Homemade Laundry Soap

I've been trying for a couple years now to make all our own cleaning products. I've succeeded fairly well with cold process hand & body soaps.

Clean, Naturally: Recipes for Body, Home, and Spirit by Sandy Maine is a great start for basic soap making. (This is an older book and is now out of print. Newer books have since been published. And now of course there is a proliferation of soapmaking blogs.) 

Vinegar, baking soda and borax work for most household cleaning. Add a little Dr. Bronner's (we like peppermint, though tea tree sounds great too) when you want a liquid cleaner for floors or toilets. 

I am now making our own laundry soap and it's a bit complicated so it may not be for everyone. But a friend asked me how I do it and I thought I'd share it here.

First, I make a batch of cold process soap. This is the hardest part. I have a tutorial called 4 Steps to Making Homemade Soap to get you started. You could also watch my video tutorial How to Make Simple Soap.

Once I make that Simple Soap I mix it with borax and washing soda. Voila. Laundry soap.

Simple Soap:

  • 4 lbs of lard or vegetable shortening
  • 28 oz water
  • 8.5 oz of lye

When the soap is ready (takes about a month to cure) I grate most of it in the food processor, saving some for basic cleaning bars.

Laundry Mix:

  • 12 cups washing soda, not the same as baking soda
  • 8 cups borax
  • 6 cups grated Simple Soap


I use cold water wash and rinse. For an extra large laundry load I use 1/2 cup of laundry mix. The Laundry Mix doesn't dissolve well in cold water so I whisk the 1/2 cup with 1 cup or so of hot water to help it dissolve before I add it to the washing machine.

For stains I scrub and lather a bar of Simple Soap into the stain, or soak in a concentrated solution of water and Laundry Mix. I'll be honest, our clothes get stained and all the scrubbing in the world doesn't take some of them out, oh well.


You can use any bar soap to make this recipe. I have also made laundry soap with failed soap batches. If a batch of soap doesn't turn out, especially if its caustic and not moisturizing for our skin, I grate the soap as I would simple soap and make it into laundry soap following this recipe.

More FIMBY make-your-own recipes:

Laundry Soap Recipes from Other Blogs:

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  • Julie

    Julie on June 21, 2008, 3:47 a.m.

    I have had pretty good luck making Castille soap (similar to the Lard soap, but with olive oil instead of lard!) and I bet you could use this for your laundry soap. I refuse to mess with lard, and since you mentioned you thought it was nasty stuff too, I thought you might like to try the Olive Oil kind.

    We also make hand soap with the Castille soap and have added everything from avocado to cocoa butter to coffee grounds (to remove kitchen smells like garlic from your hands)--it's pretty neat stuff!

    :) Julie


    • renee

      renee on June 22, 2008, 2:03 a.m.

      Thanks for the tip Julie. I like the hardness of the lard bar but I might have to try Castille soap next time.


  • Leigh Ann

    Leigh Ann on July 21, 2009, 5:17 a.m.

    Where can I find washing soda??? I don't know where to start looking for it. thanks!


    • renee

      renee on July 21, 2009, 11:21 a.m.

      I find it in my local grocery store, Hannafords, next to the Borax in the laundry soap aisle. It's up high, out of the way. I've read about people who have troubles finding it and will drive to get it. Hopefully you don't have to do that.


  • Karen Harris

    Karen Harris on Sept. 14, 2009, 12:15 a.m.

    The thing I can't find is the lye. Where do you find that? Would I be able to get some from you perhaps?

    Thanks for all of these homemade recipes. Your soap looks incredible. Wish I could buy it.


    • heather

      heather on Dec. 10, 2009, 5:30 a.m.

      I make my own soap,and I use camdengrey.com for my lye source. They are the best price I have found so far. Good luck!


  • Nick @ All Washing Machine Reviews

    Nick @ All Washing Machine Reviews on March 3, 2010, 5:12 a.m.

    I have read somewhere before of a homemade detergent method using 1 bar of laundry soap like Fels Naptha or Zote and it work very well - it cleaned my clothes just like highly concentrated detergents. But it did not work for my uncle's top loader.

    So will give you recipe a try see how it turns out,

    Thanks for taking time to share your tips with us.


  • Sarah

    Sarah on June 10, 2010, 5:50 p.m.

    I really want to try your basic soap and laundry soap recipes! I have followed the links that you posted and have been reading up and gathering supplies...but I am still figuring things out like-- at what temp do you mix your oils and lye solution? and how much soap does this make?


  • renee

    renee on June 11, 2010, 1:14 a.m.


    I'm so happy you've found FIMBY to be a valuable resource for you.

    I usually mix my lye and oils at 100-115F. The most important thing is that the two mixtures are the same temperature. I've never deviated too far from this advice to know how wide the margin of error is for this.

    I can't say how much soap this recipe particular recipe makes, I don't remember. However, I have started to keep track of other recipes to I can standardize my recipes a bit more. 

    Here are some of my calculations from a recent recipe:

    wt of ingredients: 139 oz

    wt of soap one day after being mixed, ie: weighed when coming out of the mold and being cut: 140 oz (essentially same as above number)

    wt of soap after curing 4 weeks: 120 oz

    loss of 13.95%

    I don't know if these calculations would apply to other kinds of soap as well. I am keeping track from now on to find out for myself.

    Hope that helps some for you.


  • Anonymous

    Anonymous on June 18, 2010, 2:45 a.m.

    I'd like to try this sometime to wash my clothes. I'm just a bit hesitant though, because I've been told that homemade soaps can leave grease stains on clothes (from oils in the lard and such). Then again, it seems to work for you. Do you think store bought bar soaps (the natural ones in health food stores) would work as well?


    • renee

      renee on June 18, 2010, 1:35 p.m.

      I honestly have no idea. I have not had problems with grease stains on our clothes. I use a bar of simple soap to hand scrub difficult stains and they usually (unless they are really set) come out. For me, some stains are ok (my kids where their clothes hard) in exchange for earth friendly, skin friendly homemade soap.


  • Laura

    Laura on Dec. 4, 2010, 1:24 p.m.

    I've been using a homemade liquid laundry soap in my HE machine for about a year now, I think your cold pressed soap would be great in it! I use 1/2 cup per load, works out to about a penny a load. I make a double batch about every 5 months, we love it!


  • Colleen

    Colleen on March 24, 2012, 4:14 a.m.

    Does anyone know if this is safe to use when you have a mound system septic like I have? They can be a little finicky and VERY expensive to re-do them(10K). I would like to use this soap in the laundry but cannot find the information regarding safety in septic systems. We process our own lard and make soap for other things and I do like the ease of your directions.


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