One of the more frustrating tasks a homeowner confronts is cleaning the grout between the tiles in the bathroom or kitchen. This process usually involves caustic cleaners, frantic scrubbing with an old toothbrush, and a lot of lost time.

One way to keep your grout looking nice and minimize the effort required to clean it is the oft-overlooked process of resealing the grout. Doing so will help keep the grout from absorbing moisture and developing stains, giving it a nicer appearance and making it easier to clean.

How often you reseal the grout depends on how much exposure the grout has to moisture. Jill Lawrence-O'Hara, writing for the home improvement professional Bob Vila, says resealing once a year is good for areas that don't get too much moisture. For tiles in the bathroom, especially in the shower, you may want to reseal them more often; once every six months will typically be adequate.

Test the grout to see if the previously applied sealer is still working well. AmeriClean, a cleaning and restoration company based in Merrillville, Ind., says you can put a few drops of water on the grout to see whether it beads and stays on the surface. If it is absorbed instead, the sealant needs to be replaced.

Before resealing your grout, you'll need to make sure it is clean and in good condition. Lawrence-O'Hara says you'll want to repair any cracked or crumbling grout and scrub dirty areas with soapy water or a vinegar solution. Failing to do this step means any damage or grime will be sealed in.

A toothbrush or other stiff brush is ideal for cleaning grout lines, and a tile cleaner will work well to clean up especially grimy areas. Rinse the cleaner away and allow the tile to dry completely before you start the resealing process.

There are a variety of grout sealers available, so you'll want to choose one that works well for the tile's location. Look for one that is rated for the tile material, such as marble or ceramic. Penetrating seals will fill the porous areas of the grout to help repel moisture, while other sealers will form a membrane to keep the grout from absorbing water.

You can also choose how the sealer will be applied. Lee Wallender, writing for the home design site The Spruce, says some will have an applicator brush which allows you to put the sealer directly on the grout lines. A faster option is an aerosol spray which can be applied to a wider area.

Another option is to use a sponge to apply sealer. Lawrence-O'Hara says this method is particularly useful on thin grout lines, since it allows you to easily spread sealer over a wider area.

Sprays allow you to finish the job faster, but may not be as effective as sealers that use an applicator. The latter option is time-consuming, but does a good job of creating a strong seal over your grout.

Use a dry cloth to wipe off any excess sealer that made its way outside the grout lines. If the sealer is left on the tile, it can leave a filmy residue.

Follow the instructions on the sealer. Audrey Ference, writing for the National Association of Realtors, says you may be able to add a second coat after just 15 minutes. Allow the sealer to cure before exposing it to moisture; this may take up to 48 hours.

Retest the sealer to see if it is working properly. You should again put a few drops of water on the sealer to see if it beads up.

Most grout lines will benefit from resealing, but some won't need this maintenance. Wallender says you can skip this process for the parts of a kitchen backsplash that aren't frequently exposed to moisture or food spatters. You also won't need to reseal grout on decorative tiles.