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Rainbow Jello

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Rainbow Jello is a local dessert that we grew up eating in Hawaii! Bright and colorful, it is fun to make (though requires patience) and even more fun to eat ^_^

Cubes of Rainbow Jello on a plate
Rainbow Jello cubes, ready to eat ^_^

Rainbow Jello

Rainbow Jello is a treat many of us local kids grew up eating. It's fun and colorful, and of course, pretty darn onolicious!

Rainbow Jello is a layered Jello dessert with alternating color and white layers. The white layers are made with sweetened condensed milk.

It's super easy to make. All you need is just a little patience (each layer has to set in the fridge before you can add the next layer).

A container of Rainbow Jello from Adela’s Country Eatery on Oahu
Rainbow Jello from Adela’s Country Eatery (Oahu).

A Hawaii Treat

Rainbow Jello is always one of the many popular offerings at potluck parties and family gatherings in Hawaii.

No one in your home makes it? It's ok, you can buy prepared Rainbow Jello from many supermarkets, delis, and food shops in Hawaii!

This popular dessert goes by a few names:

  • Rainbow Jello (classic and most common name)
  • Rainbow Finger Jello (because you eat it with your fingers)
  • Hawaiian Rainbow Jello (because of the Hawaii association)
  • 7 Layer Jello (4 color layers plus 3 white layers!)
  • Jelly Cubes (because they're served cut into cubes)

None of my mainland friends had ever heard about Rainbow Jello until they visited Hawaii. I don't believe this dessert originated in Hawaii, but it is often associated with Hawaii.

Ingredients to make Rainbow Jello (four Jello packs, Knox Gelatin, sweetened condensed milk)
Ingredients to make Rainbow Jello.

Ingredients

You need only three pantry ingredients to make Rainbow Jello:

  • 4 packages Jell-O - We use blue, green, yellow, and red, but you can use any color combination you prefer.
  • 6 envelopes Knox Unflavored Gelatin
  • Sweetened condensed milk - Carnation is the most popular brand.
Four image collage of the different Rainbow Jello layers: blue, green, yellow, and red
Blue layer first, then green, then yellow, and then red. The white/milk layer goes between each color layer.

Method

This recipe is easy. It also has many steps that need to be repeated. Read the full recipe (and the important tips in the section below) before you begin.

I like to think of this recipe as having 3 main sections:

Making The White/Milk Layer
The white/milk layers are made from sweetened condensed milk, Knox Unflavored Gelatin and water.

These layers are the most important component of the desert because it allows all the color layers to look separate/distinct. I also think it is the tastiest layer ^_^

Make a big portion of this mixture. Let it cool and use as needed between each color layer.

Make the Color Layers
The color layers are simple. Mix the Jell-O package with Knox Unflavored Gelatin. Then add hot water and pour it directly into a greased pan.

You can pour the mixture in the pan while hot for the first layer (blue color). For every additional layer, make sure the liquid mixture is cool (otherwise it may partially melt the layer below).

The Actual Layering Process
The layering process is fun. It can also be a nerve wracking depending how "perfect" you want the layers to look. Try not to stress too much about this part.

Uneven pouring and setting lead to slightly off balanced layers. Air bubbles and pockets will also lead to imperfect layers. But alas! It's all part of the charm. And it all tastes good.

Let each layer set in the fridge before pouring the next layer. I let the first layer set for 30 minutes, and then each additional layer for 20 minutes.

You want the layers to be "just set." If it hasn't set long enough, the next layer might mix into the previous layer and you'll get a muddled layer. But if it sets too long, then the next layer won't "stick" to it.

Two glass containers of Rainbow Jello
Two pans of Rainbow Jello, ready to cut and serve.

Tips and Questions

Air bubbles.

Air bubbles are an unfortunate thing that occurs when making Rainbow Jello. Try to remove as many of the air bubbles as you can before letting each layer set.

There are two main ways to deal with the air bubbles:

- Pop the bubbles with a toothpick or spoon.
- Pour the liquid though a funnel. Touch the funnel spout to the side of the pan and the liquid will glide into the pan (instead of splashing).

Lumpy white layers?

We prepare the mixture for the white/milk layer at the very beginning of the recipe. This is the layer that is used between each color layer. By the time you're on the 3rd or 4th layer, the mixture for this white/milk layer might have cooled off too much and look lumpy.

There's an easy solution. Just microwave the mixture 10 seconds and stir.

