How to Make Bath Oil (and Exactly How Much to Put in the Tub)

A bath oil is the cheapest upgrade in this whole house. Two ingredients, five minutes, no citric acid, no fizzing, no mould, no waiting for anything to cure. You make a little bottle of it, you keep it on the edge of the tub, and the bath gets better for the next two months.

It is also the one you are most likely to get wrong, because almost nobody tells you the two numbers that matter: how much essential oil goes in the bottle, and how much of the bottle goes in the tub.

Here are both.

The master bottle: 1/2 cup oil, 24 drops

That is the whole recipe.

1. Pour 1/2 cup of carrier oil into a clean bottle or jar. Sweet almond is the easiest place to start. Jojoba is the one that never goes rancid on you. Fractionated coconut is the lightest and the cheapest by volume.
2. Add 24 drops of essential oil. Lavender alone is a perfectly good answer. So is 16 lavender and 8 cedarwood, or 18 sweet orange and 6 eucalyptus.
3. Cap it and roll it between your palms for about ten seconds. Do not shake it like a cocktail - you will whip air into it and it looks cloudy for a day.
4. Label it. In three weeks you will not remember whether the amber bottle is the lavender one or the eucalyptus one. Ask me how I know.

That bottle holds eight tablespoons, you use two per bath, so it is four baths. Double it if you bathe more than twice a week.

The dilution works out to roughly one percent, which is the number to hold onto. Two tablespoons of this in the tub puts about six drops of essential oil in the water - exactly where the safe range sits for a bath, and the same number we land on in how to use essential oils in the bath. That page covers which oils to skip and why the carrier is not optional. This page is just the recipe.

Which carrier oil, honestly

Most of the advice here is overcomplicated. Four real options:

• Sweet almond. Warm, faintly nutty, sinks in fast, cheap. The default.
• Jojoba. Technically a wax, closest to what your skin already makes, and it will not go rancid in a steamy bathroom. The one to buy if your bottle lives on the tub rim for months.
• Fractionated coconut. Thin, clear, odourless, stays liquid. Best if you hate feeling greasy.
• Grapeseed. Very light and very cheap, but it turns in a few months. Buy small.

Skip olive oil - it smells like dinner and you will notice at minute four. Skip mineral oil and baby oil, which sit on top of your skin rather than going into it, and make the tub twice as slick for half the payoff.

Mami says: If the bottle has been open more than six months and it smells like crayons, it is rancid. Throw it out, mija. Do not put it on your whole body.

When to put it in, and the part nobody warns you about

Fill the tub first. All the way, to the temperature you actually want. Then add the oil, and swirl it with your hand before you get in.

Pouring oil under a running tap seems smart and is not. The stream drives it straight onto the tub walls above the waterline, so half of it is a ring and only half is in the bath.

And then the warning, which is the real reason I wrote this page:

An oiled tub is genuinely slippery. Not slightly. Two tablespoons of almond oil turns the floor of your bath into something you need to think about standing up on. Nobody mentions this because it does not photograph well, so:

• Put a foot flat and test it before you commit your weight.
• Hold something. The tap, the rim, the grab bar if you have one.
• Get out slowly, and dry your feet before you step onto tile.
• If your tub is already a slick acrylic one, a cheap suction mat solves this permanently.

Then wipe the ring while the tub is still warm. Ten seconds now, five minutes later - the same logic as cleaning the tub fast.

The honest bit about “dispersing”

If you have read that proper bath oils disperse into the water and turn it milky, that is true, and it is because commercial ones contain a solubiliser - usually polysorbate 80. Without it, oil floats. There is no kitchen trick that changes this. Egg yolk, dish soap and vodka all technically work and all make a bath you do not want.

So be clear about what you are making. This is a floating oil. It sits on the surface as a thin film, and it coats you on the way in and again on the way out. That is not a flaw - it is most of the point. You come out already moisturised, which is why you then pat dry and stop instead of towelling yourself down to nothing.

If you want the milky-water version instead, that is a milk bath, and it is a different recipe.

The infused version, for when you have two weeks

This is the one worth making in October so it is ready in November.

1. Put 1/4 cup of dried lavender buds in a muslin bag and drop the bag in a clean jar.
2. Cover with 1 cup of carrier oil. The buds should be fully under.
3. Leave it somewhere warm and out of direct sun for two weeks. A kitchen shelf is fine. Give it a turn whenever you notice it.
4. Lift the bag out and squeeze it. That is the straining step, done - this is the entire reason for the bag.
5. Then add 12 drops of lavender essential oil to the finished cup. The infusion gives you depth and colour; the essential oil gives you the actual scent. Infusion alone smells like nothing much, which surprises people.

Chamomile works the same way. Dried rose is beautiful and smells faintly of tea. Oats do not infuse - if that is what you want, it is an oatmeal bath, not an oil.

Quick version if two weeks is not happening: stand the jar in a pan of hot water for an hour, twice, on two different days. It is not as good. It is a lot faster.

What this will not do

It will not fix dry skin on its own - that is a whole soak, and it is covered in the bath soak for dry skin. It will not make the water soft; that is salt’s job, and the dose is in how much bath salt to use. And a bath oil is not a treatment for anything. It is oil, and warm water, and twenty minutes where nobody can reach you.

Make the small bottle. Not the big one. You will want to change the blend by the third bath anyway, and a half cup is exactly the amount you can afford to get wrong.

Tonight: fill it, pour two tablespoons, swirl, and hold onto something on the way out.