When you go home tonight, take a look at your makeup brushes.  After a week (or weeks) of use, they’ll likely be caked in pigment, powder, and something else, bacteria.  Recently, the staff at Byrdie tested their makeup brushes for bacteria, and the results will make you want to scrub your brushes immediately.

But even some of the most ardent makeup aficionados struggle with the ins and outs of brush cleaning.  So here are the best tips from the experts.

How often must brushes be cleaned? Bobbi Brown recommends cleaning your face brushes (foundation, blush, concealer, etc.) at least once per week.  Eye brushes can be cleaned every two weeks.  Other brushes like highlighter and bronzer brushes can be done one to two times per month.

Personally, I use a Makeup Eraser cloth to remove grime from my face brushes every other day.  Then, I do a more thorough cleaning on the weekends.

What is the best cleanser for your brushes? Most makeup artists recommend using water and a gentle cleanser.  Do not use dish soap; it’s too concentrated to wash away easily.  I think the best brush cleanser is baby shampoo.  To keep the bristles from drying out, add a bit of olive oil to the mix.

Another option is the beautyblender Blender Cleanser.  If you buy the solid version, you can travel with it.

What is the best technique?  This Good Housekeeping photo tutorial shows you the steps to cleaning a brush properly.  But I have two alterations.

I don’t like to waste water, so I use a shallow dish (like a baking ramekin) instead of a running faucet.  Also,  instead of using my hand to clean the brush, I use a Sigma brush cleaning mat.  The grooves and bristles really clean the gunk off.

How should you dry your brushes? First, ring out the excess water, and blot dry on a towel.  Make sure to reshape the brush head as you dry.  Then, comes the air-drying phase.

Never dry your brushes with the bristles laying on a towel (mildew) or with the brushes standing bristles in the air (the water weakens the glue holding the brush together).  Instead, lay your brushes flat with the brush head hanging off the edge of the counter.  Another option is to use hair ties to secure them to a towel rod upside down.  Or purchase a brush tree to hold the brushes upside down.

How do you clean a makeup sponge?  To clean an applicator sponge, like a beautyblender, the microwave is your best friend.  You soak the sponge in soapy water, and then pop it into the microwave for a bit.  This will not only clean the sponge, but kill any bacteria lurking inside.  Just make sure not to touch the sponge right after you remove it; it will be hot!

How should I store my brushes? Unlike most bloggers, I absolutely do not recommend keeping your makeup brushes on your bathroom counter.  That is unless you want them coated in aerosolized perfume, hairspray, fecal bacteria, etc..  I keep mine in a lidded cup made by Sigma.  This keeps the brushes from getting smushed, which can happen in a makeup bag.

When is it time to throw away your brushes? The FabZilla recommends tossing brushes that no longer hold their shape, shed bristles regularly, won’t come clean, or have developed an odor.

Looking for an easy way out? Several companies are now making sonic brush cleaning devices that will clean makeup brushes for you.  The most well-reviewed is the Brush Pearl which acts like a mini-washing machine for your makeup brushes.

*image c/o Beauty Bean.