You want to get the mixture hot enough to loosen up and for the lumps to go away. But don't make it too hot (otherwise when you pour the mixture into the pan, the heat will "melt" the color layer below it). You'll end up with muddled layers instead of distinct layers.

Create even layers.

I like to clear our a shelf in the refrigerator when making this dessert. If you set the pan on an uneven surface (eg. on top of other leftovers or dishes in the fridge ^_^), it will set unevenly.

So just make sure you place the pan on a flat and even surface in the refrigerator.

Make sure the Knox Unflavored Gelatin doesn't clump.

If you mix Knox Unflavored Gelatin with hot water, it will immediately clump. Don't make that mistake.

How do you make sure it dissolves smoothly?

For the white/milk layers - Mix the Knox Unflavored Gelatin with 1/2 cup cold water first. Mix until the gelatin is dissolved. Then add 1/2 cup hot water and finish mixing.

For the color layers - Mix the Knox Unflavored Gelatin with the Jello package first. Then add the 1 1/2 cups hot water.

Don't forget to grease the pan.

I can't emphasize this part enough. I once forgot to grease the pan and the whole bottom (blue) layer of the Jello remained stuck to the pan. Still tasty thought not nearly as pretty.

I grease with vegetable oil, though many old Hawaii cookbooks recommend greasing with mayonnaise (!)

Rainbow Jello Recipe

See below and enjoy ^_^

Cubes of Rainbow Jello on a plate

Rainbow Jello

Yield: One 9x13 inch pan (about 24 pieces)
Prep Time: 15 minutes
Cook Time: 2 hours 30 minutes
Total Time: 2 hours 45 minutes

Rainbow Jello is a local dessert that many of us grew up eating in Hawaii! Popular at family gatherings and potluck parties and sold at many markets and delis, Rainbow Jello is loved by all! It is fun to make (requires a bit of patience), and even more fun to eat ^_^

Instructions

    1. Prepare the mixture for the milk layers. Mix 1 cup sweetened condensed milk with 1 cup of hot water. Set aside.
    2. In another bowl, mix 2 envelopes Knox Unflavored Gelatin with ½ cup cold water. Mix to dissolve. Add ½ cup hot water to the gelatin mixture and mix again.
    3. Combine the gelatin mixture with the sweetened condensed milk mixture. Stir to mix evenly and set aside.
    4. Now we make the layers. Grease a 9x13 pan (or can use two smaller pans) on the bottom and sides.
    5. Layer 1: Combine the blue Jell-O and 1 envelope Knox Unflavored Gelatin in a bowl. Mix. Pour in 1 ½ cups hot water. Stir until evenly dissolved. Pour into the grease pan. Refrigerate for 30 minutes.
    6. Layer 2: Pour 1 cup of the sweetened condensed milk mixture over the blue Jell-O layer. Refrigerate 20 minutes.
    7. Layer 3: Combine the green Jell-O and 1 envelope Knox Unflavored Gelatin in a bowl. Mix. Pour in 1 ½ cups hot water. Stir until evenly dissolved. Pour the mixture over Layer 2. Refrigerate for 20 minutes.
    8. Layer 4: Pour 1 cup of the sweetened condensed milk mixture over the green Jell-O layer. Refrigerate 20 minutes.
    9. Layer 5: Combine the yellow Jell-O and 1 envelope Knox Unflavored Gelatin in a bowl. Mix. Pour in 1 ½ cups hot water. Stir until evenly dissolved. Pour the mixture over Layer 4. Refrigerate for 20 minutes.
    10. Layer 6: Pour 1 cup of the sweetened condensed milk mixture over the yellow Jell-O layer. Refrigerate 20 minutes.
    11. Layer 7: Combine the red Jell-O and 1 envelope Knox Unflavored Gelatin in a bowl. Mix. Pour in 1 ½ cups hot water. Stir until evenly dissolved. Pour the mixture over Layer 6. Refrigerate for 20 minutes.
    12. Cut into squares. Eat and enjoy ^_^

Notes

  • A recipe for Rainbow Jello is featured in numerous local community cookbook. Every recipe is slightly different and this version was adapted from Hawaii’s Best Local Desserts by Jean Watanabe Hee.
  • The recipe calls for 1 cup of sweetened condensed milk, so you will have leftover sweetened condensed milk if you use the usual 14 ounce can. What to do? Use it to make Avocado Smoothies!
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