Yes, your compost pile needs water in order to decompose, but the question is: How much?
Here's the (simple) way I understand it (thanks much to books like Let it Rot! and extensive sites like the University of Illinois' Composting for the Homeowner):
There are organisms that live in your compost pile. These organisms do the work of decomposing all the waste materials you put in your pile, and some of these little guys need water to live. If your compost pile is too dry, they will begin to suffocate and die off, and your compost process will slow down dramatically.
But if your pile is too wet, the water will begin to force the air out of the compost pile and you will have the problem I described last week...rotten egg or other bad smells, and general slowing of the compost.
So how do you know? Well, most things I've read say that your pile should be as wet as a wrung out sponge. The University of Illinois site says to pick up a handful and squeeze it...it should feel damp to the touch and only a few drops of water should squeeze out.
Now, I highly doubt I will be reaching into the tumbler full of rotting garbage and squeezing it to test the water level. I don't gross out too easily, but I just don't see that one happening. I think I'll just eyeball it, and if it looks like it's sopping wet, I'll add some shredded paper and other browns. If it looks like it's not wet at all, I'll get out my watering can and moisten it up.
One more thing. If you're using a tumbler or other enclosed system, make sure it's not airtight. Most are built with some ventilation and this allows both air and rain water to get in. That should be enough moisture for your compost, but keep an eye on it (or give it the squeeze test if you're braver than I am) and you should be all set.
In other news, students at my alma mater have put together a YouTube video about Dan the Can to promote awareness about the new single-stream recycling system in Brunswick, Maine. The students are hoping to get 1000 views by the end of April, and as of today they had 972...you could help push them past their goal!
Thanks to Earthworks for the handy microorganism visual!
Missed anything in this series? It's easy to catch up:
Step 1: Make it a Priority
Step 2: Choose a System
Interlude: Nature Tried to Kill My Composter
Step 3: Collect Organic Material
Step 4: Mix the Materials
Step 5: Moisten the Mixture
Step 6: Wait
Interlude: The Lightbulb Change
Interlude: The Yogurt Change
Interlude: The Sponge Change
Interlude: The Leftover Change
Interlude: The Napkin Change
The Sort-of Sun-Mar 200 Review Part One
The Sort-of Sun-Mar 200 Review Part Two
Sun-Mar 200 Compost Update
Sun-Mar 200: Starting All Over Again
Step 7: Use Your Compost
Step 8: Sun Mar 200 Garden Composter Review