Tuesday, January 24, 2012

Homemade Laundry Soap Research

Last weekend, I made homemade laundry soap.  I've heard this should only take about 15 minutes to do, but I took at least an hour because midway through I started second guessing which recipe to follow and took a good 45 minute break to research everything.  Again.

There's an overabundance of recipes for homemade laundry soap floating around on the internet.  This website alone has collected 10, and I think the comments include a few more variations. There's a lot of information and a lot of people contradicting each other which it comes to homemade products. (Differing opinions on the internet?!  Who knew?!)  The most helpful sources seem to be the mothers laundering baby diapers.  Not only do they have a need to get some serious junk off what they are washing, it needs to be gentle enough for a baby's skin. 

Why use homemade laundry detergent?  Lots of reasons.  It's frugal (generally $.01/load).  A simple batch generally yields a generous quantity, so there's less frequent making/purchasing.  It's virtually zero-ish waste because containers get reused- think about how many plastic detergent containers you've bought and thrown away.  They may get recycled, but you're still creating demand for them to be made.  There's also far fewer fragrances and dyes to irritate skin- unless you want a particular scent, why have them in there?  Plus, your skills will be in high demand when the zombie apocalypse comes.  It seems to work as well as regular store bought detergent (one example here), so why not?

Well, for one, the effectiveness of your personal soap seems to involve a bit of trial and error and some basic chemistry.  I've been several months off and on researching this before I finally made a batch.  It was confusing.  If you're thinking about making your own, here's a few things to consider.

First: Hard water vs. soft water
It's important that you know whether your water is hard or soft.  If you don't know off the top of your head, go look at your shower head or glass shower door.  If you have limescale deposits (whitish powdery stuff and rather hard to clean off shower doors), you have hard water.  If your soaps lather up really easily but doesn't wash off super easily, you probably have soft water.  There is a regional factor to this: New England, the Northwest, and Gulf coast tend to have soft water.  The Plains and Southwest tend to have hard water.  HOWEVER, about 85% of tap water is considered hard.  If you are confused as I am about your water (but have more disposable income), a hardware store should have a test kit that will tell you how hard your water is.  If you don't want to spend that money but like tea, use this home test.  If you don't like tea, use this test.  The advantage of a test you have to pay for is that you'll find how how hard your water is on a hard water scale (soft, slightly hard, moderately hard, hard, very hard) which depends on how many parts of hardness per gallon you have.  To confuse things even more, previous owners/landlord/etc may have had a water softener hooked up so even if your neighbor has the hardest water ever, you may not.  Ok, now that you know (or know that you don't know!) what the water is like in your home, read on.

Second: Soap vs. Detergent
This is a summary of this article by Heather L. Sanders plus other relavent information I found.

What is the role of soap/detergent in laundry?  As a surfactant (surface active agent), it helps reduce the surface tension of water.  If you walk outside in the rain wearing a raincoat, the rain is probably going to bead up on the outside of the coat.  The surface tension of the water droplet is what allows the droplet to retain it's shape.  Surfactants cut that surface tension so it can soak into the clothes.  Both soap and detergents are surfactants.  Soaps are generally made from natural materials (oils/fats) and detergents are made from synthetic materials (chemical equivalents).  Detergents tend to work better in hard water than soap.  Soaps form a scum that doesn't wash away as easily in hard water. Detergents have been prevalent since WWII because it takes out the trial and error factor of homemade laundry soap- they will work in hard water, no fiddling with a recipe or additives. 

Third: Composition of a Homemade Laundry Soap
There are many variations of proportions and occasionally some other ingredients, but here's what the most common ones do.

1.) soap - surfactant (see above), see #4 for which soaps to use

2.) borax - sodium borate, a whitener and deodorizer.  It raises the ph of the wash water to a basic solution, softens hard water by removing hard water minerals, and is a color safe bleach alternative. This can be found on your laundry detergent aisle as made by 20 Mule Team or online.   

3.) washing soda - soda ash, helps remove dirt and odors. This is NOT baking soda.  Baking soda is sodium bicarbonate. Washing soda is sodium carbonate (and can be derived from baking soda when heated, google for instructions).  This can also be found on the laundry detergent aisle as made by Arm and Hammer.  If you don't have luck there, try the pool aisle/store and look for soda ash (just make sure it's pure sodium carbonate) or online.

4.) essential oils - Since many homemade laundry soap recipes leave the clothes coming out smelling like nothing (i.e. no "fresh clean smell"), some people like to add essential oils. 

5.) vinegar - ok, this is not actually added to the recipe (usually), but is often suggested to add to the rinse cycle or fabric softener dispenser.  White vinegar helps strip excess soap/detergent out of the water and lowers the pH of the water.  If you line dry you clothes (like me), it's rather important to have a fabric softener so everything doesn't dry to a stiff board.  I dilute mine in water before adding it to the dispenser.  Oh, and bonus: it's safe for microfiber (most fabric softeners are not, check your care instructions).

