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Banishing the Barnyard Smell: How to Tackle Ammonia Build-Up in Cloth Diapers

The dreaded cloth diaper “barnyard” stink. Have you heard of it? (or maybe even smelled it?) 

Ammonia build up on cloth diapers can present in different ways. Sometimes it’s straightforward and your diapers come out of the wash stinky. But sometimes your diapers come out of the wash smelling fresh and neutral but when your baby pees in then, the smell multiplies and is INTENSE. Both are signs that your diapers have lingering ammonia and that your cloth diaper wash routine is not working as it should.

Not to worry, this is generally a fairly easy problem to navigate if you know where to direct your troubleshooting. 

In this blog post, we’ll be focusing on a few common culprits that can result in ammonia build-up, how to properly clean and sanitize your cloth diapers if you’re experiencing this issue, and the necessary steps you’ll need to take to ensure it’s not something you have to deal with in the future.  

A little about us

We know there is a lot of information out there that can be found through a quick Google search, cloth diapering Facebook groups, or even friends and family who may have also cloth diapered! Instead of having to wade through a sea of resources, we want to bring you the most comprehensive and easy-to-follow information, that you can rest easy knowing was crafted by 'cloth diaper experts'.

What do we mean when I say “cloth diaper experts?” – well, prior to launching Esembly, we ran a busy NYC cloth diaper laundry service, where we were washing more than 15,000 diapers per week!! Yes, you read that right. Our Esembly co-founders Liz, Marta and Sarah washed tens of thousands of cloth diapers every week for over a decade! This invaluable experience not only deepened our understanding of proper diaper laundering, but it also inspired the development of our Washing Powder which was specially formulated and now holds the only patent ever issued to cloth diaper detergent. Our expert founders spent years studying the science behind washing cloth diapers and they created Esembly with the goal of making home laundering cloth diapers easy, effective, and (dare we say it) fun!

And with that…


Back to Ammonia… and the common culprits!

Typically, ammonia build-up or the “barnyard” stink, is a symptom of the diapers not getting fully clean during the wash cycle. What happens is that if a little bit of ammonia is left behind deep in the fabric, (again, maybe not enough to be stinky at the end of the wash cycle) when fresh pee hits the diaper, it reignites the lingering ammonia and the smell multiplies!

There are a few common culprits that could be impacting the performance of your washing routine, thus leaving ammonia behind:

Overall Wash Routine

Before we get down to the nitty-gritty, let’s first make sure you’re following a good two-cycle wash routine like the one detailed here on our How it Works page.

We recommend warm water with the first wash cycle, which serves to lift the top layers of soil and ammonia from the diapers and then flush it all away, preparing the diapers to be deep cleaned in the heavy second wash cycle with hot water.

If you have been washing your diapers a different way and you suspect they are not getting fully cleaned and you have ammonia build-up, first step is to switch to the wash routine linked above and see if that solves the problem.


Beyond ensuring you’re following a good wash routine to clean your dirty diapers, you also want to make sure you have a detergent that’s up for the job. (which, since dirty diapers are likely the dirtiest laundry you’ll ever wash, needs to pack a punch!)

We do recommend using our Washing Powder, simply because we find it works the best! As mentioned, it was specially formulated for Esembly diapers after years of research through our busy NYC laundering service (over 15,000 washed diapers per week!) so it's been thoroughly tested. (if you want to nerd out over the laundry science behind our Washing Powder, check out this blog post) **link to detergent blog when available. Our Washing Powder is free of all the nasty junk like SLS, SLES, etc. It is biodegradable, all-natural, mineral-based, clean rinsing, gentle on delicate baby skin, and powerful on diapers (after all, that’s what it was formulated to clean!). It also comes in a refillable canister and 6lb refill bags so even the packing was designed with planet and parents in mind!

That said, you are of course able to choose whatever detergent you’d like to wash your diapers*. If that’s the case, we encourage you to find a formula that is “clean rinsing” which means it is free of fragrance, fabric softeners and optical brighteners**. You also need to make sure your chosen detergent is powerful enough to clean heavily soiled fabric (cause again, diapers are some of the dirtiest laundry you’ll ever wash!).

*Even if you choose another detergent, we still recommend following our 2-cycle wash routine, and you can follow your detergent's instructions for measuring a normal load (1st wash cycle) and a heavy duty load (2nd wash cycle).

**The reason we caution you against using a detergent with fragrance, fabric softeners, and optical brighteners is that those ingredients are designed to live on the surface of the fabric after the final rinse. Sounds fairly benign but those lingering molecules give the ammonia and bacteria in the pee and poo something to bind to which then makes it harder and harder to wash them away in future washes.

Wash Frequency

We’re all for keeping laundry as simple as possible for your cloth diapers, but to make ensure your cloth diapers are getting fully cleaned and there is no lingering ammonia - you need to make sure you’re doing your washing every 2-3 days. If you let those dirty diapers sit for too many days, you’re inviting ammonia to set up shop, and trust us, it's a stubborn guest! 

