Homemade Laundry Soap – with Microwaved Ivory!

Today I used my microwave to make another batch of my homemade powdered laundry soap.

What ?? Why would I be using the microwave ??

It turns out the microwave can be an interesting method to replace the “grating of the Ivory soap” process. And if you’ve ever made a batch of homemade laundry soap, then you know the grating of the soap is the most tedious and boring part of making the mixture.

My usual method is to use my little hand grater that I bought at the dollar store and sit in front of the TV while I spend the 10 minutes or so it takes me to grate a couple bars of soap. And yes, sometimes my arm gets a little tired.

*Please don’t think I’m a wimp*

Some of my helpful readers shared with me that there are folks out there who microwave their bars of Ivory soap as a clever, fun (and kind of goofy) way to eliminate the grating.   Microwaving a bar of Ivory soap is really more of a fun science experiment and you can find plenty of YouTube videos of people fooling around and giving it a try.  It will puff way up and turn into a Ivory soap cloud that when removed from the microwave will simply crumble apart.  Any other bar of soap will melt in the microwave.

To read more about why this is click here — > Ivory Soap Science Experiment

NOW, if you’re making homemade laundry soap with a bar of Ivory, this little trick can be quite helpful.  Instead of spending your time and energy with a grater, you simply crumble up your dry puffy microwaved Ivory soap.  If you whirr the crumbly bits around in your food processor too, you get a nice powdery consistency which is perfect for homemade laundry soap.

REMEMBER – this will only work with Ivory bar soap.   A bar of Fels Naptha soap, or any other soap, will simply melt if microwaved.

Update:  I tried this with Fels Naptha soap and it can be microwaved after all!
Read more here = = > How To Microwave Fels Naptha Soap

Ivory soap in the microwave for homemade laundry soap

If you like to use Ivory soap in your homemade laundry detergents, why not give it a try?  It’s kind of fun and the kiddos will probably get a kick out of it too.

Here’s how to do it:

Microwaved Ivory Bar Soap

You will Need:

  • A Bar of Ivory Soap

  • Paper Plate or other Microwave Safe Plate

  • Microwave

Ivory soap in the microwaveUnwrap the bar of Ivory soap and place on a plate.  Put in the microwave and heat for 1 minute and watch it puff up.  Microwave for an additional 30 seconds if needed, watching carefully.

Remove your puffed up Ivory cloud from the microwave  (let it cool if necessary) and then break it into pieces with your hands.  Place the crumbled dry pieces in a food processor and process for a few seconds until powdery.

And here again is my favorite homemade powdered laundry soap recipe that’s a perfect way to put your microwaved bar of Ivory soap to good use.


You Will Need:

  • 1 box Washing Soda (55 oz)

  • 1 box Borax  (76 oz)

  • 1 bar Fels Naptha soap – grated

  • 1 bar Ivory soap – grated (or microwaved!)

Combine all ingredients and store in a container.  Use about 2 tablespoons per load.


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  1. Great tip! Your recipe is fantastic! Putting the soap in the microwave is amazing idea. I am going to try it next time. It is very important to use natural ingredients. Thank you for sharing this article. Best regards!

  2. Micorwaving the Fels Naptha really works!! I was able to crumble it with my hands and most of it fell into a powder. I had huge problems grating this soap, enough to say I would never do it again and then I saw the idea to microwave it. I was able to make a new batch of detergent in just a few minutes (after letting the soap cool).
    Thank you!!!!!

