Build a Cloud in a Jar with Shaving Cream and Food Colouring

A cloudy afternoon in the Blue Mountains, a sudden downpour on the Gold Coast, or a fine drizzle rolling in across Perth — Australians spend plenty of time watching the sky. That natural curiosity makes a cloud-making experiment one of the easiest ways to bring weather science into the classroom or the kitchen bench. With a clear glass jar, a dollop of shaving cream, a few drops of food colouring, and some warm water, kids can watch a tiny cumulus form right before their eyes. It is fast, frugal, and ties neatly into the weather and water cycle strands of the Australian Curriculum.

Most of what you need is likely sitting in the laundry or pantry already, and the rest can be sourced from local discount stores or ordered online. The result is a thirty-minute investigation that feels more like play than a lesson, leaving children buzzing about evaporation, condensation, and the weight of water in the air.

Gather Your Materials

A short gear list keeps the lesson moving and avoids the classic "miss, the blue food colouring rolled under the fridge" moment. Lay everything out on a tray or a wipe-clean mat before the lesson begins.

You will need a clear glass jar with a wide mouth (a leftover pasta sauce jar works brilliantly), shaving cream, warm water, blue and a few extra shades of food colouring, a small cup or jug, and a pipette or a plastic syringe. A torch and a piece of dark cardboard behind the jar can help younger learners see the droplets forming clearly. For Australian teachers running this as a Year 1 to Year 4 science rotation, try to keep at least two jars on the go, with one student adding colour while another records observations.

Set Up the Cloud

The setup takes about three minutes, which makes it perfect as a "settle in" task at the start of a science block. Fill the jar roughly two-thirds full with warm tap water. The warmth matters because it encourages evaporation, which is what carries the moisture up into the cloud layer above.

Spray a generous, fluffy mound of shaving cream across the surface of the water. Aim for a cloud-like peak rather than a thin smear, because the cream needs enough thickness to hold the droplets that will fall through. Let the shaving cream settle for a minute while the kids predict what they think will happen when colour is added.

Drop in the Colour

Give each child a pipette loaded with blue food colouring. Hold the pipette just above the shaving cream and gently squeeze. Watch as the colour soaks into the cream first, then begins to drip down into the water below in thin, rain-like streaks. Resist the urge to stir — the whole point is that the colour falls through, mimicking real precipitation.

Repeat with extra shades if you want to show how different "storms" look. A red or orange drop can mimic a dust storm rolling over the outback, while a greenish hue often appears before a hailstorm. Encourage students to time how long the first drop takes to break through and compare results between jars filled with warm versus cold water, which doubles as great graphing practice on the side.

The Science Behind the Cloud

The shaving cream acts as a stand-in for the cooler air high above us where real cumulus clouds gather. Inside a real cloud, tiny water droplets cling to dust, pollen, or pollution particles. When those droplets grow heavy enough, gravity pulls them back to the ground as rain.

In the jar, the warm water evaporates and rises into the shaving cream layer. As the water vapour cools near the surface of the cream, it condenses back into liquid. The food colouring simply makes that condensed water visible, giving students a slow-motion replay of the water cycle they will revisit in Year 4 Earth and Space Science. Linking the experiment to local weather — a southerly buster, a Melbourne four-seasons-in-a-day day, a sunny Brisbane arvo — helps kids see that the science they just did actually describes the sky outside their window.

Adapting for Sensitive Learners

Some children dislike the smell of shaving cream or find the texture overwhelming. Sensitive versions swap the cream for thick, foamy dishwashing liquid, or use a clear plastic bag tied over the top of the jar so hands stay clean. Children with low vision benefit from a larger jar and squeezing the colour more slowly.

Providing a visual schedule on the desk and a finished jar model nearby takes the guesswork out of each step. The activity also slots neatly into group work, and adapted ideas for inclusive group projects can be found in the special needs adaptations guide, which walks through role cards and sensory-friendly tweaks.

Australian Curriculum Connections

This experiment fits comfortably within the Foundation to Year 4 Science strands, particularly the Earth and Space Science sub-strand that explores daily and seasonal changes. Older students can extend the activity into Chemistry by comparing plain water with soapy water to understand surface tension and how aerosols behave in the atmosphere.

Pair the experiment with a quick read-aloud such as Eric Carle's Little Cloud or a clip from the Bureau of Meteorology's kids' page, then ask students to predict tomorrow's weather using their newly built cloud-in-a-jar understanding. It also serves as a low-cost rotation during Term 2 or 3 STEM weeks when weather patterns are most changeable across southern Australia. For printable planning templates and substitution ideas, classroom teachers can browse the customer care page.

Extend the Lesson

Once the basic cloud has formed, the activity is a launchpad for follow-up investigations. Children can compare humidity by placing a wet cotton ball inside a sealed sandwich bag against a control bag, log the local temperature each morning, or sketch cloud types using the Bureau of Meteorology cloud chart. Older students might calculate how much water fell through by measuring the depth of coloured water at the bottom of the jar and converting that to millilitres.

A simple writing tie-in turns the experiment into a science report: students draw before-and-after diagrams, label evaporation, condensation, and precipitation, and finish with one sentence explaining what they learned. Pairing the report with a craft project, perhaps a cotton-wool cloud mobile or a water-cycle paper plate, turns a single demo into a full afternoon of learning that fits within an Australian school term planner.