The Water Phase Is Not Just Water — And That Changes Everything
By Cheryl Mitchell | The Hard Truth Mentor | Blog Post #3 | Lotion Foundations Series
In Post #2, I told you the water phase is where some of the most powerful customization in lotion making happens. I meant that. And now I'm going to prove it.
Most beginners treat water like filler. Like it is just the thing you pour in to take up space while the "real" ingredients do the work. That is one of the most expensive misunderstandings in this industry, and I do not mean expensive in dollars. I mean, it's expensive in missed formulation opportunities. Everything you dissolve into it gets carried directly into your emulsion and ultimately onto and into the skin. Once you understand that, you stop seeing water as background and start seeing it as prime real estate.
Let's talk about what can live there.
First: The Rule About the Water Phase
Before I give you the ingredient list, you need to understand one non-negotiable: anything you add to the water phase must be water-soluble or water-dispersible. If it is not, it belongs in the oil phase or the cool-down phase, and putting it in the wrong phase destabilizes an emulsion or wastes an active ingredient.
Water-soluble means the ingredient dissolves in water. Water-dispersible means it does not fully dissolve but distributes evenly throughout the water with mixing. Both are fine for the water phase. Oil-soluble ingredients are not.
When in doubt, check the supplier's technical or formulation information. It will tell you which phase the ingredient belongs in. If there is no data sheet, find a different supplier.
What Can Live in the Water Phase
Here is a practical breakdown of the water-soluble and water-dispersible actives you are most likely to encounter as you build out this series:
Aloe Vera Juice (not gel — juice)
Aloe vera juice is a direct replacement for water. You substitute it for some or all of the distilled water in your formula at a 1:1 ratio. It brings soothing, skin-calming properties and a subtle slip to the finished lotion. The most commonly cited benefit is its ability to calm reactive or irritated skin, making it a natural addition to sensitive skin formulations. We will go into aloe vera powder in another blog post on its own, as that is my preferred way to make aloe juice/water.
One important note: aloe vera juice is a water-based ingredient, which poses a microbial risk. Your preservative system must be robust enough to handle it. This is not optional. If you are using a preservative already (and you must be, because this is a water-based product), you are likely already covered — but always verify with your preservative's technical data sheet.
Usage rate: typically 5–30% of the formula, substituted for distilled water.
Hydrosols (Floral Waters)
Hydrosols — rose water, lavender water, chamomile water, and others — are the byproduct of steam distillation when essential oils are produced. They contain trace amounts of the plant's volatile compounds, dispersed in water, which give them a gentle, authentic botanical character that plain water simply cannot replicate.
They can be used as a partial or full replacement for water, just like aloe juice. Rose hydrosol adds a subtle floral note and is often cited for its skin-calming properties. Lavender hydrosol is popular for its mild, familiar scent. Chamomile is one of the gentler options for sensitive or reactive formulations.
Important: hydrosols are perishable. They are natural water-based products with low preservative capacity on their own. Always source from reputable suppliers, check the shelf life and storage requirements, and make sure your preservative system is doing its job.
Usage rate: typically 10–30%, substituted for distilled water.
Niacinamide (Vitamin B3)
Niacinamide is one of the most well-researched cosmetic actives available, and it belongs in the water phase. It is water-soluble, stable across a wide pH range (ideally formulated at a pH of 6), and compatible with most common cosmetic ingredients.
What does it do? At usage rates of 1-6% (depending on the supplier), it is widely cited as helping improve the appearance of uneven skin tone, supporting the skin barrier, and reducing the appearance of pores. It is not a drug claim — but it is a legitimate and popular active that your customers will recognize and ask about.
In your lotion, you add it to the water phase and fully dissolve it before combining it with the oil phase. Niacinamide is sensitive to heat above 80°C / 176°F, so add it at the lower end of your water phase heating, or add it at cool-down if your water phase runs hot. Check your supplier's recommended addition temperature.