  3. Actually, you CAN microwave Fels Naptha bars just fine! I usually microwave mine for about 2-1/2 minutes. It grows a lot, though not nearly to the ivory soap scale, but stays together just fine. Note though that it seems to get hotter – you need to let it cool for longer than you do with ivory – but once cool can be broken up (it’s brittle) and thrown in a food processor. Works like a charm! I will also say that it has a stronger scent than the ivory, but I use this microwave method for either brand! =)

    1. I didn’t know you could microwave Fels Natptha! Thanks for sharing your first hand knowledge and experience. I might have to give it a try 🙂

  4. Hi there. I’m getting ready to make my second batch of laundry soap. I bought a ton of ivory on sale so will be using that again. This time I will microwave the ivory first. Last time I just grated it in my food processor, and the pieces were largish. I have had a problem with the soap not melting in the wash, thus leaving unlovey white smears on my clothes. We’re in Upstate NY and the water is pretty hard. Any other suggestions on how to prevent my clothes from looking like.I got caught in a flock of pigeons? Thanks!

    1. I think if you have smaller pieces of soap, that should go a long way in solving your problem. Using the microwave method like you are planning to do is a good strategy. You could also use a hand grater first, THEN pulse it in the food processor to give it a final grinding so it will be smaller. If your water is very hard, you could try adding a small box of baking soda to the mixture too. Baking soda helps to soften water.

  5. I microwaved Fels Naptha and crumbled it just fine. No problems at all. Mixed with the borax and washing soda…best laundry soap for us here! We have a small farm and it does the truck on every load! ( at a fraction of the cost)
    Happy Mom here!

    1. Me, too. I cut the Fels into 6-8 smaller pieces, put it on a large dinner plate and microwave it. It expands, it does NOT melt, and when it’s cool, I put it into a large Ziploc bag and crumble it with my hands from the outside of the bag. No processing needed!

  6. I just made my first batch. Can’t wait to try it tomorrow. I put the Ivory soap in the microwave and then put it and all the other ingredients into the food processor. Looks great.

  7. I grated ivory without problems in my Kitchen Tools semi-pro processor. I threw everything in the dishwasher after rinsing off what soap I could. It didn’t ruin it and I don’t really know how you could unless you get soap into the mechanics.

    It’s hard to find lye-based non-superfatted soaps. Etsy does have lye soap, but most are superfatted so they don’t work as well for laundry. Laundry soaps use a little less oil (fat from vegetable oils, lard, tallow or what not) in their mix so there is a bit of sodium hydroxide that isn’t fully converted to an ate (like sodium tallowate or cocate) with the oil. This makes it harsher on your skin, but able to attack and dissolve the fatty acids in the oils on your dirty laundry.

    Ivory and similar bars are hyper-fatted, meaning they have a neutral ph and don’t damage your skin nearly as much, but they also don’t clean quite as well.

    I found a great source on Amazon that sent me 5 lbs of lye soap flakes (about 1.5 years worth, including diapers for twins) for < $20 shipped. Maybe because of that great price, the store is no longer on Amazon. Etsy has good soap for a lot more $$, but at $15/year for 2-3 bars of good lye soap, it's probably worth it. If you do contact someone on etsy, ask if they can keep from supperfatting the soap or if they can even do a 2-4% lye deficit, which will clean better and rinse faster than oil-rich bar soaps. Sorry this is so long. But if you read this far, you maybe got something out of it.

    1. Thanks for sharing the info on “superfatting” of soaps. That makes a lot of sense and helps us understand why some soaps are better for laundry than others.

  8. I bought a cheap food processor at Kmart for $25. I use the grating blade to grate the soap bar and then put in the blade and add the other ingred to mix it well. It works great and clothes have never been cleaner. I use the 3 bars of fels naptha and borax and washing soda.

