In terms of flavor profiles, most smoothies are very similar; most are based on sweet, fruity flavors sometimes accentuated by dairy. The Rhubarb-Citrus Smoothie is a smoothie of an entirely different breed. This Instructable will demonstrate how to make a Rhubarb-Citrus Smoothie, an acidic and slightly bitter yet sweet beverage that breaks the norm of docile, bland smoothies that we so regularly enjoy. Sip one of these smoothies on a hot summer day and it is guaranteed to satisfy.

Step 1: Ingredients and Equipment

The following ingredients will be needed for this recipe:

2 poundsRhubarb (fresh or frozen)
4 Limes
1Lemon
1 1/2 cupsGranulated Sugar
1 teaspoonVanilla Extract
Ice (the quantity depends on the smoothie consistency you want)

You will also need the following equipment:

A Blender
5 Canning Jars with Lids and Seals
A Sharp Knife

Step 2: Juice the Citrus

Juice each of the limes and the lemon by slicing each piece of fruit in half and squeezing it until it relinquishes all of it juices. Do not worry about pulp or seeds contaminating the juice, we will strain that out later.

Stash the juice in a refrigerator while you prepare the rest of the ingredients.

Note: If you use a fine quality knife to cut the citrus fruits in half, it is important to wash it as soon as you are finished. The acidity from the fruit can damage the steel.

Step 3: Rhubarb Juice: Prepare the Rhubarb

The first step towards the creation of your rhubarb juice is to prepare the rhubarb. First, cut the rhubarb into thin slices and place the slices into a pot. Using a very sharp knife for this will make the process much easier because the skin on the rhubarb stalks is quite tough and stringy. The good news is that the skin also contains a lot of flavor, color, and nutrients.

Second, after all of the rhubarb has been cut and placed into a pot. Add one cup of the sugar to the pot along with enough water to almost cover the rhubarb. Give the contents of the pot a stir to ensure that all of the sugar is dissolved.

Step 4: Rhubarb Juice: Cooking

Move the pot full of rhubarb to your stove. Cover the pot with a lid if you have one and heat the pot until the liquid inside comes to a rolling boil.

Then, take the lid off and boil uncovered for another ten minutes. During this time, the rhubarb should break up and turn into a kind of mush with much of the juice making its way into the water in the pot.

Quick Science Fact: The sugar you added to the pot of rhubarb plays an important role in extracting the juices from the rhubarb. The addition of sugar makes the liquid surrounding the rhubarb more dense than the liquid in the cells of the rhubarb. As a result, osmosis pulls the liquid out of the rhubarb.

Step 5: Rhubarb Juice: Canning

It is now time to harvest the rhubarb juice from the pot. First, get a second pot or a large measuring bowl or anything else that is heat-resistant and has a pouring spout. Put a strainer over the second vessel. Then, using extreme caution and oven mitts, pour the contents of the first pot through the strainer into the second pot. Stir the liquid in the strainer in order to coax the liquid through. By the time you are finished, you will be left with a semi-transparent, pink liquid.

Feel free to taste the rhubarb juice once it has cooled. It is very acidic and somewhat bitter yet sweet. It is actually refreshing to put on ice and sip.

A bit about rhubarb's nutrition: Rhubarb is a fairly nutritious vegetable. It has no fat and little sugar. It is high in calcium and vitamin C. It also contains vitamin A, iron, protein, and fiber.

Step 6: Make the Smoothie: Part 1

First, place a strainer over the pitcher of your blender. Pour two cups of rhubarb juice and the citrus juice through the strainer and into the blender. Then, remove the strainer and add the remaining 1/2 cup of sugar and the vanilla extract to your blender. Blend on a medium setting until all of these ingredients are thoroughly mixed and the sugar is dissolved.

Step 7: Make the Smoothie: Part 2

Add the ice to the blender and blend on high speed until all of the ice has been broken into tiny pieces. During this process the smoothie will probably produce a thick foam. This foam is rather tasty and gives the smoothie an interesting aesthetic appeal.

Step 8: Enjoy Your Smoothie

Congratulations, you have successfully created your very own Rhubarb-Citrus Smoothie. Pour your smoothie into glasses and enjoy. Feel free to experiment with the proportions of the ingredients in order to achieve a smoothie that is perfect for you.

Thanks for reading.