How long do you have to age a shampoo bar?

If you’ve ever made a shampoo bar, you’ll know the last step is a rather ambiguous “age the bars” for what can sound like a rather random length of time. I decided I needed to know how long shampoo bars actually need to age before they’re ready to use. I also wanted to know if that aging time varied between different types of formulations and different ways of shaping the bars. So, I whipped and pressed up an experiment to figure it out with a bunch of spreadsheets and math, and I’m sharing what I learned in this post (and the partner video, of course).


Gentle Low-Lather Face Cleanser

If you’re looking for an ultra-gentle, super inexpensive facial cleanser for any skin type—this is it! You can make a kilo of this cleanser for about $10USD, and all of the ingredients are super versatile, inexpensive, and easy to get 😄
Gentle Low-Lather Face Cleanser

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The inspiration

This formulation was inspired by Cetaphil’s Gentle Skin Cleanser; I was really intrigued by the short ingredient list, especially since it seemed to be missing a key ingredient.

Aqua, Glycerin, Cetearyl alcohol, Sodium benzoate, Sodium cocoyl isethionate, Xanthan gum, Panthenol, Citric acid, Niacinamide, Pantolactone.

This mostly hydrous formulation contains fat-soluble cetearyl alcohol, but no traditional emulsifier. Would the Sodium Cocoyl Isethionate—a surfactant, but not typically used as an emulsifier—be enough to get the job done? This ingredient combination reminded me of an emulsifying wax I’ve seen for sale (but never used) with the INCI of Cetearyl Alcohol (and) Sodium Lauryl Sulfate (products matching this INCI include Lanette® W, Crodex™ A, Unibase N, and Vegarol EW 200).

Anywho—Cetaphil did it, so it must be possible… and I obviously had to try it myself 😄 I purchased a bottle of the Cetaphil cleanser and set to work!

The original cleanser is a hazy, semi-transluscent creamy consistency. It has a glossy appearance, and is relatively fluid—easily pumpable, but not readily pourable. It works up into a low, creamy lather that’s more like the balm-to-milk effect you get from a cleansing balm than the lather you’d generally expect from a cleanser. It can be used with or without water (with = work up with water + rinse, without = massage into dry skin and wipe off with a dry cloth—like a cold cream). It is very gentle, unscented, and generally quite a nice product to use.

Formulation overview

This cleanser is a simple emulsion with a very small oil phase of just cetearyl alcohol. Most of the ingredients are used at very low amounts; we know this because sodium benzoate (a preservative) is the fourth ingredient. Sodium benzoate is used at up to 1% in cosmetics, so we can be pretty confident we’ve hit the 1% line by the fourth ingredient. This means everything after the sodium benzoate is used at less than 1%.

The ingredients

All of the headers in this section are links to the free Humblebee & Me DIY Encyclopedia entry on the ingredient; please click to learn more!

Distilled water

This forms the bulk of the formulation, diluting all the other ingredients to safe and useful levels. We used distilled water because it’s boring—it doesn’t contain impurities like salts and minerals (which can mess with our formulations) that are usually present in tap water.

Learn more: Different waters used in cosmetic formulating


Glycerin is an inexpensive humectant that helps moisturize the skin and contributes to the silky, cushiony skin feel of the cleanser.

I was chatting about this formulation with Valerie from Simply Ingredients at the 2023 HSCG conference in Kansas City and it turns out she’s also duped the Cetaphil cleanser! Her formulation is slightly different from my take, using 5% glycerin vs. the 30% in mine. She tried my version and hypothesized the reason mine feels more cushiony than the Cetaphil one is because of the high glycerin content. I really liked the pillowy feel, so I kept that high level. You could certainly reduce the glycerin and use more water instead if you want to.

Cetearyl Alcohol

Cetearyl alcohol—a solid fatty alcohol—adds some fat/richness and boosts gentleness and viscosity. This is the ingredient that gives the formulation its hazy, translucent appearance.

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Sodium Cocoyl Isethionate (SCI)

Sodium Cocoyl Isethionate emulsifies and provides low lather & rinse-off. It’s a very gentle anionic surfactant, and paired with a very low usage level we get a very gentle final product.

Xanthan gum

Xanthan gum teams up with the cetearyl alcohol to further thicken and stabilize the emulsion. I’ve chosen soft xanthan gum as it has a far nicer, more refined feel and look than regular xanthan gum. Soft xathan gum creates clearer gels with silkier skin feels, while regular xanthan gum is much more snotty and creates hazy, cloudy solutions. You can use soft or clear xanthan gum (I haven’t noticed much of a difference between the two). I don’t recommend using regular xanthan gum, but if it’s all you can get, you can certainly give that a try. I’d use less (0.3%) as it is a bit more potent than soft & clear (use more water to keep the formulation in balance).

