Plastic or aluminum bottle caps can be unusual collectibles and sentimental reminders of past events. A prized collection of bottle caps can be just as important to one owner as a collection of art is to another. If bottle caps are your thing, you should know how to care for your collection.
Remove beer bottle caps carefully. Unfortunately, some of the most intriguing cap designs come off brands without twist-off tops. If you must use a bottle opener, cover the cap with a soft cloth to protect the facial design. Use the bottle opener over top of the cloth. Gently lift one tine at a time. Work your way around the entire cap in this fashion. Go around the cap 2 or 3 more times until the beer bottle cap releases its hold. Work carefully, and the cap will be in flawless condition.
Wash the bottle cap thoroughly. Use mild dish soap mixed with water and a soft toothbrush. Clean the cap well, paying close attention to tines and grooves that tend to collect debris. Use a fresh toothpick to remove residue from areas the toothbrush missed. Plastic soda bottle caps often have a plastic seal on the cap's interior. Halt bacteria growth by running the toothpick around the edge of the seal or removing it entirely.
Place the cap right side up on a counter with one edge on a butter knife. Allow it to air dry for several hours. Even the smallest amount of moisture can cause mildew to form. It is essential the bottle cap be completely dry.
Use clean and dry, or gloved hands, to move the cap to your display. While casual collectors toss their caps into large jars or shoeboxes, some aficionados use display boxes to showcase their collection. If you don't yet have a display case, line a shoebox with a dry washcloth and spread the caps on top of it without allowing them to touch. Cover the caps with a second washcloth before putting the lid on the box. This is especially important if you collect aluminum beer bottle caps with sharp tines on the edges. Tossing them into a heap can dull the tines or damage the artwork, devaluing the collection you've worked so hard to build.