Usage rate: 1-6%.
dl-Panthenol (Pro-Vitamin B5)
dl-Panthenol is the cosmetic ingredient form of vitamin B5, and it is one of my personal favorites for lotion formulation. It is water-soluble, works across a wide pH range, and functions as both a humectant (drawing moisture to the skin) and an emollient (smoothing the skin surface).
At 1–5%, it provides a measurable improvement in skin feel in the finished lotion — a softer, more conditioned sensation on application and after rinse-off (or, in this case, after absorption). It also has a well-documented reputation for supporting skin barrier repair, making it useful in formulas for dry, compromised, or sensitive skin.
It goes into the water phase and dissolves easily. It plays well with nearly everything.
Usage rate: 1–5%.
Sodium PCA
Sodium PCA (sodium pyrrolidone carboxylic acid) is a natural component of the skin's Natural Moisturizing Factor (NMF) — the complex of compounds that keeps skin hydrated from within. As a cosmetic ingredient, it is a highly effective humectant, meaning it draws and holds water at the skin surface.
It is water-soluble, clear, easy to work with, and adds genuine moisturizing depth to a lotion without noticeably changing its texture or feel. It tends to work synergistically with other humectants like glycerin or 1,3-propanediol — they all do similar jobs at the skin level, and combining them often yields better results than relying on one alone.
Usage rate: 0.5–2%.
Hyaluronic Acid (Sodium Hyaluronate)
Hyaluronic acid is a word that gets used loosely in this industry, so let me be specific. The ingredient you are most likely to source as a cosmetic maker is sodium hyaluronate — the sodium salt form of hyaluronic acid. It is water-soluble, stable, and effective as a humectant.
The famous claim that hyaluronic acid can hold 1,000 times its weight in water is used widely in marketing. What matters for your formula is this: at the right usage rate, sodium hyaluronate adds a plumping, hydrated feel to the skin surface that customers notice and respond to.
It goes into the water phase. Hydrate it in your water before combining with the oil phase. It disperses better if you add it to cool or room-temperature water before heating, depending on your supplier's guidelines.
Usage rate: 0.1–2% (it is effective at very low concentrations — more is not always better here).
Your Formula Upgrade for Post #3
We are adding panthenol and sodium PCA to the 8-ingredient formula from Post #2. These are both water-phase additions, so we subtract their percentages from the distilled water.
Ingredient Phase % Grams
(227g batch)
Distilled Water Water 72.25% 164.0g
Xanthan Gum Water 0.25% 0.6g
Panthenol Water 1% 2.3g
Sodium PCA Water 0.5% 1.1g
Emulsifying Wax Oil 5% 11.4g
Stearic Acid Oil 4% 9.1g
Sunflower Oil Oil 7.5% 17.0g
Mango Butter Oil 7.5% 17.0g
Euxyl PE 9010 Cool Down 0.75% 1.7g
Fragrance or EO Cool Down 0.75% 1.7g
Total 100% 227g
We're now at 10 ingredients. Notice we are still not past 100%. Every addition comes from somewhere intentional.
What This Post Just Taught You
You now understand that the water phase is an active formulation decision, not a passive background filler. You know what category of ingredients belongs there, how to substitute them for distilled water without breaking your formula, and which specific actives are worth understanding first. And you made two real additions — panthenol and sodium PCA — in a way that reflects actual formula thinking.
That is meaningful progress.
What's Coming in Post #4
Next, we are going into the oil phase. Butters, liquid oils, emollients — the ingredients that give your lotion its skin feel, its richness, and its identity. We will talk about the difference between a lotion that absorbs clean and one that lingers on the skin, and how to engineer that difference deliberately.
Sunflower oil, mango butter, jojoba, sweet almond, shea — they are not interchangeable, and I am going to tell you why.
See you there.
This post is part of the Lotion Foundations series — Blog Post #3 of the Product Alchemy Series by The Hard Truth Mentor.
Cheryl | thehardtruthmentor.com
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— Cheryl | thehardtruthmentor.com | cheryl@thehardtruthmentor.com
