Remember my post on Red Velvet Cake and how I said I was experimenting to make my natural red velvet cake taste less like beets? Well, I’ve done it… I guess you could say I had a bakethrough.
I’m going to give a warning in advance that this cake does not taste exactly like a typical RVC, but it is still delightful. Plus, my version contains nutrients and antioxidants that are thought to help prevent diseases such as cancer. Can your typical RVC do that?
(Ok I’m not suggesting you eat huge amounts of this cake to get your antioxidants because I’m pretty sure the sugar and butter counteract any health benefits this cake may have… but still.)
I used the Joy of Baking Red Velvet Cake and the Country Living Chocolate Pumpkin Cake (using beets instead of pumpkin) as starting points for my experimentation because both of these recipes are very yum.
I also did a bit of research on making a natural red velvet cake, and I found that many of the cakes containing beet juice for colour were turning brown during baking. After delving into the science behind some natural red pigments I learned some ways to keep a bright red colour in the cake, naturally.
Anthocyanins and Betalains
Anthocyanins are pigments that are found naturally in many plants. They are responsible for the colour of roses, red cabbage, raspberries, and many others. While most red plants attribute their colour to anthocyanins, others, such as beets, have betalain pigments instead.
Betanin is a betalain pigment that is most often used as a natural food dye. I found a bottle of this natural red food dye at a health food store that was almost 20 dollars! I think I’d rather spend a couple dollars on some beetroot and make the dye myself. Like anthocyanins, the colour of betanin is pH sensitive. I did a little experiment with beet juice just to see how the colour would change with varying pH.
On the left is some beet juice that I’ve mixed with cream of tartar (an acid) and then painted on a piece of paper. On the right is beet juice that has been mixed with baking soda (a base.) Clearly, we can see that if we are going to use beet pigments to make our cake red, we want to keep the batter acidic.
Stability and Degradation of Betanin
It isn’t just changes in pH that can affect the colour of betanin. There are various factors that can change its colour:
- Metal ions
- Water activity
I was surprised to see such a contrast between the two types of beets. After seeing the dull brownish-red colour from canned beets, I started thinking and consulted the ingredients list on the can. Second ingredient after beets? Salt, which is one of the factors that will promote the degradation of betanin.
Use Beet Puree Instead of Beet Juice
So we know that using fresh, raw beet puree works better than using canned beets. What about using beet juice instead of beet puree? While using beet juice would probably be much easier than pureeing the beets, it will not work as well. Water activity is one of the factors that contributes to betanin degradation. While I’m not going to go into what water activity actually means, the more water present, the less stable the betanin will be. You will probably have noticed this if you’ve ever boiled beets. The water always turns brown before the beets do.
Now that is enough pigment talk. Here is the recipe:
Makes two 9-inch cakes or 24 cupcakes
2-1/2 cups cake flour (260 g)
3 tbsp. NATURAL cocoa powder (not dutch processed or dark)
1 tsp. salt
2 tsp. baking powder
1 tsp. cream of tartar
1 cup butter (225 g)
1 tbsp. vanilla extract
2-1/2 cups white sugar (500 g)
1/2 cup buttermilk (125 mL)
1/2 cup plain yogurt (125 g)
1/2 cup to 1 cup beet puree (from raw beetroot) (100 to 200 g)
1/2 cup raspberry juice (from frozen or fresh raspberries) (125 mL)
2 tbsp. white vinegar
2 tbsp. lemon juice
Now let me do a little explaining about my ingredients choices. I needed to use things that would keep the batter acidic (hence the cream of tartar, buttermilk, yogurt, raspberry juice, vinegar, and lemon juice.) Even cake flour is more acidic than all-purpose flour. Admittedly, it probably wasn’t necessary for me to use ALL these acids. However, I thought adding too much of one type would give the cake a funny flavour. For example, I thought adding 4 tbsp. of vinegar might be a bit much so I decided to use both vinegar and lemon juice. I encourage you to experiment with different combinations to suit your taste.
I used more cocoa powder and vanilla than I normally would in a Red Velvet Cake. This, along with the raspberry juice, was an attempt to mask the beet flavour.
You will also notice that I say 1/2 cup to 1 cup of beet puree. You will get a deeper red from using a full cup of beets, but also a slight beet flavour. You can get away with using a 1/2 cup, but any less and your cake will start going a more brownish red. It is all personal preference and how concerned you are with having a bright red colour. My taste testers went back for seconds even with a full cup of beets in the batter so either one tastes good.
Preheat oven to 350 F (175 C.) Grease two 9-inch cake pans and line the bottom with parchment paper OR line cupcake tins with paper liners.
Prepare beet puree and raspberry juice beforehand. Grate raw beet and then puree it in food processor to as fine a texture as possible (adding water if necessary.) You don’t want any chunks, otherwise you might get a mouthful of beet while eating the cake. The colour of the cake will also be best with the finest texture of beet puree.
For the raspberry juice, heat up raspberries in microwave until they become mushy. Strain to remove seeds.
Sift together dry ingredients and set aside.
Cream together butter, vanilla, and sugar.
Beat in eggs, one at a time.
In a separate bowl, mix together the buttermilk and yogurt. Whisk in the beet puree and the raspberry juice. Stir in the vinegar and lemon juice.
Alternate adding the dry and wet ingredients to the butter/egg mixture, mixing until combined.
Pour batter into the prepared tins. Bake cakes for 25-35 min (18-22 for cupcakes) or until toothpick comes out clean.
Allow to cool 10 minutes in the pan, and then completely on a wire rack.
Decorate with cream cheese icing.