Wednesday, May 19, 2010

Dishwasher Detergent And Your Dishwasher: A Fascinating Study

Dear Cheapskate,

Do you wish, every time you pour dishwasher detergent into the little indentation in the door of the dishwasher, that you didn't have to shell out for dishwasher detergent? I do.

So I tried some things.

I washed the dishes au naturel, in water only, with no soap. The dishes were still greasy.

I used a substitute: One drop of liquid soap and two tablespoons of baking soda. This worked ok! I would save oodles of money! I'd buy baking soda in bulk and save even more!!

I did some second grade math.
Baking soda in bulk is 89 cents a pound.
Sun (aka "brand X") detergent is $3 for 4.75 pounds at Walgreens, that's 63 cents per pound!! Cheaper, even, than the clever baking soda substitute!!
Safeway brand is $3.49 for 4.68 pounds, or 75 cents per pound.
Cascade is, like, $6 for 4.69 pounds, or over $1.25 per pound - don't even look at the Cascade, not even on sale. You're paying for the advertising.

Conclusion: Sun is the cheapest dishwasher detergent, even cheaper than home-made.

Cheapskate, I know what you're thinking.
Does one use the same amount of baking soda as dishwasher detergent?
Are baking soda and dishwasher detergent the same weight per volume?

I wondered, too.
I washed the dishes using a mere two tablespoons of detergent. The dishes were perfect! (If "perfect" means "mostly clean but you still have to wipe off some crud, as usual".)
I weighed 1/4 cup of baking soda. It was exactly 2 ounces.
I weighed 1/4 cup of dishwasher detergent, expecting it to weigh more, but no, it was also exactly 2 ounces!! The baking soda and dishwasher detergent are the same weight per volume! The diswasher detergent is cheaper than baking soda!!

Tip: Buy brand X dishwashing detergent, preferably on sale.
Tip: Use only two tablespoons (or less) of dishwashing detergent. Do not fill up the whole cup. The box of detergent will last twice as long if you fill the cup only half way!
Tip: Make sure the dishwasher is crammed full before running it. We have a saying in my house, regarding dishes in the dishwasher: "You can always add one more."
Tip: Do not substitute dishwasher detergent for baking soda in your cakes and cookies.

Water, Energy.
Cheapskate, you think too much. You always have just one more question, don't you? Put your hand down - this isn't school; this is a blog. Does the dishwasher use more water than washing dishes by hand? Is saving a few pence on soap cancelled out by the cost of running the dishwasher? Here are the facts (I got this info online so it must be true):
The dishwasher uses less water than washing by hand!!

Here's a great article about dishwasher usage: Does Using a Dishwasher Actually Decrease Water Use?

Whew! Now I don't feel guilty about using the dishwasher!!!


  1. I WillardMay 26, 2010

    Trader Joe's has cheap dishwasher soap. Seems to work just fine.

  2. From my personal tests, I know that in ALMOST all cases, I use much less energy and a little less water when I hand wash dishes than the dishwasher. And this is comparing following all the rules to proper dishwasher usage. My water usage is slightly less than the typical energy star.

    As for energy, the water is never as hot when hand washing as it is in the dishwasher. Add to that the fact that my dishwasher will electrically heat up the water if it is not hot enough (my water heater is set low and is gas), and all the electricity used to run it, and I end up saving with the hand washing.

    Now, when my girlfriend washes the dishes by hand, it is like throwing dollar bills down the drain.

    That being said, on the rare occasion when we have enough dishes to fill up the dishwasher, I will flip the breaker back on and use it. And, there's what may be my biggest gripe with some dishwashers and so many other appliances. Our dishwasher has a phantom load. Enough so that it uses more electricity on the phantom load in a week than if I ran it once a week. We don't generate enough dishes to fill up a dishwasher once a week. On a day to day basis, my dish washing is even cheaper than my experiments. We have well water, so water is free to us (the electric is on the landlord). I don't use hot water to wash the dishes. I use the cold tap, but it takes a while before the really cold water makes it to the sink, instead I am using the room temperature water from the pipes. I can wash a days worth of dishes (not much) before any of the cold water reaches the tap. Room temp water is plenty warm enough. Soap usage is extremely minimal.

    So.... Is a dishwasher cheaper than washing by hand? Usually, but it depends on the washer and depends on your washing style and your situation.

  3. @I Willard: Thanks for the tip! I'll try it.

    @CT Bob: It TOTALLY makes sense that it depends on your your dishwashing chops. And, yeah, what's all the fuss with hot water, anyway???

    My water was off the other day and I managed to get a lot of dishwashing done with just one wet sponge.

  4. I enjoyed reading your blog ~ thanks for posting such useful content.

    Commercial Dishwasher


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