Tuesday, July 11, 2017

Suint Fermentation -the best way to clean raw wool if you want to save water

Suint Fermentation

to clean raw fleeces: some of the science behind it, why it works, and how to do it yourself.


Cleaning raw fleeces can be an extremely tiring and grueling process. Depending on the breed and how dirty the individual animal was prior to being sheared, you can often have an extremely daunting mess on your hands.

In addition to it being extremely labor intensive, cleaning raw fleeces from start to finish is also a smelly experience that is not for the faint of heart -- regardless of which method you use to clean it.

That leads us to your cleaning options: There are a lot of different methods that you can use to clean a fleece, and some are better suited to specific fleeces than others. 

If you have a smaller fleece, or one that is rich in lanolin, then it may be best to go ahead and clean it in your sink using a wool wash. My favorite is Beyond Clean, as it works better than
any other wool wash I have tried, and it is very reasonably priced. Even after cleaning a fleece using the Suint Fermentation method, I will still finish up with one soak in a sink with warm water and a squirt of Beyond. This helps finish up the cleaning process and make it look beautiful.

For larger fleeces, or extremely dirty fleeces, I prefer the Suint Fermentation Method of cleaning (also called the FSM, or Fermented Suint Method). When we get our Teeswater fleeces, they come unskirted. They are extremely heavy, and dark brown with dirt (keep in mind that it takes a sheep an entire year to grow their fleeces this long, and sheep don't take true baths besides being rained on). It usually takes 7 or 8 rinses (prior to the actual washing!) to get these fleeces clean enough to use soap on. These fleeces are perfect for this method, and that's what I'm going to talk about today.

As many of you know, I was an Environmental Science major (previously a microbiology major... I love science!) and I really dislike wasting water. In a search for a better way to clean these fleeces without using as much water, I came upon the perfect solution -- The Suint Fermentation method. This method works particularly well for large batches of fleece, which are low in lanolin content. 

The Science Behind Suint Fermentation

*Skip this section if you just want to learn how to actually clean the fleece! 

Throughout their lives, sheep draw potassium chloride into their bodies as they graze. This chemical is commonly referred to as "potash." Sweat on its own is a mix of mostly water, combined with trace amounts of lactic acid, urea, and minerals. Together, a mixture of excess potash combines with their sweat and builds up on their wool. At this point, it becomes a soluble salt, and this compound is collectively referred to as "suint."

Some breeds of sheep have quite a lot of suint built up in their wool (Merino sheep, for example: approximately 1/3 of their wool weight is made up of suint and washes out when the wool is cleaned!). Typically the finer the wool, the more suint will be present in the fleece. In coarser sheep breeds, only about 15% of the weight is made up of this compound.

In addition to the suint in a sheep's fleece, there is also a greasy matter called Lanolin, which combines with lime and other earthy matter to create an insoluble soap.
When a fleece is washed in this way, you are pulling out these natural soaps from the suint, as explained above. But instead of rinsing and immediately drying the fleece, it is given extra time in this all natural soap bath, where the bacteria present on the fleece can go to work to help with the cleaning process. Soaks alone are usually not enough to get rid of chunks of poop and dirt, but the bacteria present in this additional step  are able to eat through this solid matter in a very efficient way that could not be achieved by soaking alone.

The bacteria involved in this process are anaerobic, which means that once the fleece is out of the water and in an oxygen rich environment, they die and therefore the smell goes away.

In Anaerobic cellular respiration electrons are extracted from a fuel molecule and are passed through an electron transport chain, which drives ATP, T, P synthesis (ATP is what makes everything work - it is the source of energy within cells). Some organisms use sulfate as the final electron acceptor at the end of the transport chain, while others use enthesis, N, O, start subscript, 3, end subscript, start superscript, minus, end superscript, right parenthesissulfur,
nitrateeft , or one of a variety of other molecules. Some prokaryotes that live in low-oxygen environments  (such as a tote full of rain water) rely on anaerobic respiration to break down fuels. For example, methanogens are found in soil and in the digestive systems of sheep, and they can use carbon dioxide as a terminal electron acceptor, producing methane as a by-product (with its characteristically bad smell). Likewise, sulfate-reducing bacteria use sulfate as a terminal electron acceptor, producing hydrogen sulfide (the characteristic gas that smells like rotten eggs). 

How to clean your fleece with this method

The first thing that you will want to do is grab a tote (with a matching lid set aside), and set it outside under a spout so it can collect rain water. Any size large enough for your fleece will do - but the standard is about a 20 gallon tote. 

You want to have a nice soft water for this method, which is why rain water is ideal. Some people cheat and use tap or hose water, but I highly recommend doing it the right way and waiting for it to rain. In the absence of rain, you could always use distilled water instead, but rain water really works best.

Corriedale after suint bath
Once you have enough rain water to fill your tote, you are ready to begin. For your very first suint bath, you will want to choose a fleece that is extra rich in suint. For our experiment, we chose a deliciously soft corriedale fleece, which was ultra sticky and rich in suint and lanolin. This is because that wonderful substance works as our all natural soap, so the more of it we have in the initial wash, the better.

Bubbles forming in the bath on day 5
Place your "starter" fleece in the tote full of water, and fully submerge it. Cover it with the lid (it doesn't have to be air tight but you will want to keep bugs out of it if you can). Set it somewhere (outside of the home is recommended) where it won't get too cold. Ideally, you want it to be in a nice warm environment. For our bath, we used our garage the first time, then moved it to the shed by the time we were on our third batch because I didn't want to keep smelling it every time I went out to the garage. We have tested many different temperatures (primarily due to the changing weather), and found that the best results came when it was super hot outside... above 80 degrees Fahrenheit.
Leave it for about a week.  Lay back and let those microbes do all the work for you!