Vitamins B3 + B5

Two B vitamins bring some skin-soothing, barrier-boosting properties to the cleanser… though I am not terribly convinced they’re doing much between the low usage rate and the wash-off nature of the product. I included them because Cetaphil does, but I doubt you’d notice a difference if you replaced either or both of them with more distilled water.

Lactic acid

A tiny bit of lactic acid lowers the pH to ~5.2–5.5, which is a good range for skin cleansers. Mine is a 90% solution, but if yours is an 88% solution you can use that instead—that 0.2% difference won’t meaningfully impact the final product at the rate we’re using it. You could also use a different alpha hydroxy acid to lower the pH (citric acid, glycolic acid, etc.), but the amount required might be different, so be sure to test the pH and adjust as required.

Liquid Germall™ Plus

Our preservative! I chose this one because it’s water soluble and very easy to use. You could use a different water-soluble preservative if you want to (this formulation is pretty easy to preserve), but be sure to follow the guidelines for whatever preservative you’re using as its usage rate and pH needs could be different.

Learn more: Can I use a different preservative than the one you’ve used?

Relevant links & further reading

Gentle Low-Lather Face Cleanser

Phase A
0.4g | 0.4% Sodium Cocoyl Isethionate (SCI) (USA / Canada)
4g | 4% cetearyl alcohol (USA / Canada)
20g | 20% vegetable glycerine (USA / Canada)

Phase B
0.5g | 0.5% xanthan gum (soft) (USA)
10g | 10% vegetable glycerine (USA / Canada)
40g | 40% distilled water
0.2g | 0.2% panthenol powder (vitamin B5) (USA / Canada)
0.1g | 0.1% niacinamide (vitamin B3) (USA / Canada)
0.03g | 0.03% 90% lactic acid solution (USA / Canada)

Phase C
24.27g | 24.27% distilled water

Phase D
0.5g | 0.5% Liquid Germall Plus™ (USA / Canada)

Combine Phase A in a beaker or glass measuring cup that’s large enough to hold the entire batch (I used a 150mL beaker for this 100g batch).

In a second beaker, mix the xanthan gum and 10g of glycerin together until uniform. Add the vitamins, stir, and then mix in the distilled water and lactic acid. This is Phase B. Weigh that entire beaker, note that weight, and now we can move onto heating.

Place both mixtures on your hot plate or in a water bath. Fill a third small beaker or measuring cup with at least 30mL (1fl oz) of distilled water, and pop that on the heat as well—we’ll need it later (this is Phase C).

Heat on low until the cetearyl alcohol mixture is liquid and clear, and all three beakers are roughly the same temperature. For a small batch like this one, this should take roughly 20 minutes.

Once everything is all toasty, remove Phase A from the heat, and weigh in 25.27g of the hot distilled water (that’s the water from that third beaker—Phase C).

Stir stir stir, scraping down the sides constantly. The mixture will thicken into a really funky glossy, semi-translucent gel in a couple minutes.

When that happens, weigh Phase B, replace any water that evaporated while it was heating, and then add that to Phase A + C and stir to combine. Because there’s so little surfactant in this cleanser we don’t have to worry about kicking up a bunch of bubbles, but you still want to be relatively gentle so you don’t work too much air into the cleanser.

Once the cleanser is uniform, leave it to cool to room temperature.

When the cleanser has cooled off, all that’s left is adding the preservative and ensuring the pH is in a good place for our skin so the cleanser is as gentle as possible.

To preserve, weigh in 0.5g Liquid Germall™ Plus (Phase D).

To test and adjust the pH: create a 10% dilution by weighing 2g product and 18g distilled water into a small bowl or beaker and whisk to combine (wondering why we create a dilution to check the pH?). Check the pH with your pH meter. Depending on the shape of your bowl/beaker you may need to tilt it in order to fully submerge the sensor on your pH meter. The pH should fall in the 5–5.5 range. If it is lower than 4.5 you’ll want to raise it; if it’s higher than 6, you’ll want to lower it. Please read this article from Skin Chakra to learn more about pH adjusting.

Once you know the pH is in a good place, it’s time to package it up!

A pump top or squeeze bottle is a good choice for this formulation; I used an amber 100mL (3.3fl oz) pump-top bottle from YellowBee in the video, and a squeezey HDPE bottle with a flip-top dispensing cap from Voyageur Soap and Candle Co. for most of my test formulations. Both options work well.

Use as you’d use any foaming facial cleanser. I usually begin by using micellar water or an oil cleanser to remove any waterproof eye makeup. Next, I’ll work a small amount of this cleanser up with a splash of water between my palms, massage it into my skin, and then wipe my face clean with a damp microfibre cloth. Cetaphil says their cleanser can be used without water, so you can do that, too, for more of a “cold cream” style cleanse; simply massage a pump of the cleanser into dry skin and wipe off with a dry cloth.

