Monday, March 26, 2012

How to Make Washing Soda


**I've made a new post that you can find HERE. The instructions are more clear in my new post and I've included answers to some of the questions I've received over time.**

I've been interested in trying out home made laundry detergent for some time. Funny how it's become a pretty popular thing to do- at least among the bloggers I hang around with. It would be nice to save a few pennies in that area if it all works out like I'm hoping. I've gotten off to a rough start though. First of all, I bought a huge bag of baking soda from Amazon for cheap to use in the detergent. Then I somehow managed to have it shipped to my old home in Utah that we sold! Luckily the new owners knew that the next door neighbors could contact us and my friend there called me and shipped it out to me. I should have just told her to keep it! Without the free shipping the cost tripled because it was really heavy! So, I'm TOTALLY not saving any money with this my first time around. Oh well. Live and learn I guess.

Next I was looking for washing soda. Well, you can't find it in this town. I've looked everywhere! The online prices weren't great. Then I was meandering around the vast internet reading about various detergent recipes and some commenters were asking where you could find washing soda. Another commenter piped up and said you could just heat baking soda in the oven for an hour or so and you'd have washing soda. What?!!! At the time I looked this up- quite a while ago- I couldn't find much else about it. So, I asked my oh-so-helpful husband who just happens to be a chemical engineer. (So handy to have him around!)

This is what we do instead of going on dates- we talk science! ( : We're kinda goofy like that. After much explaining on his part and some grumbling about how I don't "get" anything on my part he finally helped me understand the following:

Baking Soda is Sodium Bicarbonate or NaHCO3

Washing Soda is Sodium Carbonate or Na2Co3

If you heat the baking soda you cause a chemical reaction or in this case you essentially begin its decomposition.  It would look like this:  2NaHCO3 --->Heat---> Na2CO3+H2O+CO2
All of that means that the baking soda you heated changed into 3 new things: sodium carbonate, water and carbon dioxide. The water and carbon dioxide are gases at this temperature so they just float away or evaporate and you are left with the sodium carbonate sitting there.

Sodium Bicarbonate beings to decompose at about 100° C and you'll have complete conversion to Sodium Carbonate at about 200° C. **Edited** I forgot I was in celsius! 200° C is about 400° F. Woops. This is good to know as you'll want to know what temperature to heat it to. Basically, you could heat it at 200° C and eventually all the baking soda would turn into "washing soda." But that could take several hours! So, you can use a much higher heat- say a good 400-450° oven setting. Scratch that part. Basically you'll want to heat your oven to 400° at least- higher than that will make the change happen faster. 

So, here are some pictures documenting my science lesson for today! (I have since found other people writing about this on the internet, but we did figure it out for ourselves, so hopefully I'm not copying anyone.) This is helpful because I've found that many people don't have easy access to washing soda but pretty much everyone can get baking soda- and it's quite cheap!

So, to begin get yerself a big ol' bag of bakin' sody. (Try any large store like Walmart on the pool aisle, or a hardware store or the grocery store.) Now, really, you probably only need a few cups of it depending on the laundry detergent recipe- so even the little boxes of baking soda would work.
 Spread the bakin' sody out on a bakin' dish or cooky sheet.
 Heat yer oven up to 400-475° C.
Stick that there pan o' sody in the oven and let 'er rip!
 After about, say 30 minutes you should see it start to change from this (fluffy, powdery, slightly shiny):
 To this (dull, grainy, not fluffy):
 This here be a side-by-side comparison for you folks (baking sody on the left, washing sody on the right):
I let mine go for a good hour and I stirred it occasion'ly to make for certin' the whole lot of it wuz changed up real good like. Take it outta yer oven and let it cool and yer all set!

OK, OK enough with the goofy talk. I'm feeling a little silly by 11:30 at night after going 100 miles an hour all day! Why am I up sharing this with the world? No idea. (Oh yeah, it might be because there are diapers in the wash and I've gotta stay up until they go in the dryer! Bleh.) So there you have it, and I'm going to bed. Tomorrow I'll hopefully do a post about the laundry detergent I proceeded to make after the washing soda was done.

24 comments:

  1. So funny, I am making laundry detergent today as well! :)

    That is good to know about the washing soda. I actually could find it so I paid quite a bit more for mine than baking soda. Thanks for the tip.

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  2. Chemistry in action! I never thought I'd see the day when anything I (could have) learned in Chemistry actually became applicable in my life. You're amazing!

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  3. Very cool! I've been curious about homemade laundry detergent... I'll be waiting for your next post. (Thanks for doing all the research/hard part for the rest of us!)

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  4. AWESOME! And the best part is understanding the science behind it. I'd love to hang out and hear you and your husband discuss science. :-D

    (I'm pinning this!) What a great tip!

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  5. So I just came here from Pinterest, and I saw your picture on the side, and I think maybe I know you—from junior high or something. In any case, I love your blog, and I'm looking forward to reading it in the future.

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  6. Not only did I learn this tonight, but I also learned that you can get soda bicarbonate at feed stores, in 50-lb bags, for something like $15. Can you say, "I am SO geeked!"?

