Laundry Soap Overview

the best laundry soap is custom-made for your needs!

© 2012 by KV5R — Rev. April 5, 2012.

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Recently I read several articles about “homemade laundry detergent.” They all go about like this: “Grate up a bar of Fels-Naptha, Zote, or Ivory soap into two gallons of hot water, add a cup of Borax and/or Washing Soda.” But I’m wondering exactly how grinding up a bar of commercial soap and adding some laundry booster is “homemade” soap? Well, it isn’t, it’s just pre-mixing! So I decided to write an article about real homemade laundry soap.

First, we need some basic education about laundry soap and the cleaning process. We need to understand that the your best laundry soap is one that is custom-designed for your water, not some general-purpose recipe. Then we need to actually design and make a batch and try it out.

Why Make Your Own Laundry Soap?

There many good reason why you may wish to make your own laundry soap:

  • Cost: You can save somewhere around 90% by making your own laundry soap.
  • Allergies and sensitivities: Commercial laundry detergents contain additives, chemicals, and fragrances that many people find offensive.
  • Environment: Natural soap is better for the environment. If you don’t believe it, just run your wash water on the lawn for a while and see the difference.
  • Better cleaning: If you make soap designed for your water, it should work better than commercial products, which are compromised for a wide range of water conditions.
  • Being a do-it-yourselfer carries bragging rights!

Differences Between Soap and Detergent

Detergent is not soap.

A detergent is a surfactant or a mixture of surfactants with cleaning properties in dilute solutions. In common usage, ‘detergent’ refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water.

So, there is no such thing as “homemade laundry detergent,” unless one happens to know how to make alkylbenzenesulfonates in the kitchen…

Soap, on the other hand, is saponified oils, id est, the salts of triglycerides, formed by a reaction between fat/oil molecules and an alkali (usually lye). Soap that is properly made contains no remaining fat/oil or lye—they are both consumed into the reaction. Soap is a bipolar lipid molecule. It attaches to oil on one end and water on the other, thus making grease/fats/oils water-soluble. When they are broken up, they release entrapped dirt and other particles. If it were not for oils (and organic stains), clothes could be completely cleaned with only water.

One main difference between soap and detergent is that detergent is less affected by hard water. Soap, on the other hand, works best in soft water but if you have hard water you can still use natural soap by softening the wash water.

Softening Your Wash Water

  1. Soap’s effectiveness is impeded by minerals in the water, usually dissolved calcium and magnesium. Washing Soda, Borax, and other ionic salts will grab the minerals in the water and bind with them, a process called sequestration. Water softeners may be used to bind up the minerals so they don’t interfere with the soap.
  2. There are three main types of water softeners: (1) precipitating, (2) non-precipitating, and (3) ion-exchange water treatment systems.
    1. With a precipitating softener, mineral salts (such as sodium carbonate and sodium tetraborate), a sodium-ion-something binds with a mineral-something that forms crystals that precipitate a fine crystalline powder in the laundry, making it feel starchy, and darker fabrics may look dusty (but tumble dryers remove most of it).
    2. With a non-precipitating softener (such as vinegar and citric acid) an organic (carbon-based) acid binds with the minerals (which are alkaline) but they stay in solution (dissolved), and are thus easily washed out, leaving no micro-crystalline residue to stiffen up your laundry. Thus, we can see, it is much better to use a non-precipitating organic acid water softener to make your soap work better but not leave residue in the fabric. Citric acid is the best and most commonly used non-precipitating softener for hard laundry water.
    3. An ion-exchange water softener system is by far the best solution, except that (1) they are very expensive, and (2) they put a lot of salt down the drain when the catalyst tank is regenerated. On the other hand, a whole-house water softener not only gives you the cleanest and brightest laundry, it also gives you spotless dishes and shower/tub/toilet surfaces, soft hair, lowest soap usage, clean plumbing, hot water heater lasts forever, etc.

Precipitating Softeners

  1. Washing Soda: Washing soda (sodium carbonate) is not baking soda (sodium bicarbonate). Washing soda is a little stronger alkali than baking soda, so you use less, and you get less residue in the wash. Washing soda may be found in most supermarkets in the laundry detergent aisle. Start by following the directions on the box, then as time and washings go on, adjust the amount you use per load for best results. Watch it during the agitate cycle, and when your natural homemade soap makes the most suds, that’s when you have the right amount of washing soda for your water. You can also use a TDS (total dissolved solids) meter, available on-line for about $20.
  2. Borax (sodium tetraborate): Works about the same way as washing soda, but I find that it leaves my line-dried clothes feeling starchy.

