Zero waste: Homemade laundry soap--Part 2

How homemade laundry soap compares to commercial

My Seventh Generation plastic bottle
sitting atop my bucket of homemade
laundry soap
© L Kathryn Grace

Last week I told you about my grand laundry soap experiment, successful beyond my dreams. I calculated that, in addition to saving on single-use plastic bottles, which may or may not get recycled despite our dropping them into the blue bin, we stand to save 34¢ a load.

How did I get that figure? What does it translate to in $$$ per year? What happens if you factor in fuel and water costs? And what about my time?

We'll take those questions one at a time.

How much does it cost?

I was shocked at the difference in cost per load: 2¢ with my homemade soap, versus 36¢ with my Seventh Generation brand. Here's the breakdown.

Bulk ingredients cost

• Arm and Hammer Super Washing Soda, 55-oz box at $4.29 / 14 batches* (1/2 cup or 4 oz. per batch) = 31¢/batch
• 20 Mule Team Borax, 76-oz box at $5.99 / 19 batches* (1/2 cup or 4 oz. per batch) = 32¢/batch
• Fels Naptha Bar, 5.5-oz at $1.99 / 3 batches = 66¢/batch
• Total materials cost per batch: $1.29

*Batches are rounded to nearest whole.

Cost per load

Cost per load

Seventh Gen: 36 cents
Homemade:  2 cents

Each batch yields two gallons laundry soap. At 1/2 cup per load, we get 64 loads per batch. Cost per load: $1.29 / 64 = 2¢. Two cents per load!

How does it stack up?

The Seventh Generation Natural 2X Concentrated Laundry Detergent bottle claims 66 loads. At $15.99/bottle, cost per load is 24¢. Read the fine print, and it turns out that you get 66 small loads. For the large, full-capacity loads I do, Seventh Gen recommends about half again as much detergent, which means I only get about 44 loads per bottle. That raises my per load cost to 36¢.

By making my own soap, I save 34¢ per load. On average, we wash about 10 loads per week. That's 520 loads per year and a savings of $176.80 a year on laundry detergent. Add that to the $150 I calculated in May 2010, that I would save on paper towels, and in a few years, I may have squirreled away enough to get the super thin, lightweight MacPro I covet. Okay, that's a stretch, but if I keep finding ways to save, it could happen.

What about fuel, water consumption and labor factors?

If I'm to live a more sustainable lifestyle, I need to think of the hidden costs of fuel, water and labor, right? Here's the skinny.

Fuel and water--A wash? Probably much less

The fuel cost is negligible. While I have not calculated the cost of the gas to heat the water, I can tell you my gas bill did not change noticeably the month I made the soap, and I did a lot of holiday cooking and baking that month.

Fuel cost to transport the bulk ingredients? Again, negligible compared to the fuel cost to transport a single-use bottle of the commercial detergent. How do I know this? Because the bottle washes fewer loads than just one batch of my homemade soap, whereas the boxes of washing soda and Borax, along with the bar of Fels Naptha, will give me multiple buckets of homemade, and the three products weigh little more than the single commercial jug.

Then there's the water. Because my rent includes water, I don't have anything to compare my water usage costs. The two gallons of water I use, plus any water I used in cleaning the pot and utensils, which I washed with other dishes, are worth pennies in today's economy. That may not always be true, of course.

I couldn't find easy stats on the laundry detergent polycarbonate bottles, but I did learn that it takes about forty percent more energy to make the polycarbonate detergent jug than a litre of bottled water, and it takes a lot of fuel to manufacture and deliver that one liter of bottled water in a typical PET plastic bottle.

On the surface it appears that I use far less water and energy to make my homemade soap.

Labor costs

As for my time, it took about half an hour to make the soap. It was as pretty to make as lemon curd, smelled lovely, and was a delight to see in its bucket when it was mixed. Forgive me, but I see that as a pleasant gain--time well spent.

Still, let's see how the numbers play. Say my time is worth $40/hour. How would the cost of making homemade laundry soap change?

$40/hour * .5 hours = $20
Ingredients = $1.29 (see above, "Bulk ingredients cost")
Total cost per batch: $21.29

Annual cost, based on 8 batches/year = $170.32
Annual cost of Seventh Generation detergent, based on 36¢/load (see above) = $187.20
Annual cost of Seventh Generation, $187.20, less annual cost homemade, $170.32 = $16.88 saved

So even if we factor in my labor, I've saved $16.88/year. Put another way, divide that $16.88 by the four hours labor I will spend in a year, and I just earned $4.22/hour. That raises my "pay" to $44.22/hour! I like that.

AND! And, I don't have to buy a plastic laundry detergent bottle ever again.

But it's messy!

Of course, there's the fact that the homemade soap is slightly more difficult to use. We have to stir the batch each time we use it, and it's a bit messier to measure the goo. Those plastic bottles, with their dripless pour spouts and their easy-to-use cups beat measuring and pouring out a half cup.

Love that feel-good moment

Each time I open the bucket, I take pleasure. The color, the scent, and the fact I made it myself all contribute to that good feeling, canceling the slight hassle that costs me maybe thirty seconds, including the time to rinse the spoon and measuring cup.

I love that I don't sneeze or get headaches on laundry day, and I love the sense of satisfaction I feel at having found a way to refuse bringing one more plastic container into my home.

Reducing the risk of harm to children and workers overseas

I was unsuccessful discovering where San Francisco's recycled plastics go. I am glad to know that my love of convenience and clean clothing is not putting laborers, including small children, at risk as Britain's plastics did for some time in this Chinese factory. That one got enough bad press that they closed it down. No one seems to be talking about where our plastic bottles and jugs are recycled now, but it is difficult to imagine, with so little transparency, that worker conditions are any safer today.

Knowing I've stopped one small contribution to such suffering is worth the tiny bits of trouble it takes to make and measure the soap, long before I factor in the cost savings, don't you think?

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We make peace in a million small ways every day.

All text and images, unless otherwise noted, copyright L. Kathryn Grace. All rights reserved.