First up on The Kitchen cleaning list is the drip coffee maker. We use it daily and it always has hot water running through it—so no big deal if you don't clean it, right? The truth is, studies show that over half of households have yeast and mold growing inside the water reservoirs of their coffee makers, to say nothing of mineral deposit buildup. So, yes, you should clean it. But when, and how?

The good news is that giving the coffee maker a good cleaning monthly should keep it fresh—and it's pretty simple to do, because the coffee maker can clean itself. A brew cycle of lemon juice and water will get rid of possible contaminants. Add 1 cup lemon juice and 1 cup water to the reservoir and let it brew (no need to juice fresh lemons; use bottled 100 percent lemon juice concentrate). The acid breaks down mineral deposits, kills mold and also helps clean the carafe. Once the hot solution comes through into the carafe, scrub it with a bottle brush or cleaning toothbrush, then run a second cycle of just water to rinse out the lemon solution. Plain white vinegar in place of the lemon juice also works well.

Next item on our list is the old-fashioned crank can opener. When should you clean it? After every use! Food particles and liquids from canned products can build up on the gears, providing the perfect environment for bacteria to multiply and for the blade to rust. Cleaning this one is easy, too. If you're guilty of not cleaning yours in a while, scrub the gears and blade with hot soapy water using a toothbrush or bottle brush, getting into all those hard-to-reach areas. Thoroughly dry the can opener to prevent rusting.

You boil water in the kettle every day for a delicious cup of tea. You even wipe down the exterior from time to time. It's easy to assume that the inside of the kettle is clean, since you're just boiling water, right. Wrong! So, when should you clean it? Monthly again, to get rid of mineral deposits left behind by hard water—and to get rid of those unsightly food splatters from your stove.

You'll need something abrasive, like a bottle brush or the rough side of a kitchen sponge, to scrub away the minerals and oils. Baking soda makes a great gentle, non-toxic scrub; add it to a sponge dampened with a bit of vinegar. The two together will cause a bubbling reaction that helps loosen up grease and grime.

That brings us to the kitchen sponge itself! The internet is abuzz with articles about the nasty germs that are harbored inside your kitchen sponge, and there is truth to them. Bacteria can build up deep inside, especially if you leave it soaking wet. To keep those cooties at bay, wring it out thoroughly after every use. Microwave sponges on high for 1 minute once a day to kill some of the bacteria lurking inside. You can also put them in the dishwasher set to the hot dry cycle.

Sponges also raise the question: How long should you keep it? Only two weeks! If you're concerned about the waste produced from throwing away sponges so frequently, switch from traditional synthetic ones to natural biodegradable ones, made from materials that break down.