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 
attaboyix1 year ago
Why not beets? I would have thought that to be the obvious choice?
makendo (author)  attaboyix1 year ago
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.
Have you tried blueberry instead of red cabbage? Should be essentially the same indicator, more pleasant taste from what else gets extracted.
makendo (author)  jaegerschlager4 years ago
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 makendo1 year ago
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.
tinker2343 years ago
nice idea i wonder if i could make a virgn verison
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.
RDeUslar2 years ago
Hi, one of my students chose your instructable for their advertising workshop, they did the nameing, packaging and ad campaign, hope you like it.
That has nothing to do with this Instructable as far as I can tell.
makendo (author)  RDeUslar2 years ago
Good stuff - hard to make a drink made from cabbage juice appear sexy, but I think they managed it!
wb7ptr1 year ago
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.
ccrazed2 years ago
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.
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)  ccrazed2 years ago
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.
kcabral285 years ago
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)  kcabral285 years ago
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 makendo3 years ago
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)  belsey3 years ago
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).
ilpug3 years ago
I really really need to do this.
cmanuel14 years ago
Just dropping in to say "Awesome, Dude!" I've featured this on Dabbled.org today..

makendo (author)  DotatDabbled4 years ago
Hey, thanks Dot... funny, I never thought of it as creepy or Halloween-worthy... but dammit, you're right.
jgroenert5 years ago
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)  jgroenert5 years ago
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 makendo5 years ago
 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 Nyxius5 years ago
 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)  Nyxius5 years ago

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 makendo5 years ago
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 Nyxius5 years ago
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)  Nyxius5 years ago

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.

pandaboy2925 years ago
thats sweet. now only if i were old enough to drink.
makendo (author)  pandaboy2925 years ago
Thanks - but no problem, you get the same effect for non-alcoholic drinks - and also see http://www.instructables.com/id/The-Color-Changing-Sports-Drink-Mocktail/
awesome. ill have to try that. but where do u get citric acid?
makendo (author)  pandaboy2925 years ago
Try a health food store or specialty grocery store.
alright. thanks.
lime juice(and i would assume other citrus juices) works, thats what i used.
Can also use ground up vitamin C pills ( ascorbic acid ) to get the same effect.
Jodex5 years ago
The victory came to the right address :-) Althought I didn't vote for anybody :-P =/
makendo (author)  Jodex5 years ago
Well, that's a vote of confidence anyway! Thanks.
lobo_pal5 years ago
You should know that you can get poisoning from dry ice easily.
makendo (author)  lobo_pal5 years ago
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 www.mistystix.com/ - 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!
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.
Dry ice is actually quite safe to use in drinks - but you shouldn't touch it - wait for it be gone before actually drinking...as it can burn skin...
DHagen5 years ago

I haven't tried this yet, but *Five Stars* on the concept, the photography, and the text. I sent my son the link. Don't worry, he's over 21.

makendo (author)  DHagen5 years ago
Many thanks. As for the photography - I still rely on sheer volume rather than talent, but also learnt some good tricks from the AngryRedhead.
Phoghat5 years ago
Dry Ice is solid CO2, not related to liquid nitrogen at all except they are both hella cold. As the dry ice melts it releases CO2 gas which dissolves in the solution producing carbonic acid which neutralizes the baking soda.
makendo (author)  Phoghat5 years ago
Er... well, yes, the exception is the point of the metaphor.
Solid CO2 sublimes rather than melts at atmospheric pressure, hence the name "dry" ice.
vIQleS5 years ago

Dry ice isn't necessarily intended for use in food (or drinks) so it's possible that the process isn't up to the standards you'd expect for other stuff you stick in your food...

I used to stick dry ice in my coffee all the time (I do a lot of volunteer theatre) and I still do, but it'd be interesting to know what the manufacturing process is... Does anyone know?

Also - don't drink the dry ice or hold it for too long... :-)

makendo (author)  vIQleS5 years ago
How's it's made... so the food-grade stuff you can assume to be pretty safe.
Yes, agreed, don't eat dry ice, and it's best handled with tongs. 
_fatguy5 years ago
Brilliant. Thank you for writing this instructable.
makendo (author)  _fatguy5 years ago
Kaiven5 years ago
That is a very cool use of science! I need to start thinking of other harmless science tricks that can be used with food...
makendo (author)  Kaiven5 years ago
I have one more up my sleeve; no cryogenics next time :)
jmiksanek5 years ago
I'm so excited to try this next week!  I've made the indicator before and martinis before, but the combination is beautiful. 
makendo (author)  jmiksanek5 years ago
Thanks; enjoy! A couple of tips - it's tempting to add more indicator+baking soda to make the colour change more vivid, but you compromise the drinkability if you push it too far. It's fun to make, anyway, and if you keep the drink small, you get a nicer effect from the dry ice.
Jayefuu5 years ago
Very clever! I like that your kids wanted to try the mocktail version despite your warnings! It must have been exciting.
makendo (author)  Jayefuu5 years ago
Thanks. In fairness, they were mostly buzzed out by the dry ice rather than the colour change - they were REALLY impressed when I put a chunk in a jar of detergent+water :)
Good idea, that. My kid thought that baking soda + vinegar + detergent was really cool (I put it in an empty squeeze mustard bottle so that it would spew foam across the yard). He'd be totally chuffed with dry ice & detergent.... hee hee hee.
makendo (author)  AngryRedhead5 years ago
Despite what organic chemistry did to me, I still have a sweet spot in my heart for pH indicators and the clever use of everyday items in chemistry.  I don't think I'll be trying this one anytime soon if only because I'm not a huge fan of martinis, but I can appreciate the appeal of this drink better than the galliano and menthe.  :-P  Teasing!!!  Forgive me!  Maybe that makes me crazy, but I do like cabbage better than anise, and I can appreciate a bloody mary and other savory type drinks even if they aren't what I go for outside of hair-of-the-dog.
I love this comment, or more particularly, the first phrase in the first sentence. I'm with ya, sista. Strength.
Ro]x[as5 years ago
 Ha, yeah that sounds like it tastes awful, but smart thinking with using CO2 to make an acidic solution.  I guess dry ice does have something on the more glamourous liquid nitrogen.
makendo (author)  Ro]x[as5 years ago
 It's not bad if you like savoury drinks, but if you like sweet ones, stay well clear!
rimar20005 years ago
Very good, clear and educational.
makendo (author)  rimar20005 years ago
Thanks. I dare say the "Morphing Mocktail" would be better for both teacher and student; after consuming four of these in the course of "experimenting", my photography was getting decidedly wobbly...
Nice trick. I like dirty martinis, too.
makendo (author)  fungus amungus5 years ago
Thanks, me too. I only had green olives in the fridge, and they looked bad in the fushcia drink. Black olives though... well, next time I have dry ice, red cabbage and black olives in the house, I'll brew a filthy martini!