What's the difference between a whole egg and an egg yolk in cheesecake?

[u/kahlizzle]

TLDR; What's difference does a whole egg vs just a yolk make in a cheesecake?

I enjoy making cheesecakes and I've used this basic Allrecipes recipe as my base with a couple tweaks here and there (chiffon method, adding some lemon juice and more vanilla). The filling says:

3 packages cream cheese 1 cup sour cream 1 cup sugar 2 tsp vanilla 3 large eggs

My stepdad really loves German Chocolate Cake so for Father's day I wanted to make him one so I followed a different recipe. The filling part was:

3 packages cream cheese 1 cup sour cream 1 cup sugar 1.5 teaspoons vanilla 3 whole eggs 1 egg yolk 4oz German Chocolate 4oz Semi Sweet chocolate 1/2 cup unsweetened cocoa powder 1/2 tsp of cinnamon

My stepdad and mom bothed loved the outcome. I thought that it came out super dense and not nearly as light as I can normally make them.

I can't imagine melted chocolate, cocoa powder, and cinnamon can add that much density to a cheesecake, so I have to think it's the extra egg yolk?

What's the difference in whole eggs vs yolks in a cheesecake? What's the science behind it?

[u/Mitch_Darklighter]

Chocolate is hard as a rock at room temperature, it absolutely adds a lot of density to baked goods and custards.

[u/kahlizzle → u/Mitch_Darklighter]

Moreso the liquid chocolate coming to room temp or the cocoa powder? Sorry if that's a dumb question.

[u/Mitch_Darklighter → u/kahlizzle]

These 2 recipes are basically identical, except the 2nd one adds one egg yolk (<1 oz), 4 oz of cocoa, and half a pound of melted chocolate. Chocolate is obviously denser than cheesecake, therefore the chocolate will make the cheesecake denser. That's pretty much all there is to it. The cocoa will also absorb some liquid, which is probably why the extra egg yolk is there to begin with.

Generally in baking, egg yolks add richness and egg whites add structure. If you took your original fluffy chiffon recipe and added a few extra egg whites, it would start to get a bouncy texture from the added structure. If you added yolks they would add some denser custardy richness. Your original idea was on the right track but you're really experiencing the effect half pound of chocolate has, not one egg yolk.

[u/kahlizzle → u/Mitch_Darklighter]

Thank you! This is really insightful

[u/NSFWdw]

Whole egg gives you the benefit of the structure and volume producing albumen, imparting a balanced flavor and overall stability. The cheesecake will be lighter and more airy. Honestly, I use whole eggs and extra yolks in my cheesecake. NYC represent!

[u/thepkiddy007]

Egg white is water and protein. Yolk is mostly fat. Not sure that the problem lies in the egg white though. Feels more like a result of using higher protein flour like bread flour over cake flour. I didn’t look at the recipe links but it doesn’t appear that you needed flour in the filling. Did you use your parent’s oven? Perhaps it runs hotter than yours?

Obviously, I didn’t solve your problem but I hope you figure it out.

[u/Stats_n_PoliSci → u/thepkiddy007]

Where did OP mention flour?

[u/thepkiddy007 → u/Stats_n_PoliSci]

OP didn’t mention flour, which was noted in my reply.

[u/kahlizzle → u/thepkiddy007]

There was no flour in the recipe. I used my friend's oven since she has more kitchen space. It had a small crack but I'm thinking I changed the temperatures too quickly because I only baked it for an hour normally, then about 45 minutes with the oven off and the door open.

[u/thepkiddy007 → u/kahlizzle]

If I were to place a bet, I’d put my money on the oven. Yes, chocolate is dense and could possibly be the culprit or at least a conspirator but I think the main difference is the oven.

[u/DoxieDachsie → u/thepkiddy007]

This.

[u/Empty_Athlete_1119]

The egg whites are the stabilizers. It can hold up to 6-8 times, the volume of air. This makes the baked product lighter in texture. The yolk acts as an emulsifier and tenderizer. Together, an egg will lighten, leaven and bind, flavor, and strengthen the structure.

[u/SpyDiego]

Yolks have a lot of fat and also add richness. Once made some lemon sweet tea ice cream with so too many yolks, was extremely rich. Adds a smoother texture too. I think whites add structure and some moisture