Water into Wine...
I looked through a number of Magic webpages/online forums on the subject and there's only one very complicated chemical using way to do it -OTHER THAN using sleight of hand.
One magician described putting a large folded hankerchief over a glass of water. The corner of the kerchief had been soaked in red food coloring and dried beforehand. The corner dangled in the water behind the outstretched kerchief as it was laid on the glass. Kids examined the kerchief before it was placed over glass (the "nothing up my sleeve" moment).
I came across a number of discussions about the "problem" of demonstrating miracles as magic tricks. Something to carefully consider and explain to children.
I did a magic trick making the bitter water sweet (from Exodus story, posted at this website) and it was very well received. However, after doing the trick and entertaining "how did he do it" -I explained the trick to the kids and briefly discussed the difference between miracle and trick. I encouraged them to do the trick at home (retelling the story to others).
Show "PICTURES PAIRS"
Show a "common thing" (like water) and ask "how they turned into wine" ...."Something that signals God's Kingdom". Then show the picture's pair.
A small amount of money -> turning into a meal for a family.
A pair of hands turning into praying hands.
One child ->, two children hugging.
A seed -> a vegetable garden in the inner city
A stack of paper -> a printed Bible.
A glass of water -> Given to a thirsty man
A hand -> two hands praying
Have children search through magazines and clip "common things" and be prepared to tell us a story of how they could be used to become WATER INTO WINE SIGNS.