I go through quite a few of these little guys, and will sometimes use 2 different ones – partly to see if they bring the same result, and partly to try the occasional different brand. Pictured above: a batch of multi-vitamin cream is being tested. This cream has a generous dose of carrot extract, giving it a rich yellow color. The thickness of the product combined with its color makes it a bit tricky to get an accurate reading.
Drip – Don't Dip!
Testing a liquid product is as easy as dripping a few drops of the product onto a strip and waiting for the color to change. This can take anywhere from a nanosecond to 30 seconds, depending on what you are testing. I cannot recommend dipping a test strip into your freshly-made product!! An inferior strip or tape will bleed color into the product – spoiling it. I have on more than one occasion had to dump an entire batch and start all over due to an inferior PH testing product.
Testing the PH of cream or lotion is a little different. The strip needs to have product applied to it, then sit for a bit (sometimes up to 5 minutes) before it registers. To read the strip, blot the strip very carefully until the product is removed. I've done everything from completely stripping off the little squares to smearing color all over because I wasn't gentle enough when removing the cream/lotion.
Here is a new PH strip I am trying out at the moment. This one is a bit more annoying to use than my 'old faves' because the squares don't line up with the printed guideline. Also, the guideline is not an accurate enough rendition of the actual colors, so it's hard to match up. On the positive side, these strips do have a large range, going all the way up to PH 14 (more than I'll ever need).
These are my favorite test strips and I have used them for years. As you can see, they are both accurate and easy to read. One could ask why the heck I try other brands if I am happy with these. Truth: they're pretty pricey, and I will fall for special offers as easily as the next person – even on lab equipment and PH test strips!
PS: A couple of requests about PH testing prompted this post. I hope this has been helpful to you who asked, and not too nerdy for you who didn't.