Do You Have Detergent Build-up in Your Cloth Diapers?

By April Duffy •  Updated: 03/08/22 •  11 min read

I’ve written about detergent build-up cloth diapers before. In my post about the problem with Fluff Love University detergent index recommendations, I talked about Emma, a first-time mom who invested in cloth diapers to save money. Like so many of us cloth diaper users, Emma had no friends and family to support her, let alone offer guidance, so she had to turn to the internet for wash and care advice.

Pretty quickly Emma found what looked to be an awesome resource, the Fluff Love University (FLU) Detergent Index, which gave her an almost complete list of detergents, told her which were good and which were bad, and even gave her the amount to use for each detergent listed. 

Emma was impressed with all the work that went into that site and the attention to detail. She also wanted to prove all of her naysayers wrong. Determined to succeed, she followed the FLU instructions to the letter. This is why Emma was so confused when her diapers began to stink (badly) and her baby is started to get rashes. 

Emma felt like a failure, but the truth was that it was bound to happen.

A lot of the advice cloth diapering beginners get online around washing cloth diapers today, especially on Facebook, leads to detergent residue buildup problems. Advice like:

While I’m certain it’s all well-intentioned advice it leads to failure from detergent residue.

So, Do You Have Detergent Build-Up in Your Cloth Diapers?

If you’ve used Fluff Love University detergent recommendations in the past, purchased used diapers, are using a water softener with your laundry, or are having smell issues you can’t seem to solve, it’s very possible you have detergent build-up in your cloth diapers. I recommend testing your cloth diapers for detergent build-up if any of those scenarios sound like you.  

After all, knowledge is power. 

Why Is Detergent Build-up so Bad? 

While Fluff Love University claims detergent build-up is a myth, I am constantly helping moms deal with the stink and rashes that come from it. As soon as the detergent (visible through suds) is gone, so is the stink and rash problems. It’s also well known to be a problem by the detergent industry itself. 

As Mary Gagliardi, a scientist at Clorox, explains in this Readers Digest article, using too much detergent can lead to a ton of problems including stains and residues on clothes, smelly washing machines, wetter clothes at the end of the cycle,  increased wear and tear on your washer’s pump and motor, and of course an increase in the bacteria left on your laundry. 

Much of the problem is that too much detergent in your washer causes too many suds. 

Tide’s website states that:

“Too many suds prevent a good wash by cushioning the clothes from rubbing against one another – it’s this rubbing that helps the clothes get as clean as possible…. Not only does oversudsing affect your washer’s efficiency, but excess suds can also prevent some of the impurities from being completely rinsed out of the machine properly. This means that impurities can redeposit onto your clothes, resulting in odors or machine malfunctions. 

“Too many suds can also block up the system, which can prevent the washer from pumping out water and, in turn, cause more suds.”

Too Many Suds in the Washer.

It’s both the redepositing of bacteria and feces/urine onto your cloth diapers and the detergent particles still on your diapers that can cause irritation to skin, and of course that tell-tale ammonia stink

Should My Cloth Diapers Smell Like Detergent?

While ammonia smell is absolutely an early warning sign of detergent residue, there’s also another smell to be slightly concerned about — a strong detergent scent.

Should clean cloth diapers should smell like detergent out of the wash? Not usually. Out of the wash, your cloth diapers should just smell clean. A super-strong detergent scent could mean that your detergent isn’t all being cleaned away and it’s being left on the surface of the cloth diaper, which is the start of build-up.

Of course, this can vary by brand as some brands, like Gain, for example, put extra fragrances in to mask smells. Even with those high-fragrance brands however your clean diapers shouldn’t smell strongly of detergent.

A strong detergent smell is a good reason to test for detergent build-up just to be safe.

How to Test for Detergent Build-up

Of course, not all rashes and stinky cloth diapers are caused by detergent build-up. Products like petroleum and zinc, fabric softeners, and infrequent washing (leading to bacteria build-up) can all cause your diapers to not get fully clean and thereby start to stink and harbor bacteria. 

Diagnosing the problem is an important step to solving it. While a strip can fix the damage of many of these issues, the problem will return again and again if the root cause isn’t fixed. 

There are two ways to test for detergent build-up, they are: 

1. The Swoosh Test

This is the easiest test for detergent build-up. You simply fill up a glass bowl with warm water, submerge a clean and dry diaper in it, and after a few minutes swoosh it around and squeeze it out a few times. If white film and/or bubbles (suds) gather along the sides of the bowl, you’ll know your wash routine wasn’t able to get all of the detergent out of the diaper, and you have build-up. 

Swoosh Test for Cloth Diaper Detergent Buildup

2. The Extra Rinse Test

For this test, you’ll be using your washing machine and a full load of dirty cloth diapers instead of a single clean diaper and a bowl of water. 

This test is great when you’re down to your last few diapers and you don’t want to sacrifice a usable cloth diaper before you have a chance to do a load of laundry. This test is NOT RECOMMENDED if you’re using a washer that’s not yours and/or one you don’t normally use. This is because while you’ll be seeing any detergent build-up on your diapers, you’ll also be seeing any detergent build-up that might be in the washing machine itself. 

