Kimwipes and buffer solutions and nitrile gloves oh my!

(Technically, the water was courtesy of my long-suffering and non-judgemental spouse, but you get the idea. Also, no bird in a fruit tree; I'd have nowhere to put it.)

In This Post:

My pH kit haul

Prepping my gadgets

Test results

Lots of science blather about Vitamin C, BHA, and AHA

Whether it's worth going to all this effort

What's worth buying & where to get it

Just as a quick reminder: this blog uses both affiliate and non-affiliate links, and if you choose to click the former before you shop, your purchase may contribute a tiny amount to the maintenance of this blog. See full details at the end of this post! #receipts

pH strip result for my tap water. Is it pH 7? 7.25? 7.5? Who knows?? (Spoiler: my water is actually 7.55)

My pH kit haul

Tiny screwdriver NOT included!

Prepping my gadgets

breaking and tinkering

Test results









This was interesting, because I had previously pH strip estimated a 4.25-4.5 range, so I was relieved to see that my estimate was accurate. As I mentioned above, that's low enough for AHA but too high for BHA. Either way, the concentration in this toner is too low for use as a deliberate chemical exfoliation, but that's not what it's used for.





It's great as a pH adjuster for the skin; when using pH dependent products your skin needs to be at a natural/low pH before use, so you can either let your skin self-adjust after cleansing by waiting 15 minutes, or you can force the pH down with a product if you are rushed/live in a dry climate. This toner is excellent at the latter. That's how I use it, as well as cleaning off the post-acid-exfoliation sludge of dissolved dead skin and sebum before applying the rest of my products.









Cosrx BHA Blackhead Power Liquid results: 3.37

















My pH strip estimation for this one was 4, so still close but I'm relieved to see it's in the 3.5-4 range. However, since it is over 3.5, I don't layer it over my BHA to avoid disrupting the pH zone it's working in (which is best below 3.5) and wait 20 min after BHA before applying my AHA serum. I then wait another 20 min to let the AHA do its thing, and then carry on with the rest of my products.





Whether it's worth going to all this effort

Will I break this out to test every new product? Honestly no, because it's a pain in the ass and requires recalibration each time you take it out of storage; it's stored with solution in the cap (pictured in the image with the screwdriver) to keep the probe from drying off, but it still needs to be rechecked for accuracy (and adjusted if need be) before use. That means keeping plenty of the buffering solution on hand as well.





The results showed me that my pH strips + eyeball estimates are close enough for non-pH dependent products like serums, essences, cleansers, etc. So for 80% of my products, the strips are fine.





However, if I am testing pH dependent products that have specific pH requirements, I will definitely break out this kit and get all Mad Scientist in my kitchen.

What's worth buying & where to get it

Since the strips will get you close enough for everyday use, they're the best way to go. Cheap, readily available, and simple to use. You can even stash them in your bag for quick testing in-store if you're on a shopping trip. Avoid the single-indicator strips. They're less precise, so I get this type instead:





Multiple indicators for the win!

I've used and liked:





MN brand 0-14 pH strips: Amazon | eBay





ColorpHast brand 0-14 pH strips: Amazon | eBay









All the best,

-Cat





**Disclaimer: All products I review on my blog are 100% purchased with my own money, with a single exception of a press sample I tested & reviewed in 2015 which swore me off of them forever. Personal gifts from friends & family will also be identified. This blog contains both affiliate and non-affiliate links, and clicking the former before you shop means that this blog may receive a small commission to assist in this blog supporting itself. Please see my Contact Info & Disclaimer policy for more information.

