With HOTBIN you can compost all year round as the heat produced by the bacteria is contained within the HOTBIN. Therefore, you can also start HOTBIN composting in Winter the same way as any other time of year.
Start by:
- Adding a thin layer of twigs in the base
- Add fresh waste (a mixture of easy and hard to digest waste is best)
- Add in the advised ratios of paper and woodchip (bulking agent) for waste added
- Be patient (waste level needs to be above hatch to create initial heat surge)
- Use HOTBIN hot water bottle if outside temperature is below 15°c
The HOTBIN (200l) and HOTBIN Mini (100l) are continuous hot composters that require waste to be added on a regular basis giving the bacteria a new food source to digest and produce heat as a by product of this process. If you are continuing to add the minimum amount of waste required for your size of HOTBIN you should be able to maintain hot composting temperatures throughout the colder periods.
Do I Have Waste to Compost Through the Winter?
As you may expect there is less garden waste over winter, so potentially less to compost. However, this does not mean that the HOTBIN will stop working over winter or that you need to let it go dormant, just bear in mind that even when/if the bin is running below 40°c it is still composting faster than many other composting systems. If you are continuing to add waste along with paper and woodchip during the colder months the bacteria will still be digesting the waste and creating compost – although you may find it takes long than 30-90 days to produce compost. There are however a few ways to compensate for this drop in the availability of waste and maintain a higher composting temperature.
- Carry on composting food waste, such as fruit and vegetables etc – just avoid cooked food waste if internal temperature is under 40°c
- Ask friends and family for waste – might seem strange but it is something we have done at head office to keep our test bins running and helps others reduce waste going to landfill
- Check our list of will it compost posts to see if there is anything you may not have thought of
- Check out this post on winter composting materials
Using the HOTBIN Hot Water Bottle
If using the hot water bottle when starting your HOTBIN you must create a base layer of waste to above the top of the hatch – approx. 40cm deep.
- Carefully fill your bottle with hot water
- Replace lid tightly and carefully carry the container to your HOTBIN
- Bury the bottle in the top layer of waste, covering with fresh waste
- Leave for 24 hours and do not open during this time
- After 24 hours check lid thermometer is above 15°c
Result: Bacterial process is kick-started, if not repeat process one more time. More information on using the HOTBIN Hot Water Bottle can be found here
Please Note:
- Always wear gloves and handle with care
- The HOTBIN hot water bottle is designed to hold hot water. Please DO NOT substitute bottle with another plastic or glass bottle as this may result in injury
- Do not pour boiling water directly into the heap
This winter kick-starting technique only works if there is enough easy to compost food waste. We liken it to a human diet - if you eat a high fibre breakfast you get steady energy all day, but drink coke and eat sweets and you will be on sugar high for an hour. Since the initial heat boost from the bottle is the most crucial to get the bacteria active, they require easily digestible food during this hour.
If your HOTBIN is full of woody waste they find hard to compost, then no new heat will be generated. The hot water bottle works best when bacteria have a diet of fast food, i.e. fruit and vegetable peelings, soft plant material and nettles and comfrey, a full list can be found here.
How and Why the HOTBIN Hot Water Bottle Works
Once you know this, it is easy to identify when it will and will not work.
- Heat in a compost heap is produced from bacterial activity as they digest the waste • More bacterial activity = more heat produced
- Bacteria do not grow quickly below 5°c and not at all at 0°c
- When waste is cold only a tiny amount of heat is created by the bacteria, and this is quickly lost to the cold air - therefore cold composting heaps lie almost dormant through winter
- When you add the hot water bottle into the waste, this heat (1 litre of boiling water contains 4200 J energy as heat) moves to the colder waste
- As the bacteria become warm enough to become active, they generate heat which makes them more active and generating more heat.
- The HOTBIN's insulated walls help retain this heat - just like a thermos flask
- However, bacteria only generate heat when they have food to eat, so they need to be fed with fresh waste on a regular basis
Will a Cooler HOTBIN Turn Anaerobic?
No, the HOTBIN will continue to compost the contents at a cooler temperature and if paper and woodchip are added with the waste then there is no reason for your HOTBIN contents to turn anaerobic. However, if the contents of the HOTBIN begin to smell putrid or become saturated that is the time to become concerned about the contents turning anaerobic and to start taking corrective action.