Shelf Life & Storage

Because this cleanser contains water, you must include a broad-spectrum preservative to ward off microbial growth. This is non-optional. With good manufacturing practice and proper preservation, this formulation should last at least a year. Even with a preservative, this project may eventually spoil as our kitchens are not sterile laboratories, so in the event you notice any change in colour, scent, or texture, chuck it out and make a fresh batch.


As always, be aware that making substitutions will change the final product. While these swaps won’t break the formulation, you will get a different final product than I did.

  • As I’ve provided this formulation in percentages as well as grams you can easily calculate it to any size using a simple spreadsheet as I’ve explained in this post. As written in grams, this formulation will make 100g.
  • To learn more about the ingredients used in this formulation, including why they’re included and what you can substitute them with, please visit the Humblebee & Me Encyclopedia. It doesn’t have everything in it yet, but there’s lots of good information there! If I have not given a specific substitution suggestion in this list please look up the ingredient in the encyclopedia before asking.
  • If you’d like to learn more about the surfactants used and compare them to ones you might already have so you can make substitutions, check out this page and read this FAQ.
  • You could try a different fatty thickener instead of cetearyl alcohol, like C10-18 Triglycerides (Butter Pearls) or a blend of Cetyl Alcohol and Stearic Acid.
  • You can use less glycerin; prioritize keeping some glycerin in phase B to disperse the xanthan gum. Increase the distilled water to keep the formulation balanced.
  • You can use soft or clear xanthan gum. If you use regular xanthan, use less (0.3%) as it is a bit more potent than soft & clear (use more water to keep the formulation in balance).
  • You can replace either or both of the vitamins with more distilled water.
  • Read the blog post for information on substituting the lactic acid.
  • If you’re like to use a different preservative, please review this FAQ and this chart.
  • I don’t recommend incorporating an essential oil or fragrance oil as this cleanser is supposed to be simple and gentle.

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Gifting Disclosure

The glycerin, cetearyl alcohol,Sodium Cocoyl Isethionate (SCI), niacinamide (Vitamin B3), panthenol (Vitamin B5), Liquid Germall™ Plus, and brown pump-top bottle were gifted by YellowBee.
The soft xanthan gum was gifted by Formulator Sample Shop.
Links to Amazon are affiliate links.


3 Butters You Shouldn’t Ignore (and one you might want to)

If you’re anything like me, when you first got started in the wonderful world of DIY, shea butter and cocoa butter were two of the first ingredients you purchased. They’re fabulous, versatile butters, and I used (and continue to use!) them in all sorts of formulations. They aren’t the only butters out there, though—there are so many fabulous ones that can help you achieve buttery greatness and set your formulations apart. In this post I’m sharing three awesome butters you might not’ve worked with that I love. These butters aren’t really fancy or exotic, so you can use as the base for your formulations or blend them with other butters to create something unique and delightful.


I tried 6 different emulsifying waxes. Here’s what happened.

I’m often ask if I can use a different emulsifying wax than the one I used in a formulation. So, I decided to put six common emulsifiers to the test, using my Easy Emulsified Body Butter formulation (which uses Emulsifying Wax NF) as the sample formulation. Which emulsifiers work? How to do they change the formulation? Are any of them easier or harder to use? And—of course—which one created the best emulsified body butter?

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I tried 6 different emulsifying waxes. Here’s what happened.

The emulsifiers

The original formulation uses emulsifying wax NF, a very common emulsifier—that’s why I chose it! In this experiment I swapped it, one-for-one, with six different emulsifiers:

I chose these six because they’re the ones I’m asked about the most often, so I figure most makers should have at least one of these if they don’t have Emulsifying Wax NF.

The experiment

I made six 100g (3.5oz) batches of my Easy Emulsified Body Butter, simply swapping the Emulsifying Wax NF gram-for-gram with each of the test emulsifiers. To ensure I could tell each batch apart I included a wee bit of a different water soluble in each water phase (this also had the lovely side effect of creating a rainbow of emulsified body butters!).

  • Glyceryl Stearate (and) PEG-100 Stearate: Pink
  • Ritamulse SCG: Yellow
  • Cetearyl Alcohol (and) Ceteareth-20: Orange
  • Olivem© 1000: Teal
  • BTMS-25: Blue
  • BTMS-50: Purple

I’m afraid there’s not much reason to the order of the rainbow, but it sure is pretty 😄

The results


The first differences I noticed was in the making: some mixtures thickened up much faster than others, making it more difficult to create a smooth final product that wasn’t also full of bubbles. The versions made with Olivem© 1000 and BTMS-25 thickened up the fastest; fast enough that I wouldn’t choose either for an emulsion this thick if I had other options. This faster thickening wouldn’t be an issue if the finished emulsion was thinner, but for this formulation it was rather stressful.

