CleaningFilter: Is mixing vinegar and baking soda actually effective?
October 26, 2021 3:47 PM   Subscribe

A popular cleaning solution is to mix vinegar with baking soda. But combining sodium bicarbonate and acetic acid gives carbon dioxide, water and sodium acetate, right? Which of those is going to help clean a surface? Is it the CO2 bubbles we're after here? But how effective are bubbles anyway?
posted by storybored to Home & Garden (14 answers total) 13 users marked this as a favorite
This is a really good question and one I've wondered, too. That prompted me to go looking, and I found this article: "Why are vinegar and baking soda so good for cleaning?"

It's a little shallow, I think, but it seems like a good start. It helped me, anyway, especially the part about not using them in equal parts. Oops.
posted by malthusan at 3:54 PM on October 26, 2021

Response by poster: Good article, malthusan! That suggests the best thing is to use baking soda and vinegar serially which makes sense. Thinking some more about this, the article's point that you shouldn't use equal parts doesn't compute. If you use say x amount of soda, and x/2 vinegar, then the x/2 vinegar gets neutralized and you're left with x/2 soda.
posted by storybored at 3:58 PM on October 26, 2021

I wouldn’t mix those together before cleaning. Vinegar on its own (diluted with water) makes a good cleaning solution, and baking soda on its own (with just enough water to make a paste) makes a good scrubbing solution. After using a baking soda paste, you could follow up with vinegar so the effervescent reaction helps to lift any remaining residue, but that’s probably the only way I’d use both together.
posted by stopgap at 3:58 PM on October 26, 2021 [10 favorites]

I can imagine there being some limited cases where the foaming created by the carbon dioxide helps get the solution into places that it otherwise wouldn't reach (drains for instance?), but yeah, I have been skeptical of the advice to mix these for years.
posted by goingonit at 4:03 PM on October 26, 2021 [1 favorite]

Yep, each one has its uses in cleaning, but once they're mixed they quickly lose the useful attributes of either.
posted by metonym at 4:09 PM on October 26, 2021

Both vinegar and baking soda are effective cleansers on their own. Baking soda is better for things that are greasy, vinegar will get rid of rust, dirt, calcium buildup and soap scum. I use either one to get rid of algae on white vinyl fencing.

Mixing them? This sounds like bad advice given by people who don't actually do anything. Neutralizing the pH removes the acidity/basicity, leaving a salt solution that may clean better than water alone, but is worse than the original components.
posted by sydnius at 4:11 PM on October 26, 2021 [2 favorites]

Response by poster: Bad advice for sure.

Chemistry confirmed: Why you shouldn't mix baking soda and vinegar for cleaning.
posted by storybored at 4:34 PM on October 26, 2021 [2 favorites]

Baking soda is good as a mild abrasive
Vinegar is good for removing lime scale and killing mild microbes
Mixing them is an unhelpful mess
posted by nouvelle-personne at 5:06 PM on October 26, 2021

I have put baking soda in a slow drain and followed with vinegar. It seems to help if there's soap buildup. Otherwise, it seems a sill cleaning formula. Baking soda is mildly abrasive, so can be used for scrubbing. Vinegar is acidic, some people use it to wash windows. I use blue spray. Vinegar seems helpful in the laundry if one forgets to remove clean stuff from the washer promptly and has to run it again. Just because something is trendy does not mean it's effective or accurate.
posted by theora55 at 5:44 PM on October 26, 2021

(drains for instance?)

yes to baking soda and vinegar and boiling water
posted by philip-random at 5:55 PM on October 26, 2021

If you use say x amount of soda, and x/2 vinegar, then the x/2 vinegar gets neutralized and you're left with x/2 soda.

On the one hand, yes, and that's exactly what that article is suggesting, that you want some of one of the two to remain unneutralized/unconsumed, so you get that thing's original cleaning power along with the scrubbing bubbles (TM) of the reaction.

On the other hand, their suggestion of avoiding "equal amounts" is hopelessly vague, because the reaction is 1:1 at the molecular level, not by weight or volume. Sodium bicarbonate has a molecular weight of 84, and acetic acid 60, so if you were dealing with the pure compounds, you'd need 84 g of bicarb to every 60 g acid to get exact neutralization. Add to that the fact that vinegar is usually diluted to 4-6%, and also that being a liquid it is usually measured by volume rather than mass, and the calculation for what amounts will exactly neutralize, while definitely solvable, is complicated enough that I'm not gonna try it on my phone!
posted by solotoro at 6:52 PM on October 26, 2021 [2 favorites]

Heh, the best use for baking soda and vinegar is no-poo hairwashing. The alkaline of the soda (with water) causes bits of the hair to open up to let oil and grime wash away, the acid of the vinegar causes the bits of hair to close back up. Both alkaline and acid have different cleaning properties just when mixed with water. They tend to cover the bases of what gets what off. For a lot of things you can use either one, some things take a bit of both. But yeah wouldn't mix them except to make a volcano (or blow up a plastic bottle).
posted by zengargoyle at 7:58 PM on October 26, 2021

This also frustrates me. I have always assumed that "life hacks" that tell you to combine them were written by people who 1) think that if two things are good for cleaning separately, they must be even better if you mix them, 2) don't know basic chemistry, and 3) have never actually done a rigorous test comparing the effectiveness of this mixture to just vinegar, just baking soda, and salty water.

Vinegar and baking soda show up a lot in alternative lifestyle forums as suggestions for cleaning "without chemicals", which I think contributes to this situation. Hopefully that also means that it's less likely for all these people to own both ammonia and bleach.

I have heard of chasing baking soda with vinegar and closing the plug to unblock a drain, but I have also heard that you should never actually do this because the pressure can crack your pipes instead of unblocking them. There are various lower-pressure suggestions for using them serially which sound more legit.
posted by confluency at 11:44 PM on October 26, 2021 [1 favorite]

When I've seen advice to use them mixed, it's generally been from sources that appear to have no grasp whatsoever of some pretty fundamental chemistry. The thinking never seems to go further than: baking soda is a cheap and effective cleaning agent, vinegar is a cheap and effective cleaning agent, so using both at once has to be better, especially given all that spectacular foaming, right?

posted by flabdablet at 4:04 AM on October 27, 2021 [1 favorite]

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