The Anniversary Cake Project: Lemon Butter-cream Icing

Additional installments of the Anniversary Cake Project:  lemon cake, lemon curd

With a lemon cake and lemon curd filling, it seemed natural that I should have lemon butter-cream icing.  Though I am a fan of Swiss meringue butter-cream, I chose not to use this for the anniversary cake project.   I did a traditional butter cream, with butter and shortening.  I based the recipe off of the Repressed Pastry Chef's Buttercream Dream Icing.  This is a great butter-cream recipe.  You might want to print it out because it is a good standby.  By the way, the cake in the photo above looks lopsided but it wasn't that way in person!

It is hard to figure out how much icing you might need to frost a cake.  I found some chart (I think it was Wilton) which indicated that for the sizes of cakes I was making, I would need to make 4 batches.  Each batch makes 4 cups of icing so that is a ton!  Above are the ingredients for 4 batches of icing.  Do you see the three bags of confectioner's sugar?  Yikes!

Anyway, I wanted to make the icing nice and zippy to go with the cake, so I added a teaspoon of lemon extract and 2 teaspoons of lemon zest to each batch.  It was delicious!

Start by creaming a cup of white shortening with 1 stick of unsalted butter and 1 stick of salted butter.  Once they are well blended, add the lemon extract and zest. 

Time to start with the confectioners sugar.  You must do this in batches to save your kitchen from a fine white coating of sugar that will go everywhere!  Sift a bunch of powdered sugar into the shortening/butter mix.  I added 2 tablespoons of meringue powder to each recipe, which helps stabilize the icing.  You don't have to do this, but I wanted to do what I could to increase my potential for success.  You need to add meringue powder with the confectioners sugar, so I put some in the sifter and sifted it right in.  If you look closely at the above photo, you can see that the meringue powder is a little bit of a different color than the sugar.  Thoroughly mix in the sugar and then add the rest in additional batches, with more meringue powder if you choose.

Then add very cold heavy cream until you reach the desired consistency.  I ended up using about 3/4 of a cup of heavy cream per batch to get the consistency I wanted for icing the cake.  Whatever consistency you desire, just make sure you add the cream very slowly so you don't go too far!   Add food coloring gel until you get the color you want.  I used 4 drops of Ateco lemon yellow gel. 

This giant bowl contains 3 recipes of icing.  At this point I decided to start working on the cakes, as this seemed like a tremendous quantity!  It is a good thing, as I had quite a bit left over so I definitely did not need that 4th batch.  I am not even sure I needed the third batch, but I did not measure the end amount.  It was quite a bit though...  I'd hazard to say it was about a full recipe!  I say it is better to have too much than too little!

Lemon Butter-cream Icing
adapted from the Repressed Pastry Chef
1 stick salted butter, room temperature
1 stick un-salted butter, room temperature
1 cup white shortening
1 teaspoon lemon extract
2 teaspoons lemon zest
2 pounds confectioner's sugar (powdered sugar, 10x)
2 tablespoons meringue powder - optional
 ~12 tablespoons very cold heavy cream

Cream the butter and shortening in the bowl of a stand mixer.  Add lemon extract and zest and combine well.  Begin to sift in the sugar a little at a time, mixing thoroughly after each addition.  If using meringue powder, add this with the confectioners sugar.  Once all of the sugar has been added and mixed well, begin to add very cold heavy cream, a tablespoon at a time, until you reach the desired consistency.
Printable Recipe

Time to work on the cakes!  I started with the 8 inch square layer.  The cake was a little bit shorter than the round cakes (I should have used more batter in the pans) so I decided to try adding a bunch of filling to boost it up a little.  So this layer had a double barrier of icing around the edge before adding the filling.  I used a size 12 tip for the barrier.

Here is a cake secret:  simple syrup.  I brushed the top of each layer of cake with a lemon simple syrup to help ensure a moist yummy cake (i.e., under the filling and on the very top).  Usually I make a simple syrup with water, sugar and some sort of extract, but this time I made it with lemon juice and sugar. 

I iced the outside of the layer and then inserted bubble-tea straws into the middle to support the next layer.  I did tons of research into how to support the layers and found lots of people who recommended these straws.  I found them at an Asian market for around $1!  I'll buy that for a dollar!  Score!  I had a 6 inch cardboard circle for the bottom of the next layer, so I held it above this layer to gauge where the supports needed to be.  I didn't want too many straws, making the cake more like Swiss cheese. but I wanted enough to be confident!  I probably did not need the middle straw, but that is okay.

Then I started on the 6 inch circle and repeated the process!

I gave this layer 3 straws to hold up the 4 inch layer.

Once all of the cake layers were iced, they all went into the refrigerator to harden the icing a bit.  After a couple of hours it was nice and firm and I was able to get the icing smoothed out.  I have never had success at smoothing icing before so I was really crossing my fingers!  And it worked!  I used a Viva paper towel (they are nice and smooth and soft) and pressed it gently over the icing and then rubbed lightly with my fingers.  The icing smoothed out nicely.  It was not a perfect smooth look like fondant, but for butter cream I think it worked pretty well!

I made some swirls and dots on the sides and top of each layer with a number 5 tip and put them back into the refrigerator.  I would bring the layers to my parent's church separately, and stack the cake there.  This is another activity I was a bit nervous about.  My sister said I was being Hermione Granger... reading a lot about something and deciding I could do it!  I just hoped I would be as successful as Hermione!