Grab a bowl and combine one part lemon juice with one part tartar sauce. Mix the ingredients together to create a paste.
Apply the lemon juice and tartar sauce paste to the beer stain with a dry cloth.
Wait 10 minutes, then perform a second application to the leather couch.
Apply Castile soap to a damp cloth. Use the cloth to remove the paste from the couch. This olive oil-based soap helps remove food and drink stains, as well as food and drink odors.
Dry the stain and buff the leather couch with a dry cloth.