Hi All - I have been asked to do a swimming pool cake with white fondant and blue jelly for the water. If I chill my cake in the fridge, can I pour the blue jelly straight onto the white fondant and then let it set or will it make the fondant sticky and bleed colour everywhere?

Any help would be most appreciated -even it it's from a "what NOT to do" point of view! I need this cake to be really good!

TIA.

I use colored gell for water, but if you must use jelly, I would make a good dam so it does not spread. Other than that you should be fine.

I made a pool of water out of gel-dyed piping gel once. I dug a hole in the cake, covered it in buttercream and poured the gel right in. It did not bleed at all onto the white icing.

Piping gel works great and you can color it any shade of blue color that you want. You can buy it or make it yourself. It is super easy to make. Below is a recipe that I got here on CC.

Ingredients
1/3 cup sugar
1 Tbsp. cornstarch (cornflour)
1/4 cup lemon juice
1/4 cup water

Instructions
Whisk sugar and cornstarch (cornflour) in a small saucepan. Gradually add juice and then the water.
Make sure there are no lumps.
Stir over medium/high heat until mixture boils and thickens. Color as desired.
Will last about a month or so in the fridge.

I put blue colored piping gel right on top of MMF on my Princess and the Frog cake:
http://cakecentral.com/gallery/1862283/1862285
It didn't bleed; but when we cut the cake it had made the MMF just a little 'gummy' but definitely edible.

I used blue raspberry jello for the pond in my frog cake (in my pictures). I was afraid that the jello would melt the fondant while setting up. So after I carved out a cavity for the pond in the cake and covered it with fondant I lined the pond cavity with a small piece of cling wrap.
When preparing the jello I cut down drastically on the water.

Then I poured the jello right on the cavity in the cake and let it all set in the fridge.

Later on I noticed that the water lilies that were put too close on the jello water where becoming really soft and one of them actually melted during delivery. I had to wipe/soak it off with paper towel.
Made me really glad I had put on the cling wrap lining on the covering fondant. Otherwise a bigger disaster could have happened.

I did blueberry jello with 1/2 the water for a bathtub cake- you can make a mold for it, the same size as the opening on your cake and slide it into place once it's set.