Actual Savings: Homemade laundry detergent

Work on the patio has commenced, but due to a combination of weather delays and protesting muscles, we weren't able to complete Phase Three (Excavation) today. So I'll wait to fill you in on that job when it's done, and instead give you an update on a much longer-term project that was just completed today: tracking our laundry detergent use.

As you may recall, way back in January I made a note of the date on a newly opened bottle of detergent. This idea was inspired by the frequent posts I kept coming across on frugality websites (such as this one at The Simple Dollar) about the benefits of making your own laundry detergent. I was skeptical about this, because it didn't seem to me that laundry detergent could possibly be a big enough expense for us to make it worth the trouble of mixing up our own. But I figured I couldn't be sure exactly how much we pay for detergent in a year without tracking the amount of time it takes us to go through a bottle. And as of today, I have the answer: exactly 24 weeks.

Now, admittedly, this is actually a much shorter period than I was expecting. There are several possible reasons why I might have "misunderestimated" our detergent use, as our former president would say. Perhaps we actually do more loads of laundry per week, on average, than the 1.5 I estimated in my initial post. Or perhaps I actually use more detergent in each load than the one-third to one-half a capful I thought I was using. Or perhaps the detergent manufacturer is actually exaggerating when they claim that a 50-ounce bottle is enough to wash 32 loads, using a full capful each time. Or maybe it's a combination of all three.

However, it turns out that while my estimate of how long each bottle lasts us was low, my estimate of how much each bottle costs us was high. I said that we "usually find it on sale at about $2 for a 50-ounce bottle," and that's true—but detergent is also one of the few items for which we consistently manage to stack sales with coupons. So not only can we usually find a brand of detergent we like (basically, any brand that's unscented) for $2.00 a bottle, but we can usually combine that sale with a $1-off coupon, or a 50-cents-off coupon that doubles. So our actual cost is only $1.00 per bottle. And at that price, even if we go through a bottle every 24 weeks, our total detergent cost for the year is only $2.17.

Now let's compare this with the results achieved by Trent, the blogger at The Simple Dollar, when he tried mixing his own laundry detergent. He spent a total of $6.97 on the ingredients (factoring in water and fuel costs). He estimates that these ingredients are enough for "at least six batches," each of which will wash 52 loads of laundry, making his cost per load around 2.2 cents. Now, if my initial estimate of 1.5 loads of laundry per week is accurate for our household, then our one-dollar bottle of detergent washes 36 loads of laundry, making our cost per load about 2.8 cents. So switching from sale-priced detergent to homemade could, in theory, save us 0.6 cents per load—which works out to about 47 cents a year. That's pretty far off from Trent's estimated savings of $65.08 a year.

In reality, though, our savings is probably even less than that. As I noted above, it's likely that we are actually doing more than 1.5 loads of laundry per week, because we went through the bottle of detergent much faster than we should have if that were the case. So assuming conservatively that we actually do around two loads per week, our one-dollar bottle of detergent is actually getting us through 48 loads, at a cost of just under 2.1 cents per load. In other words, we're actually paying slightly less for our sale-priced detergent than Trent is paying for his homemade stuff.

Moreover, even if we could save a whole 47 cents a year by making homemade detergent, we'd have to go through the process of mixing up a batch every six months. Trent's recipe calls for grating up a bar of soap by hand, then stirring it bit by bit into a pot of simmering water, and pouring the whole mess into a big bucket along with three gallons of warm water, a cup of washing soda, and half a cup of Borax. This whole process couldn't possibly take less than fifteen minutes, counting the time needed to wash the pot out afterwards. So we'd be spending half an hour per year making detergent in order to save 47 cents, earning a princely wage of 94 cents an hour for our efforts. Moreover, we'd be washing our clothes with what Trent describes as "some slimy-feeling water with various sized pieces of white gelatinous stuff floating in it," which has to be dipped up by the cupful out of a five-gallon bucket (which we'd have to find room to store somewhere in our laundry room). Am I the only one who has better things to do with my time?

The moral of this story, I think, is that advice on saving money should always be taken with a healthy dose of salt. People who write articles for save-money newsletters and blogs know they aren't going to excite anyone by claiming that an idea can save you a few dollars per year, so they are liable to make the most generous estimates possible in order to maximize their claims about how much you can save. Trent, for instance, came up with his estimate that his homemade laundry detergent would save $65.08 per year based on the assumption that you are doing one load of laundry per day—and that if you weren't using his homemade mix, you'd be using Tide with Bleach to the tune of 20 cents per load. For us, both these assumptions were way off base. So whenever you see a claim like this, it's worth taking a minute to think it through, and maybe even crunch some numbers, to see whether the claim is reasonable, bogus, or somewhere in between.