Unboxing posts are popular in the blogging world, but today's contents are a little different than what normally gets delivered to my door.On the 12th day of Christmas, my mailman gave to me: A gallon of distilled water, 280 Kimwipes, 100 nitrile glooooooooooooves, 4 buffering solutions, 100 pH strips, one digital pH meter, and a partridge in a pear tree.Over the last year, my interest in beauty products has shifted; I am as enamoured of Asian beauty products as ever, but now I'm highly curious about theof skincare.If you've been following my blog, you may have noticed that I have started looking deeper into the ingredients of my products, especially those that are considered 'actives' and therefore expected to have reliable results, and doing a lot of research on the science of skin and skincare, such as mypost, where I get granular aboutHowever, doing science-at-home isn't easy, and some of the questions I get are how to test your products effectively at home, which pH strips to use, and how to test the pH of lipids (oils, fats, etc). The problem is, pH testing works via measuring an aqueous (i.e. water-based) solution.: you can't at-home test oils, although pH testing oils is a part of fuel manufacturing. That being said, unless you are planning on refining diesel in your basement (in which case, I don't want to know) at-home oil testing is off the table with current methods.One of the easiest and cheapest ways to pH test your products is with pH strips, and for most products, these work great. I used to have thewhich you tear off a piece as you need to, and then compare it to a series of whole number and then. I find theis easiest to be accurate with, although you still have toIt's not such a big deal when it comes to things like face creams and cleansers, where you have a wide range of acceptable pH goals (see the above Skincare Discovery post link for details) but when you are dealing with pH-dependent ingredients such as acids (LAA, BHA, AHA, PHA, etc) a 0.2 difference can make or break its function as an exfoliant. At least, that's what my research has lead me to believe.Precision is less of an issue if you have something like an AHA, which is tolerant of a pH of 3-4.5 (above 4.5, you are going to lose the efficacy of exfoliation, although you may still get other benefits) so if your pH strip result looks like it's approximately pH 4, you should be fine. Maybe it's really pH 3.75 or 4.25, but 'approximately 4' is within the acceptable range.When you get a BHA, however, that range narrows to below 4.2, so 'approximately 4' could potentially be too high. LAA (one of the popular Vitamin C serum sources) is even more sensitive, requiring a pH of less than 3.5. [So while chatting with a(aka a lady who knows her way around) and learning about limitations of pH strips when testing acids, I decided to purchase a digital pH meter at her recommendation.The first one I bought was a bust, asthat had to be immersed in the liquid until the electrode was covered. This is fine for dunking into an aquarium, swimming pool, or any other large body of fluid. Testing a $60 face serum, where every drop is precious? Uh, no. I'm not willing to sacrifice a third of a bottle or jar of a product for testing purposes.So I went looking for other options and decided onwhich I could dip into a narrow container and thus use only a tiny amount of product and still get the level high enough to cover the electrode.This meter is a 2 point manual calibration, which means that you have to purchase 2 specific buffering/calibration solutions (pictured at the top of this post), one of which is 'neutral' (usually 7.01) and one that is either low (4.01) or high (10.1) for the 2nd calibration point.These solutions are tricky/expensive to buy online, so I had to go old school and call around to my local fish supply stores. After a very talking to an increasingly mystified employee there, they ordered me in the pH solutions I needed, which were less than $2 ea so I had them get me a, andI am not sure what he thought I was up to, but he finally asked me flat-out what I was using it for, and when I explained it was to pH test my skincare for my blog, he became strangely excited which makes me think that he was either encouraged that girls are nerds too, relieved that I wasn't trying to cook up some sort of Fight-Club-Soap operation, or that he's just really into pH testing? At said scientist's recommendation, I also picked up someand powder-free, and some distilled water for rinsing as I test. Safety first, you know!The meter did not come with a screwdriver to adjust the Calibration screws at the top, but luckily my husband had one in his stash of electronicsrepair stuff.I had assembled all my gear and was excited to start, when I read the instructions (pictured at left) which requires it to bebefore initial calibration.Cue extreme disappointment.to create the narrow container I needed, and scrambled around in my kitchen until I found a wineglass (DON'T JUDGE ME, it was all I had, ok?!) that dipped down into the stem and gave me the narrow-but-deep shape I needed. Per the instructions, I poured some of the pH 7.01 solution into the glass and soaked probe for a few hours. The calibration instructions, including how to complete the 2 point calibration is below:I used the 4.01 solution (instead of the 10.01, which I am saving for another time) and found that it takes a long, long time for the readings to stabilize before you adjust them. I recommend making yourself a coffee, watching something on youtube, or walking your dog. It's going to be a while.Once I had it calibrated, I went crazy testing my pH dependent products. Vitamin C serum not tested or pictured because I am out. What fascinated me about this test was that the digital results were actually lower than what my pH strip estimates were, which was a good thing.After each test, I thoroughly rinsed the probe, dried it with Kimwipes, and stored/reset it in the 4.01 buffer solution while I cleaned and dried my other wineglass between products. I did not adjust the calibration each time I returned it to the 4.01, as I presumed I was contaminating the pH each time I double-dipped the electrode back into it, but it only went up to 4.07 by the end so I'm confident that at most it was reading my products approximately 0.06 higher than they really are.My original pH strip estimate was 3.5ish, which was fine for a BHA but I am pleased to see that this landed between 3-3.5 which is right in the 'butter zone' for BHA. If you use BHA and AHA in the same routine, your BHA will be first for two reasons: 1. it has a lower pH dependency than AHA, and 2. BHA is oil-soluble so it can get down-n-dirty into your sebum-choked pores and do its battles there. This clears the way for AHA, which is not oil soluble and thus would otherwise have its efficacy reduced.Make sure the ones you get are 0-14, as some are meant for bodily fluids (I felt a bit dirty just typing that) and have a limited range. Then test away! Test bottled water for a control, test your tap water, test your acids, test your cleansers (especially your cleansers!), test any watery substance your curious heart desires. Feel free to rub your hands and cackle maniacally while you do it, that's part of the fun.Have you gone wild with pH testing testing goodies in your skincare wardrobe? Hit me up onorand let me know!Have something you'd like to share with me in general? Snap a pic and tag me on Instagram atbecause I'd love to see it!