These oil and water sensory bottles are SO PRETTY!! Make a DIY sensory bottle with two different colors that combine into one when you shake it. Then watch as the bubbles (and colors!) slowly separate again!
Sensory bottles are great for soothing and calming. But this color changing sensory bottle is also perfect for play and exploration. It’s a fun science experiment, and a mesmerizing fidget toy!
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How to Make Oil and Water Sensory Bottles
Check Out The Video Tutorial:
Step 1: Find what you need
- Gather your supplies and ingredients.
Step 2: Prepare the water bottle
- Grab an empty water bottle and rinse it out to make sure the bottle is clean. Once the bottle is dry, peel off the label.
- Add rubbing alcohol to a cotton round and remove any remaining glue and writing printed on the bottle.
Step 3: Mix and add the oil
- Add 2-3 drops of oil based food coloring into the baby oil. Regular food colouring won't mix with the oil, so it needs to be oil based.
- Use a stir stick to mix the color into the oil. Color doesn't mix very easily into oil, so keep stirring until the color is completely combined.
- Pour the colored oil into the empty water bottle until it's half full. Use a funnel if needed.
Step 4: Mix and add the water
- Clean your measuring cup, or grab another one, and add 3 - 4 drops of regular food coloring to the water.
- Stir until the color is combined fully with the water (this will be a lot easier than with the oil).
- Pour the water into the bottle on top of the oil. Fill the bottle up to the neck. Leaving a little bit of air in the neck will make it easer to combine the colors when you shake the bottle.
Step 5: Add the cap and enjoy!
- Add the lid back on your bottle, or glue it in place first if you'd like.
- Turn the bottle upside-down and swirl it back and forth to watch the colors combine.
- Your oil and water sensory bottle is complete!
- Now try making even more color combinations!
- If you’re worried about younger kids opening the bottle you can glue the bottle lid shut with hot glue or super glue.
- We like to use baby oil because it’s inexpensive and colorless. But you can also use cooking oil (which is yellow) or mineral oil instead.
Do the colors separate again?
Yes, the two colors in your sensory bottle will separate after the bubbles settle. Since oil and water don’t mix, the water will always fall to the bottom and the oil will always float to the top.
How do these oil and water sensory bottles work?
The colored water sinks to the bottom because it’s heavier (and has a higher density) than the oil. When you shake the bottles you make tiny bubbles of both oil and water which make it look like they’ve mixed together – and they’ll even create a new color!
But since oil is actually hydrophobic – literally meaning “fearing water” – the oil molecules push away (repel) the water molecules so they never actually mix. The water bubbles will always sink to the bottom, causing the oil and water to separate.
What color combinations look best?
Try to avoid colors that make the color brown when mixed together. In other words, make sure you don’t have all of the primary colors (red, yellow and blue) in the same bottle.
For example, green is made of blue and yellow. So if you have green on the bottom and red on the top, you’ll have blue + yellow + red which might look brown when you shake it up.
How long do these sensory bottles last?
The sensory bottles will last for weeks or even months – and the oil and water will never combine. However, the colors look best on the first day.
Our oil based food coloring must have still been somewhat water soluble because after one day, it started to separate from the oil and mix into our water. We were shocked to find that after 2 weeks the purple oil turned nearly clear in our purple and blue bottle!
Do I really need two types of food coloring?
Yes, you need to use two different types of coloring to make these DIY sensory bottles. The water can be colored with regular food coloring or even liquid watercolor paint.
But to color the baby oil you need to use an oil based food coloring, like a candy or chocolate dye. Regular food coloring is water based, so it won’t mix with the oil.
If you don’t want to buy special dyes, use vegetable oil (which is yellow) instead of baby oil. You’ll be limited on your color combinations, but it still creates a fun sensory bottle!
What water bottles are best for making DIY sensory bottles?
You can use any type of bottle (check your recycling first!), but for the best looking sensory bottle try to find a water bottle that has non-ridged sides. It makes it much easier to see the color mixing!
VOSS water bottles are the most popular choice for sensory bottles, and it’s easy to see why. The 500 mL bottles have a wide opening, making them easy to pour into. The bottles also have a flat bottom, and a nice flat silver cap. They make the sensory bottles look like something you could buy in a store!
Sparkling ICE bottles are another good option for a flat-sided bottle, although the opening is quite narrow, and the bottom of the bottle isn’t flat.
If you don’t want to use such a big bottle, check the dollar store for travel sized shampoo bottles. You can even use baby food jars to make a mini calm jar. Any container with a lid works, as long as you can see through it!
It’s so cool to watch the colors swirl and mix on these color mixing sensory bottles. They look SO PRETTY shining in the sun – they even cast shadows that are colorful!
Here’s even more sensory play ideas:
Our book Low-Mess Crafts for Kids is loaded with 72 fun and simple craft ideas for kids! The projects are fun, easy and most importantly low-mess, so the clean up is simple!