Non-precipitating Softeners

  1. Vinegar is simply a mild acetic acid, and it isn’t really strong enough to be cost-effective.
  2. Citric acid, much better, is readily available as “Lemi-Shine Original” (not “Rinse”) in stores near the dishwasher detergents. Citric acid also available in bulk. (You could squeeze a lemon into the wash but then you’d have the sticky fruit sugar, too). It may be used in both the wash and rinse cycles, but for best results, you need the right amount to soften the given water volume and hardness. As with the precipitating softeners, a digital pocket TDS meter will get you to the right amount for your water hardness. When the TDS is at or near zero, the water is “soft.” Or you can get pretty close just by watching the suds.

Ion-exchange Water Softeners

I had a RainSoft system for several years. It, along with a reverse-osmosis system under the sink, cost about $2700 in 1992 dollars. I had it set to produce about 500 gallons per week, and the salt cost was very reasonable. Clothes were bright, and dishes, sink, shower, and toilets were always spotless. If you can afford a whole-house water softener, you’ll absolutely love it! If you have one installed make sure you have at least one outside faucet before it, for watering the yard and washing the car. After you wash the car with hard water, rinse it with soft water, from a faucet that’s after the system, for a spot-free rinse. RainSoft systems come with several gallon jugs of natural liquid soaps made for soft water, and they’ll last for years since you use them by the teaspoon.


  1. Fels-Naptha: Many sites recommend this, but it’s really just a plain tallowate soap with lots of extra caustic (lye) added. It’s made for spot treatment, not laundry washing. You can do just as well spot-treating greasy spots with Formula 409 spray (also soap and caustic). Incidentally, some people think Fels-Naptha contains naphtha (note the extra h in the spelling), which is a light aromatic hydrocarbon; also known as lighter fluid, camp fuel, and white gas. Not true: Fels Naptha contains no naphthalene—it says so right on the back label. As for spot-treating with actual naphtha (lighter fluid), as was done decades ago, modern washing machines make sparks when they change cycles, and they warn you (under the lid) not to use flammable solvents, as they might cause an explosion. But I digress. Now, since we’re gonna make a much better soap (id est, one with much better cleaning properties), in water custom-softened with citric acid for maximum effectiveness, there is no reason to use Fels-Naptha, unless you just like to use a block of rub-on spot treatment (which is okay).
  2. Zote: Never tried it, but many people like it. Zote is a large (14-oz.) hand-wash laundry soap bar made with coconut oil and tallow. Zote is made in Mexico, and is readily available on-line in bulk at reasonable prices. Probably the cheapest natural soap you can buy, but still, you can make your own for even less.
  3. Ivory: A mild bath soap. I imagine it’ll get your clothes clean, but we can do better. It has a little fragrance, which I like to avoid.
  4. Real homemade soap: This is the best of all, because we can use a good soap designer/calculator (on-line or spreadsheet) with the right properties for laundry. For example, if you design a cold-process soap with equal parts coconut, lard, and olive oils, you will see a blend with a very high cleansing property and a very low sudsing property—perfect for laundry. You can see the various properties of oil blends on-line by using the soap calculator at This will be far superior than a simple lard or tallow soap, which have relatively poor cleansing properties. Saponified coconut oil is the strongest natural cleanser, and it’s only about $5 a pound.


As I said near the beginning, most of the articles on-line are how to make mixtures of some grated bar soap and washing soda and/or Borax. Since everyones’ water hardness is different, it’s probably not a good idea to simply mix up a soap and a chemical water softener. Rather, add soap according to the suspected amount of oils in the laundry load, and add a softener according to the volume and hardness of the water. To say “mix up a cup of this and a cup of that” is to use a shotgun approach and, without endless experimentation, is no better than what the commercial detergent manufacturers are forced to do. If you’re gonna make homemade soap, it might as well be made exactly to your particular needs and water condition, for best possible results and lowest cost.

Also, homemade laundry mixtures tend to gel, clump, and separate, requiring much shaking and stirring before use. If you do want to make a mix, stay with the dry mixes. First determine how much soap and softener your water needs per load, then mix up your grated soap with your preferred softener and oxygen bleach.