To do this test, put your load of dirty cloth diapers in, and wash using your usual cycle, your normal detergent amount, etc. Once the final rinse has been done, restart the machine on an additional “rinse and spin only” cycle. Allow the washer to fill and begin agitating for a few minutes, then pause it and take a look inside while it’s full of water. If you have suds you’ll know that your regular routine wasn’t able to rinse all of the detergent out of the diapers, and you likely have a build-up problem. 

If you try these tests and you don’t see very much film or suds, but you’re still having rash and or smell issues, you’ll know that something else is happening and you can knock this one off your list. 

How to Remove Detergent Build-up

If you do find yourself with a detergent build-up problem, you’ll want to take the following three steps to fix the problem and reset your cloth diapers:

1. Clean Your Washing Machine

Unfortunately, if you’ve been regularly using too much detergent, it’s most likely that not only do your cloth diapers have detergent build-up on them, but you have detergent residue lining your washing machine as well. 

In fact, if you’re only following the recommended amounts on the detergent bottle for your diapers, and using too much in your regular laundry, the problem could very well just be with your machine having build-up that’s depositing on your cloth diapers.

Recall the Tide website said that too much soap can block the system, preventing the washer from pumping out water and, therefore causing more suds.

How to Get Rid of Suds in Washing Machine

To clean your washing machine, you can use a commercial cleaner like Affresh (Amazon Link), or simply run a full cycle (some machines do have self-cleaning cycles) with hot water and a cup of vinegar to cut through the detergent. 

This of course only applies if you’re using the same machine all of the time. If you’re using a commercial laundromat or traveling etc. this step will be fruitless for you. 

2. Rinse Your Diapers Clean

Once your machine is clean, it’s time to tackle the diapers themselves. The detergent that’s built up on them needs to be cleaned away completely. The quickest way to do this, though it can take some time, is to rinse them until the water runs clear.

Again, this can take some time. I once coached a mom though having to rinse out so much build-up it took 14 rinse cycles and two strips to remove it all!

Should You Strip your Diapers to Remove Build-up?

In the past, I’ve recommended stripping your diapers to help remove detergent residue but after coaching literally thousands of parents through the process I’ve found it’s largely unnecessary. Rinsing the diapers thoroughly, perhaps using some vinegar in the rinse (you can read all about vinegar for cloth diapers here), is often all that’s needed.

If however, you’re removing buildup from used diapers, or are skeptical that there may be other build-up on the diapers—like fabric softener or diaper creams—stripping can also be done. You can read my full post about how to strip diapers here.

After doing a strip you’ll still likely need to rinse them and continue rinsing until you don’t get any suds through either of the tests mentioned above, this could take several rounds of rinse and spin cycles or time spent at a faucet rinsing and squeezing until the water runs clear.

3. Adjust Your Wash Routine 

Once everything is clean and clear of soap build-up, adjusting your routine will be vital to avoid the problem from happening again. 

The first step is to reevaluate how much detergent you’re using. Make sure to start with the recommended amount for heavily soiled loads of laundry, on the bottle/box of detergent you’re using for your load size. From there you can add more for some situations/needs and reduce it for others.

I am being pretty vague here, but that’s because the topic of next week’s post, the third in this series, is going to be all about how to help you figure out how much detergent to use, so check back here for that soon. 


Laundry detergent residue from using too much detergent is very much a real problem and even acknowledged by detergent makers themselves (see quotes from Clorox and Tide above).

When detergent residue sticks onto a cloth diaper, the dirtiest and most multi-layered laundry you’ll ever wash, it causes more problems than dull and stiff fabric, it causes bacteria build-up, stink issues, and eventually rashes. It can also be very bad for your washer. 

To test for detergent build-up you can either test a single clean diaper in a bowl of water or perform an extra rinse in your washer as laid out above. If you’re using multiple washing machines or a laundromat to wash your diapers, the swoosh test of a single diaper will be best for you. 

If you find that you do have detergent build-up you’ll need to reset your washer and your diapers by cleaning them thoroughly (instructions on how to do that properly are above). Once you’re back to ground zero, you’ll need to adjust your wash routine to keep the buildup from happening again. I recommend the Measure Method for cloth diaper laundry, which I outline here.  

The Measure Method of washing cloth diapers helps cloth diapering parents work out how much laundry detergent is appropriate for how many cloth diapers they’re washing at a time, their water hardness, and their preferred cloth diaper detergent. It also makes sure they don’t overload their washer with too many diapers, which can

The Next Step

In it, I take you through how to calculate the proper amount of detergent you need for your unique needs including your preferred detergent, your washer size, and your water type.

April Duffy

April is the founder of Cloth Diapers for Beginners and author of The Cloth Diaper Wash & Care Handbook. Since 2015, April has helped well over 75,000 parents and caregivers cloth diaper their children through this website, her book, her YouTube Channel, and the Cloth Diapers for Beginners Facebook Group.