Bath bombs

A bath bomb is a dry acid/base mix that reacts the moment it hits water. No lye, no cure, no preservative — and, uniquely among the Bath & Body products, no batch. A bath bomb recipe is one bomb.

One bomb, not a batch

Everywhere else in Hi Ellie a recipe is a reference batch you scale. A bath bomb is a single mold cavity, so the wizard has no batch-size field at all, and the recipe page shows a single-unit weight where the other methods show a batch total. You choose how many you're making when you start a production run, and the amounts scale from there.

The four steps

The bath bomb flow is flat — the same four steps at every experience level:

1. Mold — one pick. A bath bomb has exactly one form.
2. Dry mix — your acid and base, plus any binder oil, from the Bath Ingredients shelf. This is a real add-another selector, not a single dropdown.
3. Scent — fragrance oils and/or essential oils.
4. Colour — colorants from your shelf, or none.

The hardening window

Instead of a cure, a bath bomb recipe carries a hardening window in hours. It's not a step you follow at the bench — it's what Hi Ellie times the production run's ready date from. The recipe page says as much right under the figure: "sets the ready date on a production run."

The window is the recipe's own number, set when the recipe was built. There is no house figure the app applies to every bomb, so if the one on your recipe doesn't match how you actually work, change it on the recipe.

The one thing bath water asks

Everything in a bath bomb ends up in a tub of standing water, and two things in a typical bomb won't disperse in water by themselves: the oils (carrier and fragrance both) and most colorants. Left alone they float, and what floats ends up on the tub.

That's the whole subject of Getting oil and colour to disperse in bath water — including the starting amount Hi Ellie works out for your bomb, and how to tell at the bath whether it was too much or too little. It's the article to read before your first coloured bomb.

Scent load

A bath bomb's scent is dosed against the total batch weight — the bomb's own weight — with a 6% ceiling, the same figure the from-scratch methods use. See Scenting a Bath & Body recipe.

What a bath bomb doesn't have

No lye acknowledgment (there's no lye), no preservative floor (there's no water phase to preserve), and no cure clock. What it does have is the hardening window and the dispersal question above — and a mix that packs badly if you overdo the oils. Weigh the dry mix carefully; it's the whole structure of the bomb.