I don't have a soda siphon - only a chemistry department. Inspired, I looked for alternative techniques.
The book on page 472 uses an alternative method to add fizz to an orange. According to MC take a plastic container with a tight-fitting lid and fill the bottom with dry ice (frozen carbon dioxide - be careful those pellets are cold cold cold! -78 degrees Celsius in fact) and if you happen to use a metal container to hold them, DO NOT touch it with your tongue like my son did...
Then place some paper towels or kitchen towel on top of the dry ice and place the fruit on top of that - this keeps the fruit from becoming frostbitten by the ice. Close the container and let the pressure build up inside - the lid may pop an number of times but just re-close it. After 30 minutes for grapes or much longer (overnight) for whole oranges or apples, you should have carbonated fruit.
I did try this but I think I did not have the right container because my fruit just got cold not fizzy. Here is an Instructable on another similar method: http://www.instructables.com/id/How-to-Make-Carbonated-Fruit/
So I began to think about other ways to maintain a pressure while allowing some release. No one at my Chemistry Department had a container that was big enough or could release pressure as needed. Then I thought of my handy dandy pressure cooker! It held pressure and could release the excess. So I tried it with the grapes - no luck. Turns out a pressure cooker only goes up to about 15 psi and I really needed at least 30 psi to get grapes to really fizz.
I then tried using my pressure cooker with watermelon - thinking that it is not so dense so would therefore absorb the gas faster. And it did! The pressure is too low to get visible bubbles coming off but the watermelon did fizz on the tongue. A big hit at the Chemistry Nuit Blanche food chemistry booth!
I forgot to take photos so I repeated the experiment recently using raspberries - yum!
I left them in for about 30 minutes.
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| Dry Ice at the bottom |
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| Raspberries on top of an insulating layer |
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| Odd to see the pressure up when it is not on the stove! |
I did find a couple of videos where they use a similar technique:
http://www.howcast.com/videos/421415-How-to-Make-Carbonated-Fruit
Next purchase will be a cream whipper - it does not only make whipped cream...it makes carbonated fruit!
Patricia, I love this idea because it is a repurposing of a tool more people should have in the kitchen anyway. Please share more!
ReplyDeletelinked here.
cheers!
I'm pretty sure you could also use a soda keg and carbonation, or even a carbonator cap and a PET bottle. Most homebrewers who have a keg setup and CO2 system could help you with that... kegs being set up to handle up to 100 psi, you could get a much more highly-carbonated fruit this way. I wonder what that would be like!
ReplyDeleteI tried breaking up the dry ice into small pieces and kept the fruit suspended over it in a metal colander, but ended up with no carbonation - just chilled fruit. I even tried one batch with the fruit directly on the ice, but they just froze solid. Is there something I'm missing?
ReplyDeletePerhaps your pressure cooker was not strong enough? Did it come up to pressure fully? The furit you use is impartant too - it has to be something fairly soft with a lot of liquid like pineapple or raspberries since the pressure is only at about 13 -15 psi in a pressure cooker. TO carbonate grapes and such you need to use the other method.
DeleteI tried carbonating the fruits in a regular container - not a pressure cooker. Some websites say it can be done without using a pressure cooker so I tried it that way. I used strawberries, grapes and orange supremes. Do you think using a pressure cooker would be a better idea?
DeleteI tried using a waterbottle to carbonate fruits too and it did not work too well - you need to have just the right amount of dry ice to create pressure but not enough to blow up your container and getting an airtight seal on a regular container is really tough. The pressure cooker is designed to hold about 13 psi so it can do soft fruits. A soda siphon is good for grapes since the pressure is much much higher >40psi and also designed for it. ONe other piece of advice is that cold fruit and containers work better since the carbon dioxide dissolves easier into cold liquids than warm.
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