Fourth: Which Soaps
Most recipes suggest Fels Naptha Soap (found on the laundry detergent aisle), Zote (I've heard Mexican stores and Dollar Generals if not in your grocery store), Castile, or Ivory. 

Fels Naptha -  a pure soap specifically formulated for pretreating stains and removing residue from poison oak/ivy, etc when washing
Zote - made from coconut oil and tallows and contains an optical brightener and citronella. 
Castile Soap (Kirks, Dr. Bonners**, etc) - made from olive oil instead of tallow
Ivory - made from similar ingredients as Fels Naptha (based on skimming their listed ingredients), but with the purpose of body soap, not laundry soap
homemade soaps- there have been universally positive results from people making their own homemade soaps who then use those soaps in laundry soap.

There is much anecdotal evidence (read: multiple commenters on every homemade laundry soap post) that whatever you use in your shower and the mini bars from hotels will work too.  I caution against that.  It may contain fragrances or oils that could leave stains on your clothes or react with the other ingredients in a negative way.  That said, if one has allergies/sensitivities to anything in the soaps listed above, start with a soap you know won't react with your skin.  Just make small batches and test on non-expensive, easily ruined items.  If you don't have skin sensitivities and just want to make a batch already, start with whatever soap on the list above you can find easiest. 

Fifth: Which recipe
I can't suggest a recipe because I haven't experimented enough to figure out what works best with my water.  I can say that based your water type, you'll have better luck increasing or decreasing certain ingredients.  In general, most combinations should work because the soap is decreasing surface tension, the borax is whitening and deodorizing, and the washing soda is helping remove dirt/odors.  However...

... if you have hard water, you may want to increase how much borax you use.
... if you have extremely hard water, you may want to even double the amount of borax you use. 
... if things aren't getting clean enough (dingy white shirts, etc), try
      ... adding white vinegar to the rinse cycle as a fabric softener or more borax per load
      ... Zote contains an optical brightener (which many conventional detergents contain)(I have no personal experience with this)
      ... add bluing
      ... add lemon (citric acid has whitening properties) 

Sixth: What container
There are powdered soap recipes and liquid soap recipes.  The main complaint against liquid recipes is that they take up more room.  You can store them in old, cleaned pour spout detergent containers, milk jugs, or buckets.  For free buckets, ask the bakery section of the grocery store if they have any extra icing buckets they want to get rid of (bonus: there's about 1/2c of white frosting left in the bucket!).  For powdered soap recipes, plastic containers (yogurt, glad, ziplock, tupperware, etc) work well. 

Seventh: HE machines?
Does this work in HE machines?  I have a top loading HE machine (yes, they do make those!) and I don't want to break it.  I can't find a satisfactory answer to this.  The soaps listed above are low sudsing, which is good for HE machines (using a non-HE detergent in an HE machine can cause it to foam over).  Anecdotal evidence (read: commenters on blogs) say it works great in their machines! However, I did find one commenter (among hundreds that I've read I might add), who suggested this:
This formula is missing the corrosion inhibitors, enzymes and chelating agents that are usually present in a commercial detergent. This may reduce the life of your clothing and washing machine. I would caution against using this in a HE or front loading washer. Because the water use is lower, concentrations of contaminants is higher and these additional ingredients in commercial products are more critical. Also, there are typically special surfactants or surfactant formulations that do not foam as much to prevent damage to the machine.  ~ Credit
Now, his last point about surfactants I feel isn't well founded because Fels Naptha IS low sudsing to the point that many people who start use it get worried that there aren't enough suds.  However, that first part?  I'm not sure. I've tried searching for answers, but it's a bit beyond my understanding of chemistry. 

Eighth: My Unanswered Questions
So, I've learned a lot, but I still have questions.

1.) Does my laundry detergent need the corrosion inhibitors, enzymes, and chelating agents found in commercial detergents to prolong the life of the machine?

2.) Borax raises the pH of the water to a basic solution.  Vinegar lowers the pH to an acidic solution.  If you mix them, you can make salt.  Can I use a homemade laundry soap that contains borax (or use it as a booster to commercial detergent) and still add vinegar to my rinse cycle without making salt?

3.) Would homemade recipes please indicate whether they mean 2 cups of grated soap or 2 cups soap, grated??  They are different!  I grated 4.5 oz of soap and yielded 2 cups grated soap. 

4.) What is the specific hardness of these recipe posters (specifically on the scale of water hardness)?  It's well and good to say "I have hard water and this works great!" but what level of hard water?  What if I don't have hard water?

I've only used my recipe once so far, which is not nearly enough times to recommend it.  If I like it, I may post what works for me.  I have a feeling it will take a while for me to feel comfortable endorsing any particular recipe.

** after I wrote and posted this, I looked at Dr. Bonner's Castile soap in the grocery store.  While it likely does have olive oil in it, there was more coconut oil.

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