Tumbler contents are too wet.
My compost tumbler has turned very wet.
What do I add to absorb the liquid?
I had a Similar Problem
I have been testing a compost tumbler on my deck for the summer and ended up with a similar problem. My compost was almost soupy.
The first thing I did was to check the drain and I opened it and left it open. This didn't dry things out enough so I tried shredded paper which did work to some extent but it seemed like I'd need to add an awful lot of paper to solve the problem.
Then I read the directions that come with the Jora composter, a tumbler made in Sweden. They recommend using wood pellets, the kind you use in a wood pellet stove.
I bought some at our hardware store - about $5 for 40 pounds - and wow they really work.
These wood pellets are made from compressed wood. The lignin in the wood is what holds them together. They are dried down to a 5% moisture content. This is perfect for wet compost because the pellets can absorb a lot of water. As it absorbs water the pellets break apart and become a nice fine part of the compost.
Hope this will solve your problem. If you can't find wood pellets use a lot of shredded paper.