Churning vs. Churnless Versions

What is the difference?

The C-Head toilet is available with two options regarding the processing of solid waste. The churning version and the churnless version. One has a churning mechanism to move the medium around (medium = sawdust, wood shavings, peat moss, coco coir, etc.). The churnless does not. Each has its advantages and disadvantages over the other. The difference in cost is $35 with the churnless version being cheaper, so if you are uncertain which version would work best for you, we suggest you get the churning version and modify it into a churnless version for testing. You may want to convert the systems back and forth depending on who is using the toilet. For example, if you are having guests who are not used to using a C-Head, you may want to use the churnless version during their stay for a couple of reasons. So let’s look at the differences.

Churning version and churnless version

By far and away, we sell more churning toilets to our customers. Churning toilets have a shaft inside the solid waste bucket with a single blade at the bottom. The shaft is turned using a crank handle that is inserted into the top of the toilet seat lid and rotated clockwise. The blade, which is buried in the medium, creates a wave like action when turned and that rolls the solid waste into the medium, forming and covering it on all sides making the process extremely efficient as well as using less medium. The medium wicks off the surface moisture which would normally escape into the air and create the smell we don’t like. With the churning toilet, you “charge” the solid waste bucket with medium (sawdust, shavings, peat moss, coco coir, etc.) after emptying it out and then usually you don’t have to add more medium again until you empty it out and recharge it the next time. If you choose not to vent the toilet and the contents are becoming damp from moisture, you can add more medium to absorb the excess moisture or you can empty the solid waste bucket and recharge it.

Permaculture composting

Because the churning version uses medium much more efficiently than does the churnless version, if you are in a situation where using or carrying a minimal amount of medium is desired, then churning is your best choice. This would include living or traveling extensively aboard boats, schoolies, RV, or travel trailers, or tiny houses. It is especially suited for boondocking, and most prepper bunker situations. If you are going to store your waste and bring it home for composting or other processing methods in a permaculture setting, then the churning version is definitely what you want to use. Also the churning version is a better choice in any situation where the users may have difficulty getting medium from its storage container into the toilet without getting it all over everything, more specifically children or handicapped people. Using a dispenser like a canister will help in this regard but requires loading the canisters beforehand. Churning is more efficient because it covers the waste completely with less medium and covering the waste is important in odor control.

The churnless version on the other hand, must have medium added to cover the waste after each use. There is no churning mechanism inside the bucket. This can be an asset because you can line the bucket with a plastic bag which can be removed easily and is a much cleaner operation overall. Commonly, the waste is disposed of if it is collected in a bag but it can be bagged in compostable bags for composting. Additionally, the churnless version is more forgiving if some urine gets mixed in with it, because added medium covers the urine and contains the smell. A churning version will bring the urine soaked medium back up to the top where it can create a smell. In either case, if this happens, the solution is to simply empty out and recharge the solid waste bucket. If you are going to use the toilet in an application where there will be many first time users (guests), then the churnless version might be the best choice. There is a learning curve with using a urine diverting toilet, so if you have frequent guests using the toilet, consider the churnless version.

Simple painted concrete block docking station with medium canisters for a churnless toilet.
Suitable canisters for dispensing medium

So the churnless versions are best for weekend campers and boaters where the toilet will not be used for longer term storage of the waste. It is also ideal as an emergency toilet for people living in areas prone to power outages
from natural disasters like hurricanes, wildfires or earthquakes, resulting in infrastructural failure of sewage systems. Basically it can be used anywhere you would use a cassette type porta-potty. The C-Head has the advantage of easier management and the ability to hold more volume as well as the familiarity and comfort of a regular sized toilet.

You can convert a churning version into a churnless version temporarily by simply putting a 3.5 gallon bucket inside in place of the 5 gallon bucket in the basic models or by taking a bucket of the same size in any model and cutting out a half moon section of the rim to accomodate the urine funnel. You would need to replicate the same cut out half moon found in the existing churning bucket. Be careful not to make it smaller as it may damage the urine funnel if it doesn’t fit. Use canisters to pour or sprinkle medium over the waste. Again, this makes a good system for when you have people who are unfamiliar with using a urine diverting toilet.

It is important that the solid waste get covered almost completely to prevent odor from escaping. This requires more medium than does the churning version since you have to keep on adding medium until the waste is covered. There are numerous wide-mouth containers on the market that will work well for dispensing medium to cover the waste. You can also use a wider range of mediums with the churnless system, from coarser material like Tractor Supply Fine Pine Horse Bedding or pine pellets which make a much finer sawdust. With the churning version, fine sawdust or other very fine mediums, tend to make churning more difficult as the toilet fills up. This is not an issue with the churnless versions. You should experiment with different mediums and find out what works best for you.

Custom C-Head with notched backside to accommodate an irregular wall

One other advantage of the churnless version is that it allows for more custom modifications for tighter spaces. With churning toilets the churning mechanism dictates much about how the design can be modified. That is less the case with the free forming possibilities of the churnless versions.

Please feel free to make constructive comments or ask questions below.

Copyright 2019 – C-Head LLC – All rights reserved.

11 thoughts on “Churning vs. Churnless Versions”

  1. Can you use the churnless like the Separatt Compost Toilet and not use any medium and use just the fan to dry the poo out and keep the smell down?


