Thanks for your informative reply - I have learned more from you already!. I am mainly adding kitchen scraps to the bucket, - fruit and vegetable scraps, peels, apple cores, things like that - but I am also adding old leaves, stems and parts of old plants from the garden, as well as what's left over from microgreens I have harvested (a mixture of coco coir and roots). But if all of this quickly becomes unappetizing to critters I assume it own't be an issue!

Based on what you've said it sounds like it will work if I just mix the contents of the bucket with soil in a container and let it break down in there until it is uniformly dark? Actually, it sounds like I don't even need a bucket but could just continuously add stuff to a container with soil and wait for it to break down - which would be the easiest way of all.

It may be the easiest way but not the fastest. If left alone, anything vegetative will decompose with time, even in a bucket or container. But you will speed things up by allowing plenty of oxygen to get to the mix. That is best done by just creating a pile, either with no sides or open sides (like chicken wire). You can approximate that if your bucket or container has plenty of air holes - most do not - but just piling the material up and giving it a toss with a garden fork now and again is gonna get you there faster and just as easily.

That's a good point that composting time will also be minimized by proper oxygenation.

Yes, mixing the contents of the bucket with some soil and letting it compost will work fine. Do keep it moist, and turn it regularly. Just dumping it from one container into another every week or two will do the latter.

You don't need to add soil to make compost. And I think you'd do better in something bigger than a bucket. You risk ending up with a pot of smelly slime. You're actually making life harder than it need be by trying to compost in an enclosed container in a small volume. If you start a pile as suggested above compost will happen.

Adding a little soil is an effective way to innoculate the mix with the bacteria you need. A container will work fine, but in order to avoid smelly slime, keep the mix moist but NOT soggy, and oxygenate properly. Smelly slime is what you get when you have an overly wet mix that is anaerobic. An overly wet mix will actually prevent proper aeration.

If I read correctly, the bucket was what was being used to just collect the materials.

Every winter and spring I make a few yards of leaf compost. I grind the leaves up, put them in piles, and keep them moist. After a month or two composting is well along, but not quite complete. I transfer the moist mix to plastic 40-gallon trash cans, where the composting continues more gradually. No slime. No smell.