Introduction: The Color-Changing Martini

Picture of The Color-Changing Martini

This drink smokes elegantly, changes from a calm blue to fuschia as it cools from room temperature to drinkably cold, and tastes like a dirty martini.

(For the non-alcoholic, dry ice-free version, see the color-changing sports drink)

Step 1: Ingredients

Picture of Ingredients

You'll need:

Gin (or vodka, for a vodka martini) ~ Vermouth ~ Dry Ice ~ Baking Soda ~ Red Cabbage 

Step 2: Red #$@%! Cabbage?

Picture of Red #$@%! Cabbage?

Yes. Red cabbage contains a water-soluble anthocyanin that is a pH indicator. At low pH (acid), it's red. It's purple at neutral pH, and goes blue then green as the solution becomes alkaline. You're not going to see the full range here, because we want the drink to be, well, drinkable.

To get the indicator, chop up a cabbage leaf, put it in a bowl with some water, and microwave until it's boiling (or just add boiling water and allow to steep). A purple pigment will stain the water.

Step 3: Build

Picture of Build

Add a teaspoon of cabbage juice... I mean indicator solution - to the martini glass. Then add very small quantities of baking soda, just enough to turn the solution blue. Add gin (or vodka) and vermouth (~6:1) to the glass. You should have a pale blue clear liquid.

Step 4: Present

Picture of Present

Give the recipient the drink. Tell them to watch closely, then add a chunk of dry ice. It will sink to the bottom of the drink, and bubble away happily, slowly cooling the drink. It will also neutralise the baking soda and change the colour of the martini. See it in action in the video above.

(that's not me saying "wow, that's wicked" by the way. This drink was mostly made as a way of keeping three small children entertained while their mother was out Christmas shopping. They liked the look of the cocktail, but thought the mocktail version was "really disgusting". I did warn them that it was just salty, cabbage-flavoured water...)

It should go without saying, but wait for the dry ice to disappear before trying to drink the cocktail. You do NOT want to swallow any dry ice!

Step 5: Taste

Picture of Taste

In the interests of science, I tried some of the baking soda/indicator mix straight. Baking soda tastes salty on its own, and rather overpowers the cabbage juice. The latter by itself doesn't taste of much; a slightly sweet, vegetably taste, nothing like what its violent colour suggests. Overall, it flavours the martini in a way reminiscent of a dirty martini (martini with olive brine added). So you'll only like it if you like dirty martinis, probably a pretty small constituency.

I didn't initially regard this drink as spooky in any way, so was surprised to see it appear on various "Creepy Halloween Foods" lists (dabbled, neatorama, mentalfloss, etc). The lists were great and well worth checking out (they included some really effective eyeball recipes - see here for my version). 


GyroHeat (author)2016-04-21

Very fun, thanks, sorry I am late to join the question party but I will try none the less;

Could I make ice cubes out of carbonated water and use this to replace the dry ice?

It appears all you need is the indicator liquid-mixed with soda, then co2 to change the acidity,..right?....or replace the co2 cubes with frozen acidic liquid,...maybe pineapple juice?

makendo (author)GyroHeat2016-04-21

I think it is unlikely that you will preserve much CO2 in the ice cube. But yes, adding acid of pretty much any source will make it change color, see

I haven't tried it but you might even be able to just blow through a straw and do it with the CO2 in your breath.

Amhamlet (author)2016-04-01

Hi Makendo!

This is a great drink idea but was wondering if you had any ideas of changing the drink color to the color blue? Is this even possible considering blue is a primary color.

I'm having a gender reveal party and would love to have a drink that the end color turns blue...any suggestions?

makendo (author)Amhamlet2016-04-01

Yes, absolutely. Just start it off purple (you probably won't have to do anything to it - it's naturally purple - but if it is blue, add a *tiny* amount of acid). Add base (a weak baking soda solution) to make it go blue (add citric acid if you decide you want red, see for more details). Just make sure you experiment ahead of time, the quantities and strengths of what you add are crucial. Have fun!

attaboyix (author)2013-10-26

Why not beets? I would have thought that to be the obvious choice?

makendo (author)attaboyix2013-10-26

It's all to do with the pH at which the color changes. So beets have a great color... but they don't change unless you take the pH *very* high (12-13, and they go yellow). So this would create something undrinkable. It turns out blueberry juice isn't that great either - the change in that case happens at too acidic a pH. Cabbage juice anthocyananins turn out to be just right.

jaegerschlager (author)2010-12-09

Have you tried blueberry instead of red cabbage? Should be essentially the same indicator, more pleasant taste from what else gets extracted.

makendo (author)jaegerschlager2010-12-09

No, I haven't. Good idea though, as blueberries also contain anthocyanins. I was mostly looking for something that went with the salt. Any suggestions for a slightly salty, blueberry-flavoured cocktail welcome!

wb7ptr (author)makendo2013-10-25

Someone in one of the bars here in New Orleans is going to see this and steal your idea. That is if they haven't dreamed up their own version. That drink would be a hit here, especially during Mardis Gras.

tinker234 (author)2012-03-19

nice idea i wonder if i could make a virgn verison

wb7ptr (author)tinker2342013-10-25

The article has a reference to a "smoking sport drink" for those who don't drink alcohol. It's in the text above describing this version.