What About Stains?

Stains, on the other hand, are a completely different matter. Soap only breaks up oils, not organic stains. That’s why the manufacturers add enzymes and/or oxygenating compounds. The best way to deal with stains is to simply pre-treat with any good commercial stain remover, then wash. The reason is that most stains are organic (carbon-based) dyes (foods, grass, wine, etc.) and they bind very firmly with natural fabrics. Indeed, before the invention of aniline dyes (about 140 years ago), all cloth dyes were organic “stains.” So it’s best to leave it to the commercial chemists to come up with something to separate them without also removing the aniline dyes used in modern fabrics. Sodium percarbonate (e.g., Oxiclean) is probably your best bet, but I’m no expert on stain removers.


Now I’d like to address some of the “problem” questions that many readers raise in soaping forums.

  1. “Isn’t ‘lye’ soap toxic? After all, it has LYE in it!” People who irrationally fear the “toxicity” of this and that are, quite frankly, just plain ignorant and brainwashed. They don’t know the difference between a “poison” and a “corrosive,” much less a “mixture” and a “reaction.” They think if you put something in something, then it “contains” that something. Yes, if you put salt in water, you have saltwater—a mixture. But if you put two unstable things together, say, lye and fat, then you no longer have any lye or fat (if you do it right), you now have soap—something completely different than its original ingredients—a reaction. To further illustrate, we run into people who want to make homemade soap, but they fear lye, because it’s a “poison.” No: Lye (sodium hydroxide) is not a poison, it’s a corrosive; and besides, there is no lye left in properly made soap. And yes, it’s somewhat dangerous to handle in pure form, so (1) don’t get it on you, and (2) if you do, wash it off, right now! That’s the golden rule of handling corrosives. Dilution is the solution, as they say… On the other hand, commercial soaps and skin-care products almost always contain SLS (sodium lauryl/laureth sulphate) and it irritates the crap out of me and it stinks and it’s toxic. I have dozens of laurel trees here, and must avoid them like poison ivy! That’s why I make my own soap, and it’s so nice to have laundry that doesn’t burn your eyes and nose like the soap aisles in the stores. So, generally speaking, commercial soaps and detergents contain toxins and allergins, but ‘lye’ soaps do not.
  2. “What is safe for my baby diapers, allergies, etc.?” Remember: “Laundry soap is for fabrics, not skin—if you have a reaction, rinse it again!” I can’t believe how many commenters write about laundry soap ingredients as if they don’t know what the rinse cycle is for! Beyond that, properly made natural soap and natural water softeners are fine for all laundry, including baby clothes and diapers. And if you actually have an allergy to some kind of natural soap, just make another soap with different oils—but first, try the good ol’ double-rinse.
  3. “What about my high-efficiency washer?” I’d say to them, “Go get a real washing machine: the more water it uses, the better!” They save 15 gallons in their expensive washing machines and then put 50,000 gallons in their swimming pools, use 5,000 gallons washing their low-carbon cars, and 20,000 more watering their landscaping… But to answer the question, many postings say to use 1/3rd the amount of soap that you would use in a top-loader.
  4. “Should it be gloppy, gloopy, gel, lumpy, separated, dry powder, etc?” Stop trying to make buckets of wacky unknown goop and just grind up some good-quality real homemade soap (not commercial soap or detergent). Put in 2 tablespoons of that and put in 1 tablespoon of citric acid crystals and see how it acts. Then adjust as needed.
  5. “How do I grate a soap bar into flakes or powder?” The best way to grate soap is with a Presto Salad-Shooter Professional, with the grater cone. Don’t use the regular Salad-Shooter, you’ll strip the plastic gears. The Professional model (about $65) is much larger, heavy-duty, and it’ll grate a bar of hard soap in under 30 seconds with no problems. Or you can use a good ol’ manual cheese grater, if you want a little skin and blood in your soap…
  6. “Will this-or-that harm the environment?” Not if it came from the environment. Period. “Will it hurt my septic tank?” If it’s made from natural ingredients and diluted with lots of water, probably not. If it’s store-bought, read the label! If it’s chlorine bleach, yes (duh). Speaking of septic tanks, only the toilet(s) need to go therein; the sink, bath tub, and washing machine should go right on the yard and landscaping. Natural soap is a good bug repellent. The exception is washing cloth diapers—obviously then the washing machine should go into the septic or sewer system. Can you imagine how much water we could save if every home had separated sewer and gray water systems?
  7. “What about using bleach?” Why would anyone wanna do that? This is supposed to be “homemade” laundry soap! The rule of mixing bleach (sodium hypochlorite) is simple: Do not mix chlorine bleach with anything acidic, or with ammonia! It will react and release chlorine gas. And no, chlorine is not a “poison,” it’s a corrosive. If you breathe it, it mixes with moisture in your lungs, making hydrochloric acid, which burns your lungs. Not fun. Chlorine bleach (~5-6% sodium hypochlorite) degrades cotton and should never be used in cotton laundry. That’s why they came up with “bleach alternatives” like Oxiclean and Oxy-Boost. Walmart has the 10 pound box of Oxiclean for about $14 and that’s probably the best you can do on a small quantity. You can also buy powdered hydrogen peroxide (sodium percarbonate) on-line in bulk, about $1/pound for 1000 pounds, a fraction of the cost of commercial brands, and a viable option for group or institutional purchases. Anyway, chlorine bleach is great for sterilizing things and killing mold, but I never use it in laundry washing because of the way it ruins cotton. If you need to bleach your wash to remove organic stains, use sodium percarbonate (oxygen bleach).
