An apple cider vinegar/acidic rinse corrects the pH of your hair, while conditioner “conditions” with the inclusion of a cationic ingredient (like BTMS-50 or honeyquat) as well as moisturizes it with oils and other nourishing ingredients.
An acidic rinse will usually be slightly acidic water, with that acidity coming from vinegar, lemon juice, kombucha, or powdered citric acid. The purpose of this rinse is to smooth the hair shaft back down after your alkaline (basic) shampoo bar raises the scales that make up your hair. If you don’t smooth them back down with an acidic rinse you’ll notice that your hair feels quite coarse and tangles really easily. If you don’t use a shampoo made from true soap with a higher pH, you won’t need an acidic rinse to counteract the effects of your alkaline shampoo. You can infuse your rinse with herbs, silk, tea, and other good-for-hair goodies, but the primary purpose of the acidic rinse is to smooth the hair shaft back down so your hair doesn’t catch on itself tie itself into knots. Understandably, this is much more important for people with long hair.
Conditioner can be a lotion or a solid bar. Lotion-y ones are usually mostly water with some oils emulsified in, often using the cationic emulsifier BTMS-50 to bring both conditioning and emulsifying to the conditioner. It can also have all kinds of other good-for-hair things in it like herbs, glycerin, honey, essential oils, and phytokeratin. The “conditioned” feel comes from the cationic (positively charged) ingredients, which adsorb to the hair, leaving an extremely fine coating that helps smooth, protect, and soften hair. Bar conditioners are usually mostly BTMS-50 (or some other solid conditioning ingredient) plus other hard ingredients (cocoa butter, cetyl alcohol, stearic acid), and some of the same good-for-hair ingredients like panthenol and hydrolyzed proteins.
Conditioner serves a difference purpose from an acidic rinse, though you’ll often read that an acidic rinse is a replacement for conditioner. This isn’t really true. The acidic rinse occupies the after-shampoo spot that conditioner usually does, so it can seemingly replace that part of your routine, but acidic rinses do not condition—they just pH correct. I’d recommend shampooing first, then using your acidic rinse, and then finishing up with some conditioner (being sure to use it sparingly and rinse it out quite thoroughly to avoid the greasies).
Posted in: General Usage