RDeUslar (author)2012-10-24

Hi, one of my students chose your instructable for their advertising workshop, they did the nameing, packaging and ad campaign, hope you like it.

wb7ptr (author)RDeUslar2013-10-25

That has nothing to do with this Instructable as far as I can tell.

makendo (author)RDeUslar2012-10-25

Good stuff - hard to make a drink made from cabbage juice appear sexy, but I think they managed it!

wb7ptr (author)2013-10-25

I had heard liquid nitrogen also. Dry ice is frozen carbon dioxide. The liquid nitrogen thing is some new fad going around. Hopefully it will end soon because it's causing a lot of harm.

ccrazed (author)2012-10-30

Not a great idea to use dry ice. A girl in the UK had a drink with dry ice and nearly died, she was lucky but had her stomach removed.

Green Silver (author)ccrazed2012-10-31

That was liquid nitrogen according to the news, she took the down in one challenge. I guess if the dry ice were to be placed under a gauze which was fixed to the glass it would be a whole lot more reassuring.

makendo (author)ccrazed2012-10-30

Yes, I would recommend those of a nervous disposition to stay well away from this drink, or to just make the drink change colour by adding a clear acidic drink (there are lots - Sprite works). I think it's fair to say in general that if you don't know anything about an ingredient, you should treat it with extreme caution (I think a guy recently died from eating live cockroaches in a competition). If you make a drink with boiling water and consume it before it cools, you will scald yourself extremely badly. So if we give someone a very hot drink, we warn them of that fact. Same principle applies here. Ingesting dry ice is dangerous, so wait for the cocktail to stop smoking before drinking it.

kcabral28 (author)2009-12-28

Just a thought, If you dissolved baking soda into water and then froze it into small ice cubes, would you be able to create alkaline ice and scrape off the sodium?  Isnt there a way to desalinate water by freezing it? Even if you can't remove the sodium from the ice maybe a slow release of base from the ice cubes as they melt would allow the color change to last longer or even swing back to blue after the dry ice completely sublimates? I'm definately trying this out soon.  Great idea!

makendo (author)kcabral282009-12-29

Thanks. Lots of ideas here! Freezing a salty solution generates ice + an even saltier solution, until eventually you'll start crystallizing out the salt (in this case, sodium bicarbonate) and you'll have a mixture of salt crystals and ice when the whole thing solidifies. I'd encourage you to experiment, for sure, but work it out with water first - don't waste all the booze! 

belsey (author)makendo2011-11-26

How about using potassium bicarbonate instead of baking soda? They do make it food grade and is used in specialty baking instead of sodium bicarbonate -- it should have a similar effect without the salt...

makendo (author)belsey2011-11-27

I'm sure it would work, but I'm much less sure that the effect of the potassium on taste would be beneficial. "Lite" salt substitutes about half of the Na in NaCl with K, but tastes pretty vile (it has a sort of bitter aftertaste, though YMMV).

ilpug (author)2011-10-17

I really really need to do this.

cmanuel1 (author)2011-03-31


DotatDabbled (author)2010-10-05

Just dropping in to say "Awesome, Dude!" I've featured this on today..


makendo (author)DotatDabbled2010-10-05

Hey, thanks Dot... funny, I never thought of it as creepy or Halloween-worthy... but dammit, you're right.

jgroenert (author)2009-12-27

I don't heat the cabbage. I make cabbage indicator for children's science classes by blending cabbage to a pulp with water. Strain and freeze xtra for later use.
Lovely drink . Would pickled cabbage brine work?Would add flavor . I am going to have to ask the local martini miester.

makendo (author)jgroenert2009-12-27

Thanks. Yes, you can see in the photo of the chopped-up cabbage that the colour is leaching out before the cabbage is heated.
Haven't tried pickled cabbage brine - but I think it's salty enough already!

Nyxius (author)makendo2010-02-13

 instead of using sodium bicarbonate to balance the solution why not use dilute 3% hydrogen peroxide?  it's not dangerous if consumed in the small quantities you would use in the drink.  Plus there is no salt as a by product... just plain old H2O.

If you try this method instead of baking soda, then I would strongly recommend mixing in the proper amount of peroxide into you indicator well before serving since the reaction is probably going to be pretty slow.