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  7. THANK YOU! I have had recipes for homemade laundry detergent for years, but never found washing soda. I feel like I shouldn't be so excited about now being able to make my laundry detergent, but I am!!

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  8. How thick can you make the baking soda on a cookie sheet for this to work? Thin or thick, does it matter?

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  9. I don't think it matters how thick. It would probably just take longer to heat through a thick layer and it would be trickier to stir it around on a cookie sheet. If you wanted to do lots maybe do 2 sheets at a time.

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  10. This makes me wonder why you would need to turn it from baking soda into washing soda in the first place. Why would they not be interchangable in a recipe for laundry detergent if the only difference is a little water and carbon dioxide? How would baking soda (instead of washing soda) make the detergent less useful?

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  11. Hello, this is Holly's husband ("The Professor").

    Washing soda (sodium carbonate or Na2CO3) and baking soda (sodium bicarbonate or NaHCO3) have different chemistry. The water and carbon dioxide are reaction products. The carbon dioxide "floats away" because it's a gas. Most of the water sticks around and bonds to the sodium carbonate to help stabilize the washing soda crystals (the washing soda is technically sodium carbonate monohydrate until you disolve it in water).

    While both are useful in detergents, they have different uses because of the different chemistry. The baking soda acts as an odor neutralizer and fabric softener (this is why it is added to some detergents). The washing soda acts as a water softener which prevents hard water agents (such as dissolved calcium) from interfering with the detergent (they prefer the carbonate to the detergent, which wouldn't be the case with the bicarbonate). It also helps remove grease and other tough stains.

    Note that bicarbonate is an "old style" chemical name. It does not mean two carbonates (that would be dicarbonate). The official IUPAC (the international chemist society) systematic name for sodium bicarbonate is sodium hydrogencarbonate, but even chemists (at least in the US) use the old chemical name out of habit and because it's easier to say.

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    1. Thanks professor. I don't know your profession, other than you're a chemical engineer, but I bet you would have been one heck of a chemistry teacher! Chemistry is boring in itself but you probably would have made it fun for everyone.

      This is my first time here and I am definitely signing up for your newsletters Holly. Can't wait to read your future newsletters.

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  12. I've a smaller oven (max-250°C) , how long does it take to work? Thanks.

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  13. Can I make it in a big toaster oven (max-200°C)?

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  14. As I said in the post, I think it takes about 30 minutes to see the change happen. I did this a long time ago and I can't remember how long it took to get my whole pan full changed. Maybe 45 min. max? It sounds like your oven heats high enough, so it shouldn't matter what size your oven is.

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  15. I would think you could do it in a toaster oven just fine as long as it can heat that high. I should try it! I love using the toaster oven.

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    1. Yeah, for small kitchen it's nice and thanks for the reply .

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  16. I've had about 6 cups of Arm and Hammer baking soda spread on a cookie sheet in the oven at 475 degrees for over an hour and it hasn't changed consistency at all! I have an oven thermometer in there as well and it is definitely 475 degrees. I did have the oven set for 400 degrees for the first hour and stirred it a few times, and when I didn't see the change I put it up to 475 for another hour, stirring a few times, and still no change...suggestions??

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  17. Are you sure it wasn't changing? Obviously you posted this hours ago, so I'm probably no help to you now. But the change in the soda isn't terribly obvious. You might compare it side-by-side with some regular baking soda that hasn't been in the oven and see if you can tell a difference.

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  18. Holly, please double check the oven temp in your tutorial -- I believe there is an error.

    I gather you are in the US, so in your caption on the pic of your oven showing the temp, your oven is set to 400-475 F -- NOT 400-475 C as you wrote.

    You could also show both the Celsius and Fahrenheit temps in the caption for the benefit of your international readers -- the equivalent of 400-475 F is 200-250 C.

    Also, for anyone wanting a to make specific weight of washing soda, start with about half again as much baking soda by weight. For example, bake 1500 grams of baking soda to end up with about 1000 grams of washing soda.

    Very nice tutorial!

    ...Another ChE professor...

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    1. That's very helpful, too, thanks. ...And could be the solution to the person above who didn't see the change. Now we can confirm by weight. Science is awesome.

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  19. Well, you are right on one part- I did accidentally put a C instead of an F on the caption of the picture. Thanks for noticing, though to most anyone it should be obvious what I meant.
    But I did put it in Celsius and Farenheit in my explanation near the top.

    "Sodium Bicarbonate beings to decompose at about 100° C and you'll have complete conversion to Sodium Carbonate at about 200° C"

    If I an find the time to edit this post (without a screaming baby on my lap!) I'll probably make this more clear. Thanks!

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  20. I've been making my own washing powder for years but using Borax, found out it's a No No!. I will try your washing soda recipe. Why didn't my chemical engineer son, who attended college until he was 26 because he kept changing his major, tell me this. Love your POST!

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  21. She blinded me with science. :) Good info.Thank you!

    Leslie

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