I love my tumblers. They work really well for fast composting once you figure out the art side of it. Getting the C:N (brown:green) balance right is a bit of art. You can speed up the learning or figure-it-out process by getting to know the C:N ratios of what you're using as feedstocks. How full is optimal may depend upon the specific tumbler you have, but in my experience with two different brands, both horizontal drum types, they work best at about half-full. I use two 90-gallon tumblers. Using aged shredded wood mulch as browns and kitchen produce trim + UCG as greens, it takes me about 4 weeks to half fill one. During the fill I do not tumble, but layer. I've found it seems to work best if I start with a couple of inches of wood stuff, then add the greens as mini-piles 2-4" thick, covering each with more wood mulch for every addition. I do NOT mix during this build-it-up period, by do water starting after about two weeks (the mulch is really dry and soaks up a lot of water. How much is a learned thing. After it's half full I start the daily tumbling, six revolutions. It takes about 4 weeks to get to mature compost. I use an old fashioned 4-tine cultivator (think pitchfork with bent times) to pull the stuff from the ends towards the center after each tumbling session - it helps with the heat-up in what would be a shallow pile.

I can offer you some amount of encouragement, but I havenÂt composted with only grounds & paper, not yet at least. Yes, it is very easy to over water; I would suggest resisting the urge to use a garden hose full blast in the tumbler. Here is what I might do: load the tumbler ¼ with shredded paper, add a couple of bags of coffee & give it a spin to mix. At this point take a handful of material and ask does it feel damp? If squeezed does it drip more than a few drops of water? Use a watering can if needed, then add the rest of materials while still turning and checking, Remember that is easy to add more water tomorrow than to contend with a too wet load. Next is the small question of diversity. Might I suggest a little seaweed from the Presidio, crab shells from FishermanÂs Wharf & a bag of leaves from Golden Gate, plus the usual kitchen scraps. My money is on that you will have heat in the next 24 hrs! I prefer to think positive whilst starting the tumbler.

jeannie - if you checked the link above [here] you'd see it takes me about a week to collect enough mixed food waste to fill the digester with about 2 yards of material, then after 10-14 days in the tumbler, the temp has fallen back to near ambient, and the material is ready to be windrowed for maturing - as bpgreen points out, a 5gal pail including soil isn't "composting", to me it would simply be waste collection, and what I usually add to my bins daily is at least 4-6 times a 5gal pail - by the time one bin is full, about 7-10 days, and turned out to the next bin, there is very little recognizeable material in it ... by the time that bin is turned in another week there is nothing recognizeable - shows a pile built over a week that's being turned - note the top is obvious veg scrap and paper, lower down it's much less recognizeable, after only a few days "finished" compost can be "totally" broken down to stable humus, or it can be far enough past the heating stage that it's ready to be used to amend the garden or feed the worms, but you don't achieve that in a short time with no effort, it requires gathering the right combination of materials, useing a setup & equipment that will allow control of the process, and close attention to aeration and moisture control - I think I did point out above that if you only have small amounts of kitchen scrap and the average yard waste without much variety, a tumbler and hot composting might not be useful "most compost experts" would know full well that "finished" compost using a well controlled hot process will never take more than a month .... maybe you should read some of the professional literature rather than citing pop lit newspaper writers as "expert", and in fact I have written quite a bit about composting, here, and locally ... as a certified Master Composter I do a lot of educating of folks in my area about composting, starting with my compost pages, here and here, as well as live demonstrations .... stop in when ya visit the Island :) folks who make major amounts of compost don't invest in setups like this to produce one 'crop' a year, instead they use equipment that can process multi TONS per day, and my interest is in dealing with the major amounts of organic waste produced by landscapers Bill

