carbonated grapes

After finally being able to purchase seltz or CO2 chargers for our iSi siphons at Williams Sonoma (we had searched everywhere else in the area), we proceeded with our humble efforts to carbonate some grapes.  There has been quite a bit written on the subject using the iSi method and also info on using dry ice to achieve fizziness.

My first attempt was with whole red grapes in our 1l siphon with 2 CO2 chargers.  I left the grapes sit in the canister at room temp for 30 minutes before removing them to try.  They were very fizzy (I'm not equipped to measure fizziness in our kitchen so all of my observations are unscientifically relative) and lasted for about 10 minutes before they became noticeably flat.  You cannot really observe the carbonation from the picture, but they were definitely fizzy.  Each grape had split its skin from top to bottom.

We referred back to an old posting on Khymos that suggested also cutting the grapes and letting them sit under refrigeration overnight.  The explanations for this can be found on Khymos... interesting reading.  This time I had used green grapes and for some reason, there wasn't as much as a pronounced fizziness.  The carbonation also did not retain for more than a few minutes (although it's easier for CO2 to enter the grapes this way, it's also easier for it to leave the grapes).

I also experimented further with this batch.  In order to preserve carbonation in the grapes for future use, what method (besides leaving them in the iSi) could be employed.  Cryovac'ing them seems ideal... and also bad at the same time.  Although sealed very securely, would the process of 'sucking' all of the gas out of the package be detrimental to the carbonation in the grapes?  For that reason, or perhaps another, the grapes did not remain carbonated.  Maybe another experiment with whole grapes would yield different results, but as for now... this myth is busted!

One more note... I do not have a device for measuring carbonation in grapes, so all of this is purely observational.  In the end, we used whole green grapes, 2 CO2 chargers, 1 night in the refrigerator.  They worked out amazingly great... and were still carbonated as much as 20 minutes later.  We used them as an intermezzo for a wine dinner for 32 people with a seltzer shot of green grape gazpacho soda.  It was a fun break in the meal.  The soda base was made from a broth of green grapes and toasted almonds (a play on Spanish white gazpacho)... refreshing and ice cold!  Sorry, no picture of the intermezzo.

Comments

[Ed]

The reason the cryovac didn't work is becuase of your assumption...the only way this might work is if it were possible to inject CO2. Some machines have the option of adding gas...but I doubt this would work either.

The reason the ISI works is because of the pressurized gas being forced in, remove the pressure and you are going to lose fizz as far as I can tell.

Try carbonating compressed watermelon, then sprinkle the surface with turbinado and carmelize with a torch, add a crystal or two of maldon salt before the sugar sets...probably my favorite application of this technique thus far.

Another interesting effect of this technique, is that after the CO2 is lost the fruit seems more like itself. The pressure must do something similar to compressing them in a cryovac.

[Jim]

Yeah, putting it under a vacuum will draw out the CO2. Enough CO2 won't dissolve (partially react) in water to make something fizzy unless it is under pressure. That's why you can't just stick graped into a ziplock and inflate it with a charger. If you put it under a vacuum it does the opposite of pressurize it. In addition, refrigeration should increase the fizziness (technically, it increases the amount of CO2 in the water... it may seem less fizzy), as water holds more CO2 at lower temperatures than at high. It will also prolong the length of time the water retains the CO2 it absorbs.

[logicalmind]

I have done a couple of experiments with carbonated fruits using an isi siphon. I don't have anything to add beyond what you've presented, but there is one interesting observation I made that I could not quite understand.

I carbonated some watermelon chunks and once they were carbonated the sweetness of the watermelon was completely gone. It might as well have been carbonated cucumber when it was done. I wasn't quite sure why this happened. No other fruits I've tried lost their sweetness in this way. And the watermelon was perfectly sweet before the carbonation. Very strange.....

[chadzilla]

Is it because of the 'sourness' of the CO2 overriding the sweetness of the watermelon... although carbonated cucumber sounds pretty cool. Thanks for the idea.

[Chicken Fried Gourmet]

Wow something new I need to try in the near future

[Orges]

Hi,

I explained this in lamargaritaseagita one year ago, but I basically did the same as you.

It works very well with mandarin and orange (of course, with the segments). With some fruits the sourness (part of the carbon dioxide in water is transformed into carbonic acid) resembles the taste of too ripened fruits. In addition, the skin in grapes, cherrys or orange segments, seems to help preventing the lose of CO2 too rapidly and also to avoid damage (strawbeerys with a small scratch on their surface are almost squezeed).

Ways of keeping CO2? just fill an hermetic container with the fruits (a piece of dry ice will help)

[Martin]

You're absolutely right about the fact that CO2 both enters and leaves the grapes more easily when they are halved! A tiny wet surface is enough, given enough time, the CO2 will easily diffuse throughout the grape.

The only way you can force more CO2 into the grapes is by lowering the temperature (the solubility of CO2 in water increases with lower temperature). This means that once the pressure is removed, you'd better keep the grapes cool until serving as this will delay the loss of fizziness.

[chadzilla]

Actually, it was on your site that I learned of the temperature aspect of carbonation. You were absolutely right, and as a bonus... the grapes taste much more refreshing when cold and fizzy.

[kelly]

i did a whole tomato salad, vinaigrette inc., in the can for three hours and served it as a first with some dungeness crab, the vin took on a nice carbonation as well so the whole thing was a nice pile of moving bubbles-topped with a foamed corn emulsion it was kinda cool, seeing stable bubbles on top of the soda--my girlfriend showed me an ad in people (i don't have it in front of me) from a company about to launch a line of carbonated fruit for kids.

[chadzilla]

Yes. The tomato carbonation is definitely cool.
The company selling the carbonated fruit is probably the project of Homaru Cantu of Moto who is packaging a product called 'Fizzy Fruit' directed at kids. I'm not sure where to get it yet. One website said that it was available at Super Wal-Mart stores, but when we checked it wasn't there.