Everything You Need to Know (and More!) About Doing Laundry with Rainwater

And exploration of laundry with rainwater, by guest blogger  Linda Holliday

Economy of using rainwater in the laundry room

Whether our goal is to save money or the environment, most of us detest wasting anything. Many folks may not realize, however, how much soap is squandered in the laundry room when washing clothes in hard water — rather than naturally soft rainwater.

These jeans will stand by themselves after being washed in hard water!

As most homesteaders rely on water pumped from far below ground to fill their washing machines, and hard water is prevalent in vast regions of the United States, soap-wasting is widespread. I hail from the Missouri Ozarks atop a karst (limestone) terrain. Our water is exceedingly hard, meaning it contains a considerable quantity of dissolved minerals, mainly calcium and magnesium. Iron and manganese are also often present in hard water.

Those minerals, while safe to drink, make soap less effective, smearing into a grayish cream with no lather. Because soap does not dissolve in hard water, much of it will remain in the materials being washed, leave scum in the wash basin, or simply go down the drain. Here, jeans laundered in well water can stand on their own after line-drying on a breezeless day.

Hard water can even shorten the life of fabrics. Over time, this buildup of soap makes clothing grimy, drab and discolored. Sadly, pretty garments often end up in the rag bin far sooner than necessary.

Municipal water, in most cases, also comes from drilled wells or reservoirs of hard water that is then chemically treated to reduce hardness.


Laundry with Rainwater

Hard Water Map

U.S. Geological Survey Hard Water Map.  General guidelines: 0 to 60 mg/L (milligrams per liter) is soft; 61 to 120 mg/L is moderately hard; 121 to 180 mg/L is hard; and more than 180 mg/L is very hard.

Rainwater, on the other hand, contains concentrations of sodium and potassium ions that dissolve soap and lift soil. Just a few generations ago, folks would bathe and wash clothes in rainwater with no soap whatsoever. Great-grandma knew the cleaning properties of rainwater and always saved enough to wash her hair.

In the 1906 classic, “The Jungle” by Upton Sinclair, protagonist Jurgis Rudkus finally eliminated months of slaughterhouse and fertilizer plant grime from himself by scrubbing his body and clothes with sand in a stream. Hard Chicago water couldn’t get the poor fellow clean.

In many countries it is common to see families bathing and doing laundry in local rivers and streams.


Soap vs. detergent

We often use the terms, “soap” and “detergent” to mean the same thing, but there is a vast difference. Soap is basically made of an alkali (historically plant ashes) and a fat or oil (animal or vegetable). By itself, the alkali substance is corrosive and injurious to cloth and skin. Combined with fats in soft water, it is safe to use on skin and fabric. Detergents, as explained below, are manufactured with petrochemicals and/or oleochemicals.

The original reference “The Laundry Manual; or Washing Made Easy” of 1863 states, recommends soaking heavily soiled clothing and linens overnight to loosen dirt before washing, thereby reducing wear to fabrics by vigorous rubbing and scrubbing. Rainwater, of course, is best for presoaking.

“Soft water is of itself a good solvent, even of the oily materials that collect upon the linen worn in contact with the body,” the book states.

For years, I have collected such books as I have found them to be the source of much wisdom. For those who prefer learning in an electronic format, Open Library.org has thousands of old-time books in the public domain to download for free. Search for household cleaning or laundry work for information on rainwater uses. Remember, these books were written when every home had a rain barrel beneath the downspout.

Besides relearning old-fashioned skills in my antique books, occasionally I am amused and more appreciative of living in modern times. Consider this bit of housework advice at the onset of the Civil War:

“We have found by experience that the use of the above recipe [presoaking and then boiling laundry] is the best friend to the washer-woman ever invented. By it one person can do the washing for a family of ten or fifteen persons before breakfast, have the clothes out to dry, and the house kept in good order, and the gentlemen of the family, as well as all about the house, free from washing-day annoyances, and all without rubbing or machinery. Who would not wish to have such comforts?”

I suspect there are not many 15-person households in the United States these days, and of course the “gentlemen” are doing plenty of laundry themselves!