Nyxius (author)Nyxius2010-02-13

 Oh and just to give you the chemistry...

NaHCO3 & {H+ & (Ac)-}  --> Na?(Ac) & H2CO3 -->  Na?(Ac) & H2O & CO2

H2O2 & {H+ & (Ac)-} -->  2(-OH) & {H+ & (Ac)-}  -->  2(H2O) & (Ac)-  

(Ac)-   + CO2 -->  (Ac)-  & H2CO3  -->  {H+ & (Ac)-} & CO2

Worst case scenario is that you denature your indicator & it stops functioning...

makendo (author)Nyxius2010-02-14

Thanks for the suggestion... but H2O2 is a weak acid, not a base, so I don't see how it can replace the NaHCO3. It's also a strong oxidising agent, so as you say, there is a good chance it will bleach the indicator (which is another type of color change, of course!). I'm puzzled by the chemistry you've provided - is "Ac" the acetate ion (usually written OAc)? If so, the top reaction looks like baking soda + vinegar, but I can't figure out the next 2 at all.

Nyxius (author)makendo2010-02-14

Sorry...(Ac) is my personal notation for a generic anion (in this case...your indicator?).  Hydroxide is a weak acid like you said, but it is also unstable and usually decays into two hydroxide ions as a mid-step to creating stable H2O and O2.  The hydroxide ions function as your base to neutralize the acid by stealing the hydrogen to make H2O.  I was not sure about what other chemicals are in your indicator solution so the third line is just a guess of what happens after you add the dry ice (anions don't like staying anions from my experience).

Nyxius (author)Nyxius2010-02-14

This is a very slow reaction... can be sped up using ultra violet radiation.  Also dissolved oxygen will make the drink taste sweeter.

makendo (author)Nyxius2010-02-14

No, you're confusing anions with radicals... and oxygen is tasteless (just as well, or we'd be constantly overwhelmed with the flavor... in fact, I'm beginning to wonder if you're pulling my leg).
In case you're serious, my advice: DON'T make a drink with pharmacy peroxide. You really don't want to be consuming it (and unless you're sure the reaction has gone to completion, you will be). From the MSDS for 3% H2O2:
Ingestion: Large oral doses may cause irritation and blistering to the mouth, throat, and abdomen. May also cause abdominal pain, vomiting, and diarrhea.

pandaboy292 (author)2010-01-22

thats sweet. now only if i were old enough to drink.

makendo (author)pandaboy2922010-01-22

Thanks - but no problem, you get the same effect for non-alcoholic drinks - and also see

pandaboy292 (author)makendo2010-01-23

awesome. ill have to try that. but where do u get citric acid?

makendo (author)pandaboy2922010-01-23

Try a health food store or specialty grocery store.

pandaboy292 (author)makendo2010-01-24

alright. thanks.

revelae (author)pandaboy2922010-01-25

lime juice(and i would assume other citrus juices) works, thats what i used.

nanosec12 (author)revelae2010-01-31

Can also use ground up vitamin C pills ( ascorbic acid ) to get the same effect.

Jodex (author)2010-01-19

The victory came to the right address :-) Althought I didn't vote for anybody :-P =/

makendo (author)Jodex2010-01-19

Well, that's a vote of confidence anyway! Thanks.

lobo_pal (author)2009-12-29

You should know that you can get poisoning from dry ice easily.

makendo (author)lobo_pal2009-12-29

All the scenarios for poisoning that I can imagine are pretty bizarre. There are commercial devices designed, I assume, to stop drinkers accidentally or intentionally ingesting the dry ice in smoky cocktails - see - is that what you mean?
I would recommend those of a nervous disposition to stay well away from this drink, or to just make the drink change colour by adding a clear acidic drink (there are lots - Sprite would work). If you're really worried about safety, read the MSDS, which will completely put you off!

lobo_pal (author)makendo2010-01-05

Well, i heard about it from my friend, we're both freshmen chemical engineering students, so we thought it was really funny when we heard. She was at the party, but I was not.

Lobo_pal, the only danger of dry ice is how cold it is. The dry ice Osmcann is talking about is the solid form of Carbon Dioxide, which we actually create in our bodies and breathe in and out constantly. So, I would not worry about being poisoned by this substance, you are much more likely to give yourself frostbite.

I know that, I was referring to the fact that it is entering the stomach, and not the lungs. I am not sure why, but I have seen people get sick from it.

WNCmountaingirl (author)2010-01-04

Dry ice is actually quite safe to use in drinks - but you shouldn't touch it - wait for it be gone before actually it can burn skin...

makendo (author)2009-12-31

Thanks; glad you like it.

About This Instructable




Bio: Analog maker dabbling in digital manufacture
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