Lotions and butters
The tiered lotion flow — the three phase presets, where the emulsifier is counted, the preservative floor Hi Ellie computes from your own pantry, and the pH window it asks you to confirm.
A lotion is a water phase and an oil phase held together by an emulsifier, with a short cool-down phase at the end. There's no lye anywhere near it — and there is a different hard requirement in its place: anything with a water phase must be preserved. Read Preserving water-based batches safely alongside this article; it's the safety half, this is the recipe half.
Five steps, three modes
Lotion is one of the two tiered Bath & Body products (the other is from-scratch soap), so it runs Guided, Collab or Advisor — see Bath & Body wizard modes. In Guided it's five cards:
- Style — the phase composition, picked as a preset.
- Oils — your carrier oils and butters, and the emulsifier.
- Preservative — from your Preservatives shelf.
- Scent
- Colour
Guided hides the phase-percentage sliders entirely and rides the preset's numbers straight through. Collab and Advisor expose them.
The three presets
| Preset | Water | Oil | Cool-down | Emulsifier |
|---|---|---|---|---|
| Light Lotion — fast-absorbing, everyday face/body | 75% | 20% | 5% | 4% |
| Everyday Lotion — balanced, all-purpose body lotion | 70% | 25% | 5% | 5% |
| Rich Butter Cream — thick, occlusive; hands, feet, dry patches | 60% | 33% | 7% | 6% |
The emulsifier percentage is counted inside the oil-phase figure, not on top of it — the recipe page says so under the number, so you never sum the four to 105. Everyday Lotion's 5% emulsifier is 5% of the batch and 25% of the carrier oils; those are two very different-looking numbers for the same wax, which is exactly why the page names its basis every time.
What the persisted percentages mean
The water and cool-down percentages Hi Ellie saves are reconciled against what actually ended up in each phase, so they can differ a little from the figures you typed — an input of 70 / 25 / 5 may read back as 73 / 25 / 2. The recipe page notes this beside the phases.
Small rounding drift is absorbed for you: if your three percentages land within half a point of 100, the app rescales them proportionally to an exact 100 before deriving any weight, so 60 / 30 / 10.2 is not a save you have to go back and fix.
Beyond that half-point tolerance it stops rather than guessing. The phase weights disappear from the recipe page, the bench sheet and the run walk — the app won't invent a formulation out of numbers that are genuinely wrong. It tells you why the weights are missing and what to change. New saves in that state are rejected outright.
The preservative floor
This is the number that matters most on a lotion, and it is computed, not suggested:
- Hi Ellie takes the preservative you actually stocked, reads its own on-file effective rate, and computes the minimum required weight for your batch.
- The recipe page shows it as Minimum preservative — a weight, for a stated batch size.
- It is a floor. Never go below it.
- Swap the preservative and both the floor and the working pH range move with it. They belong to that product, not to lotions in general.
If the recipe can't resolve a preservative — you picked none, or the one you picked carries no effective rate on file — the page reads Unavailable rather than filling in a plausible figure. That's deliberate: a dose the app can't stand behind is worse than no dose.
A lotion in that state still saves; it just can't be made. The gate is at the batch, not at the save. Start a Batch refuses it, in the words of whichever gap it found — "This lotion has no preservative selected — it can't be made as a batch until you add one to the recipe" when you picked none, and "This recipe's preservative has no usable dose rate on file — set its effective rate in your pantry before making this batch" when the one you picked carries no rate. Completing a batch refuses the same recipe for the same reasons.
The save refusals that do exist are narrower: a preservative your pantry no longer holds (the binding can't be resolved at all), and a rate above your pantry row's own documented maximum.
The pH window
A preservative only works inside its own pH range, so a leave-on lotion has a target: the overlap of your preservative's documented range and roughly pH 4.5–6.0. With no preservative bound, the recipe shows no target at all — a pH target means nothing without a preservative to keep effective.
The full reasoning, including which direction of miss is which problem, is in Preserving water-based batches safely. Confirm your batch with a strip or a meter before you bottle; don't reason from the recipe.
Scent, and why a lotion's ceiling is so much lower
A lotion is a leave-on product, and its fragrance ceiling reflects that: 1% of the batch, against 6% for a rinse-off bar. That's not a typo and it isn't caution for its own sake — the same fragrance has far less headroom on skin worn all day than in something you rinse off in ninety seconds. See Scenting a Bath & Body recipe.
The cool-down phase
The preservative goes in during cool-down, below its own heat threshold — heat destroys many preservatives with no visible sign that anything went wrong. Cool-down extras (a heat-sensitive extract, a vitamin) go in there too, and the wizard's ingredient swap will tell you when a material you're moving belongs in a different phase.