“My oak tree is oozing beer!” Homeowners often follow their noses to the base of an oak tree to find a puddle of yeasty smelling liquid. The ooze is usually surrounded by insects, some of whom seem inebriated!
The condition is a common one on large oaks, poplars and maples. It can happen on any tree which has been planted too deeply, burying the lower trunk.
The oozing is called “slime flux” and is caused by a bacterial infection inside the trunk. There are actually two types of slime flux: “alcoholic” and “acidic”. The acidic flux smells like vinegar.
The infection can be in a wound on the trunk surface or it can be deeper inside the trunk. In either case, bacteria ferment the tree’s sap; it seeps out and down to the ground. Sweet-eating insects (wasps, bees, yellow jackets) would obviously be attracted to the damaged area.
There is no treatment for the condition. The best thing to do is to wash off the trunk to discourage bugs. Mix one-eighth cup of chlorine bleach in a gallon of water to make a final rinse. The flow of sap is periodic; it may disappear and not reoccur or you may see it every year.