Shower steamer recipes
A steamer sized to your mould, at the essential oil load steam actually needs — around 4× a bath bomb's. No butters and no oils, because they do not evaporate and a shower floor is wet.
INPUTS
There is no field here for butters or oils, and there will not be one. A fixed oil does not evaporate, so it ends up on the floor of a wet shower with someone standing on it.
Batch size
: 1
Pressed at 1.15 g per millilitre — denser than a bath bomb. A gram of citric acid (anhydrous) uses 1.31 g of bicarbonate, so the rest is deliberate surplus.
Additives
AdditiveShare
%
%
Aroma — the whole point of the product
%
2–6%, about 4× a bath bomb.
%
Melt into the oil first. Ceiling 3%.
The reason most people make steamers at all. Not for a bathroom a small child uses — see the caution below.
The blocked-up blend is menthol-led. Keep it out of a bathroom a baby or young child uses — inhaled menthol is one of the few genuine cautions in this craft. The evening blend is the family one.
RESULTS
Essential oil for this batch
31.2 g
2.6g in each steamer 7.8g menthol
The blocked-up blend
| Oil | Share | Weight |
|---|---|---|
| Eucalyptus | 50% | 15.6 g |
| Peppermint | 30% | 9.4 g |
| Tea tree | 20% | 6.2 g |
Weigh out the powder
| Ingredient | Share | Weight |
|---|---|---|
| Bicarbonate of soda | 52.7% | 411.0 g |
| Citric acid (anhydrous) | 26.3% | 205.5 g |
| Cornflour (cornstarch) | 12.0% | 93.6 g |
| Kaolin clay | 4.0% | 31.2 g |
| Witch hazel | to feel | 20 ml |
| Butters and oils | none | 0 g |
Steamers from this batch
12
Mix per steamer
65.0 g
Batch weight
780.4 g
CO₂ released
141.2 g
No butters and no oils. A fixed oil will not evaporate, so it ends up on the floor of a wet shower — this is a slip hazard, not a recipe preference. Everything that scents a steamer must be volatile.
Keep the ratio to hand
The bicarb-to-citric ratio, binder rates and mould weights on one printable card. Free.
Get your free download
Bath Bomb Ratio Card
How this is worked out
A steamer is built the same way round as a bath bomb — the additives and the aroma are shares of the finished batch and the fizz base is what is left — but the numbers underneath come from a separate block in the reference data, so a bath bomb ceiling can never leak into one. Two things move. The essential oil load runs at 2–6% of the batch rather than the 1% a bath bomb takes, because the aroma is the product rather than an extra on top of it. And there is no field for butters or oils at all: they do not evaporate, so they stay on a wet shower floor. Mould fill is derived from the cavity's diameter and depth at 1.15 g per millilitre — denser than a bath bomb's 1.05, because a flat puck pressed with a spoon packs harder than a sphere twisted together in two halves.
base = batch × (1 − additives − essential oil − menthol)
acid = base ÷ (1 + bicarb:acid) 1:2 default, 1:1.31 exactly cancels
fill = π/4 × diameter² × depth × 1.15
essential = batch × 4% (a bath bomb runs 2% fragrance, 1% essential)
butters = 0 not a ceiling — an absolute
Questions makers ask
What is the recipe for shower steamers?
The same fizz base as a bath bomb at 1:2 bicarbonate to citric acid, plus cornflour to slow it down and clay to hold the puck together — and then several times the aroma. On a 12-steamer batch in a 60 mm cavity that is 411 g bicarbonate, 205 g citric acid, 94 g cornflour, 31 g kaolin clay and 31 g of essential oil — about 65 g of mix in each cavity. No butters and no oils at any point.
Why can I not put coconut oil or shea butter in a shower steamer?
No butters and no oils. A fixed oil will not evaporate, so it ends up on the floor of a wet shower — this is a slip hazard, not a recipe preference. Everything that scents a steamer must be volatile.
How much essential oil goes in a shower steamer?
2–6% of the batch weight, with 4% the working default — roughly 4 times what a bath bomb carries. The same batch as a bath bomb would take about 8 g of essential oil; as steamers it takes 31 g, or about 2.6 g in each one. The reason is arithmetic rather than enthusiasm: a bath bomb has a full tub of water to scent and a steamer has one shower's worth of steam.
What is the difference between a bath bomb and a shower steamer?
Shared: bicarbonate, citric acid, the same moulds and the same suppliers. Different: a steamer goes on the shower floor rather than in the water, its whole job is aromatherapy vapour rather than skin and colour, it carries around 4× the essential oil, colour is pointless because it washes away, and it must contain no butters or oils at all. That last one is a safety difference, not a preference, which is why the two have separate tools here.
Do I need menthol crystals?
No, but they are what makes a steamer feel like it is doing something for a blocked nose. 1% of the batch is a sensible starting load — 7.8 g on this batch. Dissolve them into the essential oil before it meets the powder, because menthol crystals will not disperse into a dry mix on their own. Past 3% they sting eyes in an enclosed bathroom rather than clearing a head.
Are shower steamers safe around children?
Eucalyptus, peppermint and other menthol-type oils should be kept away from babies and young children, who can react badly to inhaled menthol. At the loads a steamer runs, a shared family bathroom wants a lavender-led blend instead.
Why does my shower steamer disappear in thirty seconds?
It is sitting in the direct stream. Put it at the edge of the tray or on a shelf where splashback reaches it and the steam does the rest — under the spray it is simply dissolving. Cornflour (cornstarch) at around 12% also slows the reaction down, which is what it is there for.
What essential oils should I use?
For congestion, eucalyptus 50%, peppermint 30%, tea tree 20%. For a shared family bathroom, a lavender-led blend instead — lavender 60%, cedarwood 25%, roman chamomile 15% — because it carries no menthol-type oils. Fragrance oils work too and behave much like a bath bomb's, but a steamer is bought for what it does to your breathing rather than how it smells, and that is essential oil territory.
How long do shower steamers need to dry?
About 24 hours before they are hard enough to handle, the same as a bath bomb. They also need wrapping properly and quickly: a steamer's value is its essential oil, and unwrapped essential oil evaporates. A steamer left open on a shelf for a month is a fizzing disc that smells of nothing.
Read before your next batch
- How to make bath bombs One part acid to two parts bicarbonate, packed damp and left alone overnight. Everything else is detail — but the detail is where batches fail.
- How to make shower steamers Same fizz as a bath bomb, several times the aroma, and absolutely no oils — because a steamer sits on a floor someone is standing on.
- Where to buy citric acid Everyone sells it and almost nobody sells it in the size or the grade you want. Here is where to look and what to check before you order.
- Bath bombs without citric acid Cream of tartar is the usual answer and it fizzes far less. Here is exactly how much less, and the recipe that gets the most out of it anyway.