Homemade dishwasher detergent: are the savings worth the hassle?

A cost comparison of store-bought and homemade powdered dish detergents

Saving Pennies or Dollars is a new semi-regular series on The Simple Dollar, inspired by a great discussion on The Simple Dollar’s Facebook page concerning frugal tactics that might not really save that much money. I’m going to take some of the scenarios described by the readers there and try to break down the numbers to see if the savings is really worth the time invested.

Cheryl said, Making my own powdered dishwasher detergent actually seems more expensive than just buying it at the dollar store.

This was a pretty intriguing comment to me as I’ve made my own liquid laundry soap at a price per load that is about 10% that of Tide. While dishwashing detergent is a bit of a different animal than laundry detergent, I’m interested in how the prices compare.

After scouring the internet for recipes (and trying a few), I found that the best recipe was a very simple one: one part borax, one part washing soda, one part water. This creates a liquid dishwashing soap that seems to clean our dishes pretty well.

As we’ve seen before, I can obtain borax for $2.89 for a box that contains six cups, washing soda for $1.89 for a box that contains six cups, and water is basically free (a tiny fraction of a cent for six cups). If you mix these together, you get 12 cups of dry dishwashing detergent for $4.78 (or 18 cups of liquid), about $0.40 per cup of dry detergent.

I then visited a few different stores in the area and examined their dishwashing detergent prices. I found that the cheapest box I could possibly find in any store was at a dollar store (as Cheryl mentioned), with a box containing approximately four and a half cups of powdered dishwashing detergent for $2. This is a price of about $0.44 per cup of powdered detergent. There were some larger containers of the same detergent, but the price per cup was virtually identical.

I tried out this low-end detergent and found that it did a comparable job to my homemade soap. I would give a slight nod to my soap simply because it managed to get some dried spaghetti sauce off of a pan completely, while the low-end detergent didn’t get all of it. Neither one left significant spots on the glasses or anything and I’d be happy to use either one in my dishwasher.

Simply put, I can save about $0.05 per cup by mixing together borax and washing soda as compared to buying the cheapest powdered dishwashing detergent I could find. Does that make it a bargain? It’s a small bargain in my estimation, but it’s there. This mostly comes about because, by mixing a box of borax and a box of washing soda, you’re making twelve cups of the soap, saving you roughly $0.56.

Now, could we make either item cheaper? It’s certainly possible that dishwashing detergent could be found at an even lower cost than what I found it for. At the same time, it’s certainly possible that I could find borax or washing soda for less than what I found it for. Hitting a sale at just the right time could easily upset the value proposition described here.

Of course, the actual effort involved is also something worth addressing. Mixing together a container (say, an old jug of some sort) with equal amounts of borax and washing soda is pretty simple and if you’re mixing together several cups of each at the same time, you’re saving a little under a nickel per cup of finished product. If you can save just short of sixty cents for a minute or two of effort (which is completely reasonable here), it’s worthwhile.

In my eyes, making your own dishwashing soap is not nearly as strong of a value proposition as making your own powdered laundry soap. There is a bargain to be found here, but making your own powdered dishwashing soap saves pennies, not dollars.

That doesn’t mean I won’t do it, of course. I’ll happily keep using my borax and washing soda mix on my dishes. Sixty cents for two minutes of work is an hourly rate of $18 in pure savings, which isn’t bad at all. Just don’t expect to change your entire world by making your own dishwashing soap.