  8. Dingy whites: Think of a glass shower door with soap scum on it. And how do you get it off? Acid! All toilet-bowl and tub/shower cleaners are just 10% hydrochloric acid and a thickening agent in a fancy squeeze bottle with a fancy name-brand on it (and a 10,000% markup). You can get the minerals and soap scum out of your clothes, your hair, and your shower with any kind of mild acid. Soap scum is actually a hard plaque made from bonded soap and calcium, and it’s gonna take acid to un-bind them. If you use the correct amount of water softener you shouldn’t have dingy laundry. It’s all a matter of electrical charges at the atomic scale; you have to present one with something else that has a much greater electrical affinity for the one than the other. If you soften your wash water properly, and add a little extra acid, the dingy whites should brighten up nicely. You have to experiment. Or buy an expensive ion-exchange water softener. Also, remember that natural fabric “whites” are not really all that white even when completely new and clean.
  9. “What about brighteners?” We see many commercial laundry detergents that claim to “brighten” whites and even colors. Optical brighteners are actually a collection of nasty chemicals (banned in some countries) that dye the cloth with a fluorescent dye that absorbs ultraviolet light and re-emits it in the visible spectrum. Do you really want your clothes to be fluorescent? Or just plain ol’ clean, without the eye-trickery?
  10. “What’s that nasty residue?” If it’s a gooey residue, it’s soap and excess oils: use more soap and/or soften the water better and/or double-wash and double-rinse (like after you overhaul a greasy engine). Watch the top of your wash water during the agitate cycle—there should not be any greasy goo floating on top. If it’s powdery residue, it’s mineral precipitates: use less Borax or washing soda, or switch to a non-precipitating water softener (citric acid). If it’s a sudsy residue (at the end of rinse), obviously you need to either use less soap, or double-rinse.
  11. “What about fabric softeners?” Cut through all the advertising hype and all “fabric softening” means is removing the minerals from your fabrics, which you can easily do with mildly acidic rinse water. But commercial products go way beyond that—they add a fake smell and some fake lotiony/powdery stuff to make it feel slicker than it actually is. Yuk.
  12. “What about dryer sheets, static cling, etc?” Unnecessary: they brainwash you with the bogus idea that “static cling” is a serious problem you need to worry about. Stray electrons will soon get back to where they belong. If you line-dry your laundry, static cling is nonexistent. If you tumble-dry, after it’s done, put it on air-only (else you’ll burn out the elements!), open the door and hold in the safety switch, then spray in a few shots of plain water with a pump-trigger bottle, and voila! no more static. And no more stinky toxic chemical dryer sheets.
  13. “Is it really clean if it doesn’t smell clean?” More television brainwashing! Cotton should smell like cotton, not lilacs! Good grief! Aren’t there enough real smells in the world already? Do we really need to add some fake smell to everything? It’s like salting all your food: you quit adding salt and in 2-3 weeks you suddenly realize everything has a nice taste of its own. Laundry is only really clean if it has no smell at all, or at the most, the faint and pleasant smell of natural fibers. Why do people want to wash out the dirt, only to replace it with some toxic artificial fragrance? But “springtime freshness” is such a powerful marketing tool that reprograms the brain via the olfactory sense… Example? Most people simply will not purchase any type of cleanser unless it smells like sodium laurel sulfate (SLS)—that’s the smell you smell when you walk down the soap aisle. SLS is TOXIC. And most people will not purchase any body soap or lotion that doesn’t have some flowery fragrance, which, unless it’s actually a natural essential oil (too expensive for commercial products), is a toxic artificial chemical that’s designed to fool the nose (and very cheap to produce in bulk).
  14. “Hot water or cold water?” A hold-over from past centuries when clothes were boiled in a big pot. There is no reason to ever wash in hot water. Consider how many kWh of electricity you waste by washing in 40 gallons of hot water. Kills germs? Okay, so sterilize your wash (if the family is sick) by boiling for 10 minutes! Sorry, but “hot” water from the water heater is usually about 125°F, not nearly hot enough to kill germs. Hot or warm water simply makes chemical reactions (soaps v. fats) occur faster, not better. Use cold water and a little more soap, if needed. And if the wash comes out “dingy” in cold water, adjust your water hardness treatment, not your water temperature. Your mileage may vary, but I haven’t even had the hot water line connected to the washing machine for over 12 years and my laundry still gets clean.
  15. One more. Dryers: I used an electric dryer for 42 years. They work in the rain, they get the job done in 45 minutes, and they shake out the lint and wrinkles. They also consume tons of electricity. But worst of all, they wear your clothes out! All that rubbing and scrubbing and pilling, stitching failing, buttons and buckles and zippers scratching and tearing your fabrics… For the past 12 years I have used only a solar-powered dryer—it’s made of steel and plastic, and it’s 50 feet long. Doesn’t work on rainy days, but I think my clothes and linens are gonna last forever!