The Ritamulse SCG and BTMS-50 versions thickened at about the same rate as the original Emulsifying Wax NF version, and the Glyceryl Stearate (and) PEG-100 Stearate and Cetearyl Alcohol (and) Ceteareth-20 versions thickener more slowly than the original version. I was definitely a fan of the slower thickening—it was far easier to get a smooth finished product as the emulsion cooled more evenly.


Somewhat unsurprinsingly, soaping-prone Olivem© 1000 made for a rather soapy finished product. I was surprised to find that Cetearyl Alcohol (and) Ceteareth-20 did too, though! It was nowhere near as soapy as the Olivem© 1000 version, but it definitely soaped.

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Skin feel

Glyceryl Stearate (and) PEG-100 Stearate

This is the first emulsifier I ever used to create emulsified body butters because it’s practically invisible in emulsions, and it doesn’t disappoint here. Soft, creamy, silky, gorgeous! Less waxy than the original version, too.

Ritamulse SCG

This version felt a wee bit drier/more powdery than the Emulsifying Wax NF original, which i liked. Soft, creamy, and lovely!

Cetearyl Alcohol (and) Ceteareth-20

A bit more fluffy than all the other versions, and a bit less waxy.

Olivem© 1000

Similar skin feel to the Emulsifying Wax NF version, but with more bubbles as it thickened quickly, so the in-the-jar consistency is a bit more aerated.


Rich, smooth, and lastingly cushion-y in a way only cationic emulsions can be. Lovely! This one is also more aerated due to the fast thickening. No fishy scent from the BTMS.


Gorgeous! All the beautiful skin feel of the BTMS-25 version, but with less air in it. No fishy scent, either. Satiny, glossy, rich, indulgent.


I’d say the one with Olivem© 1000 is my least favourite due to how much it soaps, which is something this emulsifier is known for. I don’t hate it, but it’s not awesome.

Both the Olivem© 1000 and BTMS-25 versions were faster to thicken as they cooled, making them harder to work with than the original Emulsifying Wax NF version (and the other emulsifiers in this experiment). It’s not a total deal breaker, but it means I wouldn’t choose either of these first for this formulation. In a thinner emulsion this wouldn’t be as much of an issue.

The BTMS-50 and Ritamulse SCG versions both moved at the same speed as the original, but I think both have better skin feels. Which one you’ll prefer will come down to how much you like cationic-ness in your skincare. I’m leaning towards the BTMS-50 version, but the Ritamulse SCG one is still gorgeous, and definitely my top natural pick.

I love how the Glyceryl Stearate (and) PEG-100 Stearate and Cetearyl Alcohol and Ceteareth-20 versions moved more slowly, but I think the Glyceryl Stearate (and) PEG-100 Stearate felt better and soaped less than the Cetearyl Alcohol and Ceteareth-20 version.

Out of all seven emulsifiers (the six in this experiment and the Emulsifying Wax NF in the original), I’d probably choose BTMS-50 or Glyceryl Stearate (and) PEG-100 Stearate as my favourite (for this formulation, at least… though experience tells me I love these emulsifiers in all sorts of things!). I love the conditioning goodness of the BTMS-50, but I can’t deny the slower thickening and the pillowy softness of the Glyceryl Stearate (and) PEG-100 Stearate is divine.

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Gifting Disclosure

The Emulsifying Wax NF, BTMS-25, and BTMS-50 were gifted by YellowBee.
The Cetearyl Alcohol (and) Ceteareth-20 was gifted by Formulator Sample Shop.
The Glyceryl Stearate (and) PEG-100 Stearate was gifted by Mystic Moments.
Links to Amazon are affiliate links.


The key to smooth body butters

Grainy, mealy, uneven body butters are the bane of any formulator’s existence. You’re dreaming of something silky smooth and divine, but instead your body butter feels like its full of sand… or perhaps you were promised a solid bar, but got oily slop instead. Bleh! Let’s learn how to solve all that 😄


Luxury brand formulation secrets for expensive-feeling lotions

Even though I make most of the skincare products I use, I still enjoy perusing the skincare departments at Sephora and airport duty-free shops—paying extra attention to the luxury brands. I sample, sniff, and examine ingredient lists like a lotion detective. If a single lotion costs 3x my monthly grocery budget, I want to know what’s going on 🧐 What formulation magic has that fancy brand used to create a product that feels like its worth $400?! Fancy actives and proprietary botanical blends definitely pop up quite a lot, but I’ve noticed five cheap, easy-to-implement strategies in heaps of luxury formulations, and I want to share them with you so you can make lotions that feel like magic 🤩