Mildew is a type of mould that flourishes in damp, warm conditions. An opportunistic fungus, mildew thrives on a variety of surfaces and can be found growing on everything from wood and plastic to silk and leather. In the early stages of mildew infestation, the growth is not visible but can be detected by a dank, musty odour. In addition to causing leather and other materials to smell, if left untreated, mildew will multiply and can eventually ruin even the finest of furnishings. Fortunately, there are some simple home remedies that can help to remove the smell of mildew from leather while effectively killing the underlying fungus.
Remove as much visible mildew from the couch as possible by buffing any affected areas with a clean, dry cloth or small, nylon-bristled brush, knocking loose mildew to the floor. Vacuum up the loose mildew pieces and throw away or empty the vacuum bag.
Combine 1 cup of either isopropyl alcohol or distilled white vinegar and 1 cup of water. Mix well, until the two are thoroughly combined.
Pour the solution into a plastic spray bottle.
Test the solution in an inconspicuous spot to be sure it will not cause streaking or staining on the leather prior to applying the mixture to the sofa. Spray the test area lightly and then wipe the solution away with a soft cloth. Wait for the treated area to dry completely and then evaluate the area. If no discolouration or damage is apparent, continue.
Spray the sofa with the dilute alcohol or vinegar solution. Be sure to cover all portions of the couch, paying particular attention to the corners as mildew thrives in dark places.
Wait five minutes and then wipe any residual solution away with a dry cloth. Any alcohol or vinegar aroma will dissipate over time. Wait 48 hours to assess the effectiveness of the treatment and repeat if necessary.
Treat persistent odours by placing a shallow dish filled with coffee grounds in the centre of the couch cushions and then covering the sofa with sheets of plastic. Tuck the edges of the plastic beneath the sofa, sealing the coffee inside. Leave the couch covered for three to five days and then remove the plastic. Dump the coffee into the trash and run a vacuum over the leather to remove any loose grounds.