Well, that’s about all I can think of right now. I hope you enjoyed reading as much as I enjoy writing. In a future article, we’ll go make a batch of natural laundry soap (and a video), then test it out!

So until then, Happy Soaping! —kv5r

5 thoughts on “Laundry Soap Overview
  1. Thanks for this post. I make my own coconut oil laundry soap and am currently experimenting with citric acid and soda in the washing machine to see how much I need to create a sudsy wash. You noted above that the TDS ppm should be close to 0. I add my soap and then take a measurement. My water has about 100 ppm of TDS. When I add citric acid, the amount goes up. I thought it should go down. What is going on? Thanks

    • You can’t test it after you put the soap in, that changes everything.
      The idea is to do a TDS test first, with plain water, to see how much citric acid you need to soften a washing-machine-full of water. Be sure to agitate between additions and tests and give the citric time to work on the minerals in the water. When your TDS is low, you have the right amount for your water.
      Then from then on you can just add that same amount along with the soap.
      Please let us know how it turns out!
      73, –kv5r

  2. I just found, and read, every single one of your articles on soaping..LOVE, LOVE, LOVE (esp the one on Laundry Soap, but each was an adventure and pleasure)!!!! I make all my own cleaners and most of our personals, but strangely, have never gotten up the nerve to make soap, til recently.. guess I was destine to get the soaper’s itch. I’ve been reading, studying, and taking in everything I can, to ready myself for making some homemade soap (though making all my own liquid soaps is my ultimate goal). Please! Please! Do more!!! Would love to see your follow-up and video on laundry soap too! If you’ve moved to another site, would you kindly disclose the address or link? I very much would enjoy following your projects and writing! Cheers! Patty

    • Hi Patty, glad you like my articles and enjoyed and found useful.
      When you get into making soap, just remember: it’s a chemical reaction; lye will eat your skin; and you need to plan for perfect timing at the trace/pour stage. The rest is easy.
      I haven’t yet made liquid soap, but I understand it’s done with potassium hydroxide (not sodium hydroxide). I do use Dr. Bronner’s liquid soap; it’s really nice and no more than I use it’s cost-effective. Potassium hydrox is quite a bit more than sodium hydrox, so I suggest before you take up making liquid soap, try some Dr. Bronner’s first. A quart bottle is ~$16 at GNC lasts me 1-2 yrs.
      I would love to “do more” but disabled here–the last batch I did with 25% each of coconut, olive, palm, castor was absolutely excellent soap, but I botched the pour and the video, so no viable publication yet. I need a helper!

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