Potions needed for hard-water laundry

When animal and vegetable fats and oils became scarce during World Wars I and II (as they were needed for making bombs), scientists developed petroleum-based detergents to replace soap and make cleaning more effective in hard water, according to the American Cleaning Institute. At that time, petroleum was found to be a plentiful source for manufacturing detergents.

Today, there are a host of chemical laundry aids available to contribute to the effectiveness of detergents, particularly in hard water:

Bleaches – to whiten and brighten fabrics

Bluing –to counteract natural yellowing of fabric

Boosters – used with detergent to enhance stain removal

Enzyme presoaks – to remove stains and boost a detergent’s cleaning power

Fabric softeners – added to the final rinse to make fabrics soft and fluffy, decrease static cling, wrinkling, and drying time, to impart a pleasant smell and make ironing easier

Prewash soil and stain removers – to pretreat heavily soiled or stained garments

Starches, fabric finishes and sizing – used in the final rinse or after drying to give body to fabrics, make them more soil-resistant and make ironing easier

Water softeners – added to the wash or rinse cycle to inactivate hard water minerals and increase cleaning power.


Rainwater laundry methods

Amish Wringer Laundry

Open-top wringer washing machines can still be found at farm auctions and are easy to fill with rainwater.

While making your clothing smell like a springtime meadow, such supplements add more time and expense to laundry day – and are completely unnecessary if doing laundry with rainwater and natural soap. Incidentally, one needn’t have a washtub to clean clothes in rainwater. If a washing machine is in a basement, a hose can be routed from the rain barrel to gravity-feed water to the machine. A valve at the discharge end makes filling the machine easier, although it must be monitored to prevent overflow.

Or, for the more physically ambitious, the machine can be filled more quickly by bucket. Depending on load size, the wash and rinse cycle each require about 15 gallons of water. Wringer washing machines from the 1950s work especially well like this.


Testing water for hardness

Generally, it is obvious by the rigidity of line-dried garments and by scum or scale left on tubs, sinks and toilets whether the household’s water is hard or soft. For a quantified result, inexpensive water test kits are available in hardware stores. Also, many county health departments will test well water for impurities and hardness for a small fee.

Hard Water Test

The glass on the left is filled with rainwater, clearing dissolving soap and forming suds. The soap did not dissolve in the glass on the right, filled with hard water.

For the do-it-yourselfer, “Household Discoveries” of 1909 explains an easy way to discern if your water is fit for laundry purposes. Simply dissolve a dab of good white soap (not detergent) in a tablespoon of rubbing alcohol. Put a few drops of this in a glass of water. “If the water is pure, the soap solution will be dissolved and the water will continue limpid, but if it is impure the soap will form into white flakes which will tend to float on the surface.” Results will be readily apparent.

For comparison, I filled two glasses of water – one from our drilled well and the other from the rain barrel. I mashed up a small chunk of my favorite homemade goat milk soap in rubbing alcohol and put equal drops in both glasses. The soap disappeared immediately in the rainwater, but never dissolved or formed suds in the well water. After an hour, the well water glass had a scummy ring on top. The rainwater glass never did – even after sitting overnight.


Softening hard water naturally

“Household Discoveries” lists numerous ways to soften hard water, such as by boiling with baking soda or wood ashes tied in a woolen bag or adding chalk, potash, borax, soda lye or quicklime and then incorporating air by repeatedly pouring the modified water from one container at some height to a tub at length.

All of the above water-softening steps and aforementioned chemical cleaning agents can be avoided by simply collecting and using rainwater. As an added plus, doing laundry with rainwater will also save money – and the environment.


About Linda Holliday

Linda Holliday lives in the Missouri Ozarks where she and her husband formed Well WaterBoy Products, LLC, a company that designs and builds devices – including the WaterBuck Pump – to help people live more self-sufficiently, especially regarding water. Linda is a Mother Earth News blogger, former newspaper editor and reporter and has been featured in national publications such as “Grit” and “Farm Show Magazine.”