Sometimes the most learning happens when we admit we don't know as much as we thought we did. Recently we made a cheesecake and became perplexed when we added in fresh pomegranate juice in attempt to make a pretty (and tasty) swirl in our finished dessert. Funny thing is.... once we added it, nothing happened (until we added additional coloring)? What gives?!
We were ridiculously excited to use our fresh pomegranate juice (done by hand, not from a bottle) in a cheesecake for a family gathering. It was going to be beautiful, it was going to taste like a pink dream as it melted in your mouth, it was going to win hearts and make us the talk of the town... until it failed. The juice had no effect.
After a few minutes of head scratching we focused our attention on the science behind why our pomegranate addition kept our batter colorless. After all, 1 drop stains shirts, carpets, napkins and any other surface it comes in contact with, except cheesecake. We googled until we were blue in the face and couldn't come up with one logical reason why it didn't alter the color of our base mixture in the slightest.
Here's what happened (and can be seen above going left to right):
1. We made our batter (and tried not to sneak a spoonful of our tasty creation)
2. We gutted and juiced 3 perfect pomegranates.
3. Next we scooped out two cups of batter and put it in a separate bowl where we then added in 1 cup of pomegranate juice. Stirred to mix. Nothing happened.
4. We added the rest of our juice and there was only a slight color change. But not to the perfect pink we were expecting, in fact, it didn't turn a color at all. Our creamy colored batter turned white. White?! We added a known pink/red natural stain and it turned white. Needless to say, we didn't see that one coming.
5. We gave up, added a colorant from our baking supplies and went on our way. The end result tasted like pomegranates from the juice and had a cute pink tint, we just had to add that part in later.
Do you know what happened? What part of science class did we fall asleep in where that chemical reaction was explained? Let us know your best guess below!
Related: Cherry Cheesecake Ice Cream
(Images: Sarahrae)
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Dye is way more concentrated than juice. If you were to dilute your juice into water like 1:10 you'd have a faint pink juice----same goes with cheesecake. If I put orange juice into a cake it doesn't usually turn orange, etc. I don't think you're dealing with a chemical reaction here.
view sally599's profile
Try it with beet juice. Beet juice is the most powerful, natural reddish-pink coloring I know. Even a small amount added to a huge pot of soup turns it bright reddish-pink.
view quark's profile
I've used pomagranate juice to tint other things in the past (glazes and such) and hadn't had any trouble, maybe I'll sneak in some beet juice as well next time! Thanks for the tip!
view sarahrae's profile
yes beet juice
view pedalpowered's profile
was there lemon or other citrus mixed in at all? I have always heard lemon juice is effective on pomegranate stains!
view adamwa's profile
Pom juice (yes, I'm too lazy to spell it) will turn blue if you add the right stuff to it, so maybe that's why your cake turned white (blue yellow = white for the most part). I don't know what might have triggered the change, maybe an acid or something.
I have to agree with Sally599, though, there probably just wasn't enough colorant for it to make a huge difference.
view Tiamat_the_Red's profile
I have 3 possible ideas:
The red color in pomegranate is from the polyphenols -- namely anthocyanin and catechins/epicatechins. These compounds are soluble in water, not fat. A cheesecake has a lot of fat in it, so it's possible the pigments weren't dissolving and being dispersed in the batter.
Adding acid or base will shift the color to red or blue (as another commenter alluded). I would have to see the recipe, but it's possible the pH balance shifted the polyphenols to a blueish tint making your cake look more white.
And finally, as another commenter pointed out, there probably just wasn't enough juice to pigment the large mass of batter.
If you wanted to try it again, I would:
- reduce the pomegranate juice to a 1/4 of original volume; you can do this by boiling (and good for you for juicing your own!)
- add a little lemon juice to the juice (before or during reduction) to shift the pH to the acid side to make it more red (and prevent any oxidation while reducing); you can add baking soda to turn it more purple if you want
- mix the concentrated juice with the water/liquid ingredients before adding the fat (cheese, oil, butter, etc). This will help the pigments to evenly disperse.
- by concentrating the juice, you can now use more of it in the recipe without thinning the batter; adding a higher concentration of juice will of course give you more pigments and thus more color.
This is all just theory and based on my knowledge of food science and polyphenol chemistry (I did my senior thesis on polyphenols so they're my personal friend). If you try it again, please post a follow-up -- I've love to know if this worked.
Good luck!
view ilovebutter's profile
PS -- if you wanted to add baking soda to shift the color towards purple, only use a small pinch. Too much and it may turn yucky brownish. Good luck!
view ilovebutter's profile
This sounds like a good question for Shirley Corriher (sp?)-the food scientist that is often quoted in the NYTimes and also appears on Alton Brown's Good Eats.
view rosebud's profile
Ilovebutter has the right idea. Basically, Sarahrae, your cheesecake is oil. Your juice is water. Even in a really good processor, those two aren't going to fully combine. My suggestion is to add a LEETLE BIT (just a leetle bit) of an emulsifier to the batter/juice combo until you can get the two-cup bowl of batter and the juice to combine.
Known (natural) emilsifiers include egg yolk and some different oils. More here: http://www.foodadditivesworld.com/emulsifiers.html
Be aware, though, that you should always TEST what you're going to use before serving it at a party or for guests... Emulsion does some funny stuff sometimes, so you might have to play around until you find the perfect mix for your pomegranate cheese cake :)
view bfootnovellista's profile
I wonder if there is something in pomegranate that acts as a pH indicator ?
From a quick google search ...
http://marystevenson.wordpress.com/2009/02/15/pomegranate-ph/
view C&D's profile
@C&D -- the anthocyanins are a pH indicator shifting to red in acid (pH 7).
view ilovebutter's profile
@bfootnovellista -- I agree with the emulsifier. Eggs are usually in cheesecake (at least the recipes I have found), so combining the water ingredients, concentrated juice and egg yolks (lecithin) should be sufficient. You wouldn't need to add additional emulsifiers. 1 egg yolk can bind something like a cup of oil to a water-based liquid.
view ilovebutter's profile
If you want the pretty pink effect - you could try reducing down the pomegranate juice a bit and then setting it just slightly with a little tiny bit of gelatin (or agar agar if you would prefer) and then once it has coagulated just a bit swirling it through the cheesecake (having already filled your base/tin with the mixture) using a thin knife or skewer so that the pomegranate jelly (as such) gives you pretty pink swirls through your creamy mixture, plus you might get to taste the pomegranate a little bit more. I've done this with cherries before and it works really well.
view 218annandale's profile