You see when a baby urinates in a diaper, the urine contains a compound called urea. Over time, urea breaks down into ammonia, especially in the presence of bacteria. This process can be expedited in a warm, moist environment – like a wet diaper. So the longer the urea has to break down, the more ammonia is produced, which is why you might notice a stronger smell if a diaper is left for several days before washing.

Further, once you’ve got some stubborn ammonia present in your diapers, there’s really only one way to effectively tackle it. (we’ll get to this down below!)

Load Size 

​It’s important that when you wash your diapers your washer barrel is between 1/2 and 2/3 full. Any less than 1/2 and your diapers are just kind floating around during the cycle and  you’re missing out on that critical mechanical action where the diapers bump and press into each other helpful to force the soil to the surface to be cleaned away. If your washer is stuffed more than 2/3 full, your diapers are crammed in and being deprived of that essential "swooshing" action that is needed for deep cleaning.

If your diaper load is too small, go ahead and add in other household laundry to bulk it up! Just make sure that whatever you throw in won't bleed color and can withstand the hot water temps. (And try to avoid oversized items like sheets or blankets. These can tangle easily and "bury" the diapers). 

If your load size is consistently too full, you’ll want to start washing more frequently.

Hard Water 

Ahhh… the dreaded hard water!

Having hard water simply means your water has a high mineral content (magnesium and calcium generally). These minerals are not harmful to you. But they can impact your laundry resulting in cloth diapers that are not fully clean.

How does hard water affect your wash routine? Well, those minerals float around in the water and trick the detergent into thinking they are soil that’s meant to be cleaned. So instead of the detergent attacking the pee and poop in your diapers, it gets distracted by the minerals. Additionally, the minerals remain on the surface of the fabric after the final rinse and give the ammonia and bacteria in the pee and poo something to bind to (just like the 3 ingredients in detergent we recommend avoiding) making it harder and harder to wash out in future washes. 

What to do if you have hard water?

  1. Minimize exposure to the water (which means no soaking or extra rinses, etc). 
  1. Use a good detergent like our Washing Powder which was formulated to work well with soft, normal, and mildly hard water. 
  1. If you’re located in a part of the country that has hard water, or you have hard well water, you’ll need to add a water softener like Borax or Calgon to each cycle when you’re doing your washing. Adding Borax or Calgon will help soften up the water so your detergent can focus on the soil in the diapers, and not the minerals in the water. 


So, you’ve got ammonia build-up, now what? 

While it will be important to identify the culprit (or combination of culprits) so you can make any necessary adjustments in future washes, what do you do about the stinky diapers you currently have? We recommend running a “refresh” cycle. Load all of your cloth diapers and accessories into your washing machine (clean and dirty), make sure the washer barrel is approx 1/2 full, and run 2 wash cycles with Washing Powder, water softener (if you have hard water), AND (this is the very important secret ingredient) 3-5 ounces of chlorine bleach. Make sure the bleach is something very basic like original Clorox (this is not time to get fancy). Also make sure the bottle of bleach is fresh (once you open a bottle of chlorine it loses potency rather quickly).

ALWAYS make sure to pour bleach into the bleach dispenser of your washer and NEVER right on top of your diapers. And rest assured that if you’re using Esembly, all of our textiles (Inners, Outers, Day Bags, etc) are colorfast so they won’t be lightened or affected by the chlorine bleach.

Depending on the kind of washing machine you have, your refresh cycle might look something like: 

Cycle 1

Run a “Normal” cycle with 1 scoop of Washing Powder, water softener (if needed to treat hard water), and 3-5 ounces of chlorine bleach

Cycle 2

Run a “Heavy Duty” (avoid settings like “Sanitize” or Extra Hot, as these are likely too intense for your diapers) with 2 scoops of Washing Powder, water softener (if needed to treat hard water) and 3-5 ounces of chlorine bleach.

For more info check out the  “Optional Refresh” instructions here:

Once you’ve done the refresh washes, your cloth diapers should be free of ammonia and ready to go! So go ahead and use them on your baby and make sure you’ve made the necessary changes to your regular wash routine to prevent the issue from coming back! 

Keep it Simple, Keep it Fresh!


Navigating ammonia build-up in cloth diapers can be straightforward with the right approach. Ensuring you have an effective wash routine, choosing a powerful, clean rinsing detergent, and maintaining consistent wash frequency are critical in preventing the notorious "barnyard" stink. And with our laundry expertise and specially formulated Washing Powder, you're equipped to tackle ammonia issues and provide a fresh, comfortable diapering experience for your baby. Remember, a stink-free cloth diapering journey begins with preventative care and a reliable routine!


Want to learn more?

Our co-founders host a free, virtual, Cloth Diapering 101 class every month to help cloth-curious parents get all the tools and information they need! You’ll learn:

  • How to use the Esembly diapers and accessories 
  • How to easily and effectively launder your Esembly diapers
  • The impact that your choice has on the planet, your wallet, and your day-to-day. 

You'll leave with the confidence to Live Less Disposably and a 20% discount code to use on your first order. 🥳 We hope to see you there!

Sign Up for Our Next Cloth 101 Class

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