    1. Hi Cate. The fan that the Separatt uses is relatively powerful and requires electricity and a large diameter vent pipe to work which makes it impractical for many compact toilet installations. The smell that comes out the end of the pipe must be directed away from the premises outside but if you have been around toilets that use this forced air ventilation system, you know that occasionally the smell finds its way to your nose outside. The C-Head uses a carbon based medium to cover and absorb the surface moisture instead of pulling the moisture out of the toilet directly. With the churnless version, there is no smell other than the medium if the waste is covered even fairly well. That is to say, it doesn’t take much medium. No smell can be detected when the toilet is closed. If you wanted to attach the same size fan and diameter pipe to a C-Head, it should work just as well as it does with the Separatt since the systems would be fundamentally identical. If I were going to do this, I would run the optional 1.25″ vent line that comes with the C-Head into a larger more powerful 3″ vent pipe stack (PVC sewer pipe painted black) with as short a run as possible. I am going to do an article on ventilation soon, so keep an eye out or subscribe to get a notification.


  2. Sorry, another question. Can you take the churner thing off of the bucket to make it into the churnless. In other words, are the churn parts removable? Also if you do use the churnable toilet as a churnless, how do you plug the crank hole so no odor excapes or bugs and stuff go in?


    1. Yes, you can remove the churning mechanism and convert the bucket to a churnless version, but I don’t recommend it. An easier solution is to just take a 5-gallon bucket and cut a half moon slot out of it that resembles the part removed from the churning bucket using a saber saw and use it instead. Or purchase a 3.5-gallon bucket online or some Home Depots or other home improvement stores carry them. They will normally fit in place without modification. Be careful that the underside of the urine funnel is not resting on the rim of either the modified 5-gallon bucket or the 3.5-gallon bucket. Line the bucket with a compostable plastic bag to make cleaning easier.


  3. You stated in the FAQ’s that the waste would need to be changed about once a week with 2 people using it. Does this still apply with using churnless? Or does it last longer/or less time. Thanks


  4. It should be about the same. There are some mitigating factors in both cases. Vegans tend to produce more waste so they may have to empty the bucket a little more often.


    1. Other popular composting toilets (based on the same vent and churn principles) claim with typical use a couple can go about a month without emptying. Why the difference?


      1. There are a couple of reasons. First the toilets and their collection containers are larger overall, meaning taller (20″+), wider and deeper. Some like the Sun-mar are substantially larger, so they do hold more so consequently there is a longer time between emptying. Secondly, they are advertising an optimistic number. Many of the comments and videos online by owners don’t support that number but rather 2-3 weeks if it is the only toilet they use. Often in mobile applications, such as boats or RVs, people will use other outside toilets when possible or convenient which extends the emptying time of any composting toilet and people in this situation are not going to contest the manufacturers claim. Thirdly, they do reduce the solid waste contents of the toilet by mashing the waste into the medium using a dough mixer type system which releases the moisture in the solid waste so they require a continuously running fan and ventilation system to draw off the moisture. The C-Head does not normally require any ventilation due to the way it processes the solid waste by thoroughly covering it with medium rather than mashing it into the medium. In some situations it may be desirable to ventilate the C-Head toilet to help control condensation for extend usage between emptying, but it is usually not necessary. And fourthly, how much solid waste a person produces varies greatly from person to person. Larger people vs smaller people, vegans vs meat eaters, etc. The point being, the holding capacity of the toilet it going to depend on the user as much as the size of the toilet itself. The number is put out there to play on peoples natural aversion to dealing with human waste. You would think the longer you can wait the better. But simplicity and ease can trump frequency.

        A few things to point out; first, the C-Head is very simple and easy to empty and does not require disassembling the toilet from the floor into parts and carrying a heavy container outside to empty in case you spill any when pouring it out. This compensates significantly for the slightly more frequent need to empty it, which is actually only about twice as often as the larger composting toilets. Processing the waste by covering it with medium, instead of mashing it up, allows for virtually 99% of all of the waste to pour freely out of the collection bucket. Owners of the dough mixer type units often find they don’t like that fact that they cannot get all of the waste to come out of the container because it gets packed into the corners. The manufacturer states that this is a good starter for the next batch of compost. The fact is no starter is ever needed since few people are going to leave the toilet unused for a long period of time to compost the contents completely inside the toilet anyway.

        And finally, there is no advantage to storing solid waste inside the toilet for long periods of time if it is going to be that much more difficult to empty when the time comes. In fact, it invites infestation by flies giving them time to develop through a normal cycle. It is better to empty the toilet regularly and more frequently to prevent this.


  5. Thanks for the thorough explanation. As an a product designer I’m keenly aware of easy of use/intuitive to use issues. If it’s not easy to do people will generally avoid doing it… Especially when it comes to poop!


  6. My C Head will be in my shower and will be too heavy for me to remove to bathe. Is there a waterproof cover available ? Like a giant shower cap?


    1. We did research the idea of making a cover but never followed through for several reasons. We do offer instructions on how to seal your C-Head for shower seat use. Be sure to add or ask Eric to add the site window glass to your order. We used to sell and install a sealing kit but our gasket supplier switched to an inferior product and we haven’t been able to find a reliable gasket material since. You could cover the toilet with a plastic trash bag while showering but I recommend having a cover made or making one out of Sunbrella or some other durable, waterproof material. You might be able to find a small cover that will work in the barbeque section of your home improvement store.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.