Day 7 has a nice film over the top .
After a week, it's time to take it out. You can remove the lid and you should notice some bubbles and maybe a film on the top of the water. This is what you want to see, as it is a sign of the little microbes doing their job and producing that lovely gas that will smell quite a lot like rotten eggs. Trust me on this, the smell will be horrible. 

You will want to get another tote and ideally a screen to place over it so you can set your fleece on top of the screen to drain into the new tote (afterwards, you will want to pour that extra water back into the original tote). In our experiment, we forgot (not just once, but several times) to go buy a screen, so we just scooped the fleece out by hand. The screen is not essential, but it does make it easier because you'll want to save the water for your next suint bath. You can re-use it over and over, and the "soap" will only get more concentrated each time. It's not realistic that you'll be able to save all of the water and that's ok. It's fine to re-fill it with additional rain water as needed.  One thing to note is that this process doesn't take out all of the lanolin, and your starter fleece will still be sticky when you take it out.*

Something that you don't have to do (but we found helpful) was rinsing the fleece once after taking it out of the wash. To do this, we filled up the new tote with drained fleece from the original tote, then used a hose to rinse it off before we set it out to dry. As soon as you rinse it initially, you should be able to see the difference between your unwashed fleece and your newly washed fleece (very evident in our video). It should lighten up considerably with a rinsing, then lighten up again with your final wash post-dry.

My lovely assistant... LOL
We like to set our wet fleeces out on the deck to dry, but how you dry yours is entirely up to you. Hanging laundry baskets (like what we have in the beginning of our video) also work well, as do screens.  The fleece will smell terribly. Rinsing it will not help with the smell, but can help get some excess dirt out of the fleece initially. Once the fleece is dry, the smell will go away completely, and will not come back -- even when you get it wet again. In the picture above of our rinsed Teeswater, I added some mint leaves from a mint plant out back to help me deal with the smell. It helped considerably.

That's all there is to it. After you are finished with your starter fleece, you will be ready for your next fleece!

You will basically want to do everything that you did last time, but it should only need a couple of days (2-3) instead of a full week for every subsequent fleece that you clean in your tote. Remember that each time you run a fleece through, you are adding to the suint that is already in the bath and making that soap more potent. 

This process will not get rid of VM (vegetable matter), but it does greatly eat away at any clumps of dirt or poop in the fleece. The amount of water that is saves on extra dirty fleeces is very impressive, and it's a great way to wash a lot of fleece at once. 

Some helpful tips 

  1. Use disposable gloves when handling the wet fleece after it has been in the suint bath. The smell sticks to the material and will not go away afterwards. 
  2. Do not bring the fleece into your house while it is still wet initially. It will fill up your entire house and make it smell to high hell and back. Let it dry first so the microbes die off, then wash it one final time. Using Beyond or Unicorn as a soap works really well for your final wash, and should get the fleece really clean. Tips for how to do that are at the end of my blog.
  3. Whenever possible, skirt your fleece before you add it to the bath. It's just always going to give you a better final result than throwing an entire fleece in it. 
  4. Do not try this method if you are sensitive to bad smells. 
  5. Do try this method if you want to save water, clean fleece in an all natural way, and want to clean a lot of fleece at once with minimal effort.

A small sample of locks after they finished drying. 

I hope that this information was helpful. We have posted a video on Youtube of our initial results so you can get a better look at our process. I would love to hear how it works for you! Check out the video at: https://www.youtube.com/watch?v=zCVfRhenksE

Check us out at www.bluebarnfiber.etsy.com or www.bluebarnfiber.com 

We sell our Teeswater locks in bundles and can custom dye any colorway you can dream up!
We also love  Unicorn / Beyond so much that we sell it. It is available in our shop at https://www.etsy.com/listing/462282969/ 

Stay tuned for a custom dyed batch of Corriedale for sale from our very first ever suint bath! 

Thanks for visiting!

*In order to remove the lanolin from your starter fleece (or any subsequent fleece that has a high lanolin content), you'll need to wash it in hot water and ideally a drop or two of soap. Blue Dawn or Beyond / Unicorn Power Scour work wonderfully for this. Fill up a sink full of hot water, add the soap, add the fleece, let it soak (do not agitate it at all), then drain it after a few minutes while the water is still hot. Fill it up again to rinse it, then drain it again. Set it out to dry, and you're done. The hot water sort of melts the lanolin, so letting the water get cool will cause it to re-solidify on the wool. Or, you can choose to keep the lanolin on the fleece and use it as-is. A lot of people love the way it feels and it is added to many beauty products after being harvested from wool. It's an all natural lotion.  For other fleeces that are not heavy in lanolin: You will want to wash them one final time after the initial dry. You can use the same method as above, but you can use either hot or warm water and either one should work fine.


  1. Wow! I am going to try this. I have a "practice fleece."

    Thank you very much.

    1. You are very welcome! It's a smelly process, but I love how much water it saves. And it works really, really well. Hope it works for you!

  2. I have some pretty dirty Shetland wool that i was gifted. I raise Suri alpacas so am not used to lanolin. How can I tell if the Shetland has enough lanolin for this method? Also, thinking about doing this in my greenhouse now that the plants are out. Can it get too hot?