Flavor Mixing Straw




About: I'm an inventor / maker / designer based in the Bay Area. My background is in residential architecture, film set design, animatronics, media arts, exhibit design, and electronics. I use digital design and fa...

Instantly create custom beverages with the Flavor Mixing Straw! With around $10 in parts from the hardware store, you can turn three drinks into nine (correction: SEVEN. see comments) by turning a few valves.

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Step 1: Parts & Tools


1. 1/4" OD vinyl tubing (about 3' in length)

2. 3X 1/4" OD plastic quick-connect MIP straight valve

3. 1X 1/4" OD plastic quick-connect tee

3. 1X 1/4" X 1/8" plastic quick-connect C X MPT adaptor


1. Hand Drill

2. Scissors

Step 2: 3-Way Splitter

I couldn't find a 3-way splitter at the hardware store for 1/4" tubing, so I made my own. First, pick a drill bit that's slightly smaller in diameter than the threads of the adaptor and drill a hole in the top of the tee. Screw the adaptor into the hole using even pressure making sure to keep the adaptor level, and you should get a tight seal without having to tap threads in the hole.

Step 3: Measure & Cut Tubing

The bottle measures 9", so I cut the tubing that goes into the bottle at 11" to account for some wiggle room. The tubes connecting the valves to the tee are 2" long, and the straw end is 8" long.

Step 4: Assemble and Mix

To assemble, just push the tubing in until it stops. Now it's time to crack open some bottles and start mixing- with 3 drinks you get 9 possible combinations of flavors!



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    15 Discussions


    5 years ago on Introduction

    The valves are basically ball valves, so there is some control of how much flow you have, though they're intended for off/on usage. If you really wanted to get fancy, you could make little paper dials to fit under the valve handles with percentages on them. Another cool thing you could add to this project is some kind of bottle holding caddy.


    5 years ago on Introduction

    How are there 9 flavors?

    If each valve can only be fully on or fully off, there are two possibilities for each (on, off), so 2^3 = 8 combinations, but since one of them is all straws off, there are really 7 possible flavors.

    If each valve can be partially on/off, there are many more, only limited by the smallest amount each valve can be adjusted.

    3 replies

    To extrapolate, these would be the combinations:








    The last 3 aren't really combinations though, just the original drinks by themselves.

    Ha! Thanks for the correction guys. I didn't expect a project this simple to be scrutinized so carefully. Next time I'll do the math before I make such outrageous claims.


    but which is it? Can the valves be adjusted in small increments to find the best combination of flavors? If not, maybe it'd be a nice enhancement for the future.


    5 years ago on Introduction

    This is so silly - and I love it! Definitely a must build.


    5 years ago on Introduction

    Awesome idea! Multiple straws/split straws is nothing new - but the valves are - and that makes all the difference. Lovely update to an existing idea. Kudos!

    1 reply