So, as some have suggested, sprinkling some soil into your composter once in awhile certainly can't hurt. Got about 20 wheelbarrow loads of the stuff this year. Have a garbage can full in the garage and a bucket in the basement. All the houseplants love the stuff too. Screening them out is not a favourite chore and I must say it's been easier this year.
Any clumps just break up and fall through screen quite easily now.
Am going to built a tripod or some such arrangement to suspend the screen from before next season. Will just wheel the wheelbarrow up under it, load the screen, shake with one hand and off I go. Am still loading the thing up with kitchen wastes and prunings from the indoor plants although it doesn't amount to much. Thankfully the snow quickly covers it as it doesn't look all that sightly across the vista of pure white yard and snow clumps on the cedars. Mind you the squirrels won't go to sleep, they keep digging it up and taking the choice tidbits.