Beer is not a necessary plant feed or watering treatment. Use suitable water for the roots and a labeled fertilizer when the plant needs nutrients.
Watering is not feeding
Use water suited to the plant and check whether the root ball needs it before watering. Beer is not a measured plant fertilizer, and its presence in a household does not make it an appropriate routine treatment for leaves or roots.
Keep the dose known
If an actively growing plant needs feed, choose a labeled product for its growing method and follow the directions. Adding more liquid does not solve poor drainage. Check the mix, container and root condition when a plant is struggling.
Cleaning leaves
Support suitable smooth leaves and wipe dust gently with a cloth dampened with plain water. Delicate or hairy leaves need different handling. Do not apply a leaf-polishing recipe to an entire collection without considering the plants.
Related reading: Beer for Houseplants: A Better Way to Care for Leaves.