When you look at a cleanser formula and notice three or four different surfactants listed, do you wonder whether that's just "filling", or whether each one genuinely serves a purpose? In an ideal world, each is doing something different, and the combination makes the system work. The surfactant carrying the most weight in a formula is usually called the primary surfactant. Its job is the main cleaning function: removing oil, sebum, and debris from skin. It's typically the one with the highest percentage and is chosen for its cleaning efficiency and lather characteristics (this also means it tends to be anionic) . SCI (sodium cocoyl isethionate) and sodium lauryl sulfoacetate are common primary surfactants in rinse-off bar formats. The secondary surfactants come in to address things the primary does well at but not perfectly. Many effective primary surfactants can be slightly stripping on their own, so an amphoteric like cocamidopropyl betaine is added not necessarily for cleansing power, but to soften the overall action, improve skin feel, stabilise the foam and often to help thicken the formula. Some secondaries also boost the lather volume or quality, making the formula feel more luxurious without affecting the actual cleaning performance. There's also a third function that often gets overlooked: conditioning and mildness. Surfactants like coco-glucoside or even Lamesoft PO65 (refatting) can add a mild conditioning effect to the rinse, leaving skin feeling less tight. Non-ionics are gentler, so they pair very well with stronger anionics. The real skill in building a surfactant system is knowing what each ingredient contributes and in what ratio. A cleanser that's 100% primary surfactant will be harsher than it needs to be. A cleanser that's mostly secondary surfactants won't clean well enough. So the point I am trying to make is: find the right balance. Try this: Look at the INCI list of a commercial cleanser you like. See if you can identify which surfactant is likely the primary and which are secondaries. What does the combination tell you about what the formulator was going for?

Here's how it works: you drop a formula, a product idea, an ingredient question, or something you've been quietly puzzling over, and I give you proper, specific feedback. Not "looks great!" but actually useful input you can do something with. It can be the shampoo from the Abbey Yung series, something completely unrelated, or a question you've been sitting on for a while and weren't sure was worth asking. There are no silly questions here, genuinely. Post it below, and I'll work through them over the course of the day.

Most formulators know this in theory. Foam doesn't equal clean(s)ing power. A surfactant can cleanse perfectly well without producing a dramatic lather, and some of the harshest surfactants make the most impressive foam. But here's the honest question: do you actually believe it when you're the one using the product? I ask because I notice it in myself sometimes. I'll test a gentle cleanser bar that I know is working at a good surfactant percentage, pH is right, micelle formation is fine, and everything checks out. And yet if the lather isn't satisfying, there's a small part of my brain that questions whether it really cleanses. It's consumer psychology working on the formulator. We're not immune to it. Quick poll — when you use a low-lather cleanser, do you: Tell me in the comments, too. I'm genuinely curious whether this changes with experience level.

When I sit down to formulate a new cleanser, whether it's a liquid wash, a solid bar, or anything in between, there's almost always one surfactant I reach for first to kind of anchor the formula around, and then I build from there. I'm curious whether you have a default starting point too, or whether you approach each formula differently depending on what the product needs to do. My own starting point has actually changed over the years as I've worked with more surfactant types, which is part of why I find this question interesting to ask. It doesn't matter whether you're at the early stages of learning surfactant systems or you've been working with them for a while. Any answer is genuinely useful here. What's the first surfactant you reach for when building a cleanser, and what made it your go-to?

Sorry, gang, I need to move today's coffee hour to next Saturday (May 2nd). If you can make it, please let me know what time would work for you. I can do it all day until 7 pm (UK time), so it doesn't have to be evening time. Looking forward to chatting with you.