  9. Wow! can i microwave w/out the food processing after? I don’t have one, or a blender atm :/ Also, I’ve noticed your recipe uses a box of each, borax & washing soda and 1 bar of fels naptha.. Hmmm, I’ve been doin a cup of each to 1 bar of fels naptha but this seems much more cost effective. does it clean as well? I haven’t used the ivory yet. This is my 1st batch with it and going to mix w/cpl spoons of whats left of my other recipe. Hope this works because I’m real low and can’t wait today. Just got back from dropping my son off at college and made him last mixture of my recipe w/last bar…

    1. You don’t necessarily have to put the microwaved soap in a food processor or blender. It just helps to make it into a little finer of a powder. I’ve found that you can use a whole box of washing soda and a whole box of borax, but I’m now combining it with TWO grated bars of soap (usually one Ivory and one Fels Naptha). The only thing I’ve wondered sometimes is if it fades bright clothing so I use a pretty small scoop on loads with brighter colored clothes. I also often add a scoop of a dollar store brand Oxi Clean into a load when I use my homemade soap, especially on white loads. That seems to be pretty helpful too.

  10. I grated the Zote and then mixed some baking soda with the grated Zote in the food processor and it blended easily into the perfect consistency.

  11. Hi, thanks for posting this. I’ve always used the Fels, but tried Ivory tonight. What a mess! I’ve microwaved it as instructed – burned my hand trying to crumble it, and gotten one big new donut-shaped bar of soap from trying to grate it in the food processor.
    What am I doing wrong???
    (ps – Ive always done the Fels in the food processor just fine after softening it for 15 sec in microwave and then slicing it into pieces)

    1. Sorry this didn’t work out for you Kathryn. Perhaps you have a higher wattage microwave?? I didn’t crumble my microwaved Ivory straight from the microwave either because I was taking pictures of it (ha!), but I think I will add to the instructions to be sure to let it cool before crumbling. Perhaps that also helps it crumble better in the food processor too. Thanks for the tip on softening the Fels Naptha. I will definitely be remembering that one.

  12. Is this safe for sensitive skin? I usually use All Free and Clear, or Arm & Hammer Free and Clear so I need to make sure it won’t make my son and husband breakout.


    1. Before I started making my own laundry soap, I always bought the Arm & Hammer brand (usually their “Free” for sensitive skin) because my son was prone to breaking out in hives any time I tried to change laundry detergents. My son is a young adult, but still at home with us, and he uses my homemade stuff on his laundry now too. He has had no skin issues with either the Ivory soap or the Fels Naptha. I think Ivory soap is the more gentle of the two, but the Fels Naptha seems to be more powerful for laundry cleaning.

      Every person is different so I can’t say for sure if your family members would have the same results with their skin, however it was encouraging to me to see that my son has never broken out in hives when we’ve used the homemade laundry soap, nor has he complained of any other symptoms. For that reason I never experimented or looked any further for a recipe that was “Free” because he had no issues with the ones I made.

      Some people make a liquid laundry soap using the castile soaps because they are a more natural vegetable based soap, and the thought is natural = better for you. However I have also read where some people with skin sensitives have problems with castile soap. Nevertheless, it might be worth a try for your family.

      Also, if you know of some other brand of bar soap that your family is able to use with no skin problems, you could try substituting that for the Ivory or the Fels Natpha in a homemade laundry soap recipe.

  13. Do you have a recipe for laundry detergent that is “free”. Both my son and husband are highly sensitive to the regular laundry detergent.
    PS – I just made your furniture polish and it’s wonderful!!!

  14. Hi Bev!
    I hadn’t been interested in making my own laundry detergent until I read this. It sounds like fun!
    I’m wondering if you can also grate the Fels Naptha with your food processor? If it can handle grating carrots, maybe it can handle soap?
    (I don’t know if I dare try it with my brand new food processor, though…)

    1. I have a friend who ruined a food processor trying to grate her soap so you do have to be careful. I always grate my Fels Naptha first and then put it in the food processor to make it a little finer. Another option is to watch second hand stores or garage sales for a food processor so you have a spare around the house that you didn’t invest much money in. Then you can use that food processor instead to experiment with grating soap.

  15. I have seen microwaving Ivory soap on Pinterest as a kid activity, but I didn’t know there was actually something useful to do with it. I have never tried making laundry soap, but maybe I will give it a try. We certainly use a lot of it with two boys!