Hotbin Composter: your top 5 questions answered

Since we started using the Hotbin Composter, we’ve had quite a few of you asking questions about how it works and what to expect from it, and, even some of you asking for help with getting yours going. So we thought it might be a nice time to answer some of those questions.

I put a shout out on twitter and Instagram this week and asked you to send us your questions and I then collated these into the top 5 questions we got so that we can answer them for you here. Not surprisingly, the questions were all things we’d seen before, probably because these are the biggest worries people have when they switch over to this system, so here we go, in order of how many times we were asked the question… your top 5. I bets you can totally guess what the number one question was…

Does it really actually get that hot?

Yup, healthy scepticism. Cause let’s be honest, we are so used to companies spinning us that we can’t help but ask, is this for real? I suppose this is why it’s so good to be able to look online for other folks in similar situations to yourself and ask them how they have found things. You know, get a proper honest opinion. I know that’s what I do.

The company advertise that the bin runs at between 40 and 60c, and because of this, it is safe to compost kitchen waste (including raw meat) and even perennial weeds. It is this running hot thing that makes it work so fast as well. The claim that it makes usable compost in 3 months.

So what is our experience? Actually, yup it really does get that hot. You’ll hear me say this a lot, but it’s all about what you add to it. Add the right stuff, in the right proportions and yup, it goes.

I’ve seen me get a full-on facial steam bath when I open the lid. Because of this, you do really notice how quickly it chomps through things when it’s running that hot. You fill the bin and a few days later, the amount has noticeably dropped and you can add more.

Does it stay that hot all the time?

An obvious follow on question. So we’ve established that it gets as hot as advertised but is this a one-off thing or does it actually stay like that? This is actually something that I have been asked ever since I first posted about buying this bin and as you guys may already know, something I struggled with.

The first year with the bin was a very steep learning curve for me, and although I discovered I could get the bin hot, I struggled to keep it hot. As I mentioned before, this is all about the amount of waste you add and the type.

It’s the green waste, so the kitchen scraps and garden waste that get the heat, because they are easy to break down and so quick and they tend to be higher in nitrogen. Because of the speed that they break down, this is what generates the heat. So if you can keep the bin topped up with the right mix of “ingredients” then you do see that heat stay.

For us though, we struggle to maintain this. We just, as a household, we just don’t have that amount of waste to add, either form the kitchen or the garden. So during spring and summer when there is a lot of grass going in, yup the heat rockets and easily hits the 60C. But we’ve accepted that the rest of the year, the bin is basically sitting composting like any other compost bin, usually at about 10 – 20C.

Am I adding the right amounts of things?

Ok this was the one that took me the longest to get to grips with. There is a lot of confusing info out there so let me simplify it.

Whatever you add as kitchen and garden waste, you need to add half as much again as paper. The paper helps deal with all the liquid from the waste and stops it becoming a wet stodgy mess. Too wet and you won’t see that heat AND it smells. In the beginning, we were really struggling to get it hot, and it was always so wet. A bit of trial and error and we realised we weren’t adding enough paper. Again though, paper is not an easy thing for us as we are a paperless household, so we’ve had to beg borrow and steal newspaper.

You also need to add something that helps maintain airflow, so something which stops it all becoming compacted. They recommend shredded wood chips. Also, you need to give it a good mix every so often to let the air through it. Cause the bacteria need the oxygen.

Why can’t I get mine hot?

OK here is the million-dollar question.

Even with all the right ingredients and the right amounts, and all the love in the world… the bin won’t start getting properly hot until it has a certain level of “food” in its belly. Basically, it needs to be full to above the hatch. So if you are starting off from empty, like I often do, it’s going to take a few weeks to get going. So patience young padawan!

Why is my compost so wet?

Ok, this was my number one question, for me personally. I had 4 loads come out of the bin while I was trying to get on top of things and they were all sodden.

Before I could properly use them, I had to lay it out on a tarp and let it dry in the sun.

Again, this fell into my realisation about the paper. I just wasn’t adding enough paper to my mix to make sure all the liquid from the green waste was being taken care of. Once I was adding the correct amounts of paper I saw a marked improvement and the last lot I emptied (the other week for the raised bed) was remarkably dryer.

Now I don’t saw perfect and dry, I say dryer because I suspect having your bin running hot all the time would help with this too. My last lot had sat at normal pile temperatures over winter, so there was no steam, and therefore no evaporation of any of the moisture.

So there you go… what I’ve learned from my adventures with the Hotbin Composter. I hope this is helpful for you guys on a similar adventure.