I have used the expensive Jora tumbler that Rysanna has, and I can vouch for all her comments. I have also used the 37 gallon plastic one that one you are considering. I got mine for $20 on Craigs List, and it lasted about three years - gradually falling apart. But it was tucked into a corner of my community garden plot so I didn't really care, until it was cracked and no longer being held together. But let me break this down, starting with the advantages / disadvantages of tumblers in general, and the same for each of the models. Compost Tumblers Tumblers have advantages. They keep the decomposing food away from rats and raccoons. (This is a big plus if you live in the city. Dumping scraps in a pile creates Rat Heaven and the consequences will be borne by your neighbors and their pets. ) When used optimally, they speed decomposition. (But the requirements for optimal decomposition may not jive with schedule with which you produce scraps. More on that later.) They look tidy compared with your average compost pile. If your yard is in view of the neighbors, this may be important. They also have disadvantages. While expensive models give you every advantage above, cheaper ones don't. See the discussion on models below. On average, they don't hold that much. Of course, they come in different sizes. But you need a volume of about a square meter to even get the composting process going. Most of the inexpensive models are much smaller than that - and remember if it has two bins, each bin is it's own volume of compost. This means that only the very large models have the mass to heat up. Of course, the next question is do you produce enough material to fill a large compost tumbler - and how quickly? Let's examine that last point in more detail. There are two different reasons for composting. You want to process your daily food and garden scraps into something useful. In other words, the process needs to match the input you have on hand - that is the measure of success. You want to produce your own compost for your gardening needs so you don't have to buy it at the garden center. Here, success is defined by the output - having the compost ready in sufficient quantity when you need it. You sound like you fall in to the first category. In other words, you don't want to have to be scrambling around to procure extra greens and browns so you can fill your garden with X amount of compost in the spring. You want your composting process to match the way you produce raw material for the bin. You want to be an ecologically responsible consumer, and the compost you get at the end of the process is just a nice bonus. Here is what you need to understand with that approach - that is not the optimal way to produce compost. So, claims of garden-ready compost in a couple of months will not be your experience. The optimal way to produce compost is to add all the greens and browns at once, and they should amount to at least a meter square in volume. (More is better.) Then lock them away and tumble occasionally until it is done. Empty the bin, and then repeat. On that schedule, you will get 3 or four bins of compost per year. (Remember, if it is double sided, each side counts as a bin.) If your bin is smaller than one meter square, then it will take longer - twice as long or more. And here is the big "but" - but that is not the way you produce scraps in your daily life. You produce a little at a time, and then you will add it to the bin. At that rate, maybe it takes you a month to fill up your one square meter bin. You close the bin, and at that point the composting clock begins. If you have a double-sided tumbler, then you start filling the other side. And here we come to the composting tumbler workflow problem - if it takes you a month to fill a bin, and then it takes two to three months to produce compost, you will have two months when the composting bin is unavailable for scraps because it is "cooking". The process is not successful because, remember, your main goal is to deal with your constant flow of scraps. In order to deal with your workflow, you would need four bins - one collecting that month's scraps and three cooking compost. What often happens is that people keep throwing their scraps into the composting bin without ever closing the door and letting it process. And then they wonder why the compost is never "done". So, what have we learned? You need to know how much raw material you produce a month and buy 4x that capacity in tumbler volume. That might be four separate tumblers or two big dual-bin tumblers. Now let's see how two different products stack up to the job. Small 37 Gallon Dual-Bin Plastic Tumbler (less than $100 new) Advantages: It's affordable It's small so it's easy to fill quickly It's not that hard to put together Disadvantages: It's too small to get very hot - if it was a single bin it might be almost big enough. But divided in two it will take three to four months in the summer to cook a batch of compost. It is useless in the cold months. Composting will be suspended until the temp go over 50 degrees. If exposed to the elements, it will stay intact for about two to three years. Then you will see cracks, leaks, doors may no longer close properly, nuts and bolts will rust and weaken. Five years is the most you can expect to get out of this. You can extend it's life by emptying it in the fall and bringing it in to the garage until spring, if you live in a cold climate. Jora Composter Tumbler JK270 (less than $500) Advantages All metal exterior with a foam plastic insulated interior. Stand, turning mechanism, and latches are all higher quality. Each bin is about the size of the entire 37 gallon plastic tumbler. Should last for ten years easily - more if given some protection from the elements. Can compost into the fall and early spring - though it will slow down when temps go to freezing. Disadvantages Expensive! How many bags of compost could you buy at the garden center for the price of this thing? Makes you really question why you are doing this at all. About twice the size of the black plastic tumbler. A challenge to assemble - give yourself a whole afternoon and have a helper. I should mention that the JK270 model is just barely big enough to get compost cooking. To really do the job you would want the next highest model, the 106 gallon JK400 that costs about $900. That will do hot composting all year round no problem. But, the question then becomes do you produce enough scraps to fill the thing? But maybe instead of two JK270s you could get by with one JK400? In that sense - it's a bargain? Conclusion If you live in the city or a suburb with strict home owner's restrictions, a compost tumbler may the only viable option. However, if you want tumbler composting to meet your scrap output and produce timely compost (so you can empty the bin and start over again) you either need a whole lot of cheap tumblers, or one or two big expensive ones. Otherwise, they simply won't be successful for you. There is one more alternative - one that works inside the house or basement and won't require home owner association approval - worm bins. They are easy to keep and maintain and respond well to gradual adding food scraps. They are messy to extract the compost, though. Just something else to consider.