains that warm, moist environment.

“Simple cleaning with household items like vinegar and bleach, in the right concentration, because too much of those can be very irritating, as well,” Steele said. “You really want to follow the manufacturer’s instructions and routinely clean that.”

We’re not talking about just wiping down the outside, we mean taking the pieces apart to get inside. Your kitchen sponge might not be able to get in there. Your machine may have come with a specialized cleaning tool, or you may have to use a small brush or even a cotton swab to get into all the little crevices.

“You really want to make sure that you’re cleaning all those and removing gaskets because those hidden areas are really ripe for having mold and bacteria grow,” Dr. Steele said.

That sounds gross, but it probably won’t make you sick, unless you fall into one of two categories. One is people with compromised immune systems.

“That could be anybody who is simply on steroids for a rash or for asthma, or who’s on medication long term, like someone who may be a transplant patient,” said Steele. “More broadly in the population, mold allergy is quite common.”

Dr. Steele said you should do a thorough cleaning at least once a week, and don’t leave water in the reservoir overnight. That’s another place mold can grow.