Why is my compost tumbler not heating up?

  • By: composthq
  • Date: April 2, 2022
  • Time to read: 5 min.

When you are learning to make your own compost you’re full of energy and facts and it is easy to get impatient.

You want to know that the process is running perfectly and it can be a big disappointment when you notice that your tumbler is rather cold to the touch.

Naturally, you might feel a touch of panic and ask yourself, “Why is my compost tumbler not heating up?”

The most commons reasons are an improper ratio of greens to browns, compost that is too wet or dry, or even sneaky novice-traps like whole leaves or old compost present in your mix.

Today we’re going to give you a crash-course in the most common impediments of composting. We’ll touch on these issues we’ve mentioned in brief and then expand these pitfalls for you.

This way you’ll be checking items on your mental checklist and by the end of the article you’ll likely have your solution.

Without further ado, here are the most common culprits to look for when that compost-alchemy simply isn’t occurring.


You might be using too many greens

One of the most common reasons that a compost heap is not heating up is that there are simply too much greens. You want to go with 2 parts brown and 1 part green.

The browns, of course, are your carbon, while the greens are your nitrogen. Sometimes when we are preparing the heap we can make a mistake, such as adding coffee as a brown.

This is an easy and common one, as coffee’s color might make you forget for a moment that it’s rich in nitrogen.

In order to help you to do a quick mental assessment of your current compost heap here is a quick list of brown examples for carbon:

While here are some reminder examples of common greens, for nitrogen:

  • Coffee
  • Fruit and vegetable scraps
  • Tea bags
  • Animal Manure
  • Grass and weed clippings

Most commonly too many greens is the problem so keep in mind, if you add a grocery plastic bag full of a green such grass clippings. you want to add 2 bags pine needles or shredded up paper.

That 2 to 1 balance is the key.

Smelly compost can be a sign of too many browns

If the compost heap is started to smell pretty bad and it’s looking a little goopy then you might need to beef up on browns to enforce that important 2 to 1 ratio.

While coffee can give you nitrogen, at this point things like wood chips, straw, and twigs are the best thing that you can add.

This will provide a bit of spacing along with that dose of nitrogen and things should to heat up within the next 24 to 36 hours.

Are you using fresh or whole leaves?

While leaves are one of the most commonly used brown sources in your compost they need to be shredded up properly in order to work their magic.

Whole, fresh leaves are quite durable, taking up to 6 months to properly decompose, and don’t even get us started on leaves like Oak which can take up to 2 years to decay.

You can still use your leaves in your compost, of course, but you’ll want to grab your lawnmower out of the shed or your garage and give those leaves a good blade-thrashing to tear them up.

This way they will decay at the right rate and if you’ve for your greens and browns balanced out enough then your compost will start doing its thing.

How wet is your compost?

If your compost is too wet and packed in your tumbler too tightly, the lack of air is going to interfere with your composting, One the flip side, if your compost is too dry then you aren’t going to get any magic either.

The solution for both problems is fairly simple and straightforward.

If the compost is too wet, we’ll dry it out a little. If it’s too dry, we’re going to add some water.

To dry your compost you can get a bunch of old newspapers and create a large, square area where the compost may be dumped and spread out on newspapers to dry a little.

The balance that we are trying to achieve is a solid mass that is rather like a sponge that you’ve just wrung out. Think of the ideal compost as damp, not wet, and you’re on the right track.

If your heap it too dry, adding a bit of water can help, and if you are worried that you might add too much then you can simply add a little water and some fresh manure.

Also, if the process has moved a little but has been far from ideal, you can always ‘cheat’ with some commercial accelerator but doing without it excellent practice.

It also saves you a good chunk of change in the long run, just something to consider.

Do you have old compost mixed in there?

Mixing in old compost with new compost that you are making is not a good idea.

The biggest problem is that a part of your mixture has already gone through the chemical process of heating and maturing and what happens now, is that it can get in the way of the fresher materials doing the same.

For best results and especially if you are just getting started with making your own compost in the tumbler, we recommend that you focus on learning all of your greens and brown and in the beginning, that you measure carefully and make a few batches first.

With practice you’ll eventually just KNOW the right amounts, but for now you’ll want to get a feel for it.

How to know when your compost is done to perfection

When the process has been done properly, it will have a bit of a damp-forest smell to it and crumble up nicely when you pick it up. Much like a deep brown potting soil.

The temperature is, of course, going to be your biggest indicator that you are on the right track. If the tumbler isn’t warm after 24 – 36 hours then you need to check your heap.

These tips should get you where you need to be, just practice your measurements and above all, be patient. In a short amount of time whipping up a good compost is going to be second nature to you.

We promise!

Related Posts

Previous Post

How long does it take for orange peels to decompose?

Next Post

Materials that can compost within one month (how to make a fast compost)

error: Content is protected !!