Baking soda and airflow fix musty sofa bed storage

Musty smells in the storage compartment usually come from trapped moisture, and you can treat them without pulling out the mattress.

The quickest thing to try is baking soda. Sprinkle a generous layer all over the floor of the compartment (under the mattress, around the edges), close it up, and leave it for at least six hours or overnight. Then vacuum it up. Baking soda absorbs odors without any harsh chemicals. If that helps but doesn’t fully solve it, repeat once more with a fresh layer.

For moisture control, get a small dehumidifier bag or silica gel pack and toss it in there. Those reusable ones that change color when full are great—just microwave them to reset. Also, crack the compartment open for a few hours every couple of weeks to let air circulate. Mustiness loves stagnation.

If the smell lingers after baking soda and dehumidifying, the foam mattress itself might be holding odor. You said no removal, but if you can lift one corner, you can spray a fabric-safe enzyme odor eliminator (like Nature’s Miracle or similar) onto the underside. Let it dry fully before closing. That usually kills the bacteria causing the smell.

Prevention is easier than treatment: don’t store anything damp in there, and leave the compartment slightly open once a week.

Future you will appreciate not smelling old basement every time you pull out a blanket.