Okay This is driving me crazy!! I hope someone can solve this mystery...

Approximately 8 years ago I was doing a lot of stacked wedding cakes. I used the old Wilton Recipe with the ratio of 1 1/2 cups Crisco and 1/2 cup Salted Butter with 4 tablespoons milk, 2 teaspoons vanilla 1 teaspoon almond and a 2 lb. bag of Domino's10X Power Sugar. 

When I stacked my wedding cakes I used the Wilton smooth white opaque plastic plates that took the big white plastic hidden pillars that you could trim to use for each tier. I would bake on Wednesday, Crumb coat on Thursday, Ice/Stack and Decorate on Friday. Keeping the tiers in my refrigerator in between each step until I delivered. My buttercream cakes where very smooth, level and never cracked, nor had any blow outs (bowing). I did this for 10 years.

I stopped baking and decorating cakes and took a very long break, now after 8 years I have begun to bake and decorated again! I truly missed all the fun I had making cakes. BUT I am going crazy tiring to figure out why this is happening to me now.

I updated my recipe slightly to 1 cup Crisco and 1 cup Salted Butter, and 4 tablespoons of heavy cream. I also updated how I stack my cakes... I use 4 cake boards for my base which makes the base 1/2 Inch thick, I also put another cake board under the bottom tier. I use 3/16" Foam Core Board with a cake board on top of that on all the other tiers and then support them with the fat "Bubble Tea" straws and a wooden dowel rod that goes through all the tiers in the center (sometimes two depending on size).  

I do not have any problems when creating cakes that are not stacked.

BUT if I stack just one cake on top, I get this cracking or wrinkling on the top tier. 

I changed my shortening last week after reading a post to one that had some Trans Fat and it still happened, plus way more air bubbles! I did a 3 tiered cake that had this wrinkling on the top 2 tiers and a single wrinkle on the third tier.

I tried putting adding more liquid, but then the icing wouldn't crust. I tried putting a tile on each tier to get the air out and help in settling.

I also now do a very stiff dam of icing when using a filling and nothing has helped.

The only thing I do differently is after I have stacked the tiers and start to decorate them, I don't put it back into the refrigerator because my bakery seems to be warmer and I don't want the cake to sweat.

It just looks like the cake on the inside is shrinking and the icing starts to wrinkle on the outside.

The last cake I did, was fine... then after 2 hours of decorating and I was finishing the top tier when I noticed it had the same problem  :( 

The only thing I think it could be is the supports?? yet I read that what I am doing should be plenty of support. I am thinking of trying 2 - 3/16" foam core boards instead next time and perhaps a masonite board under the 4 base cake boards. (which now that I think about it I use to do 8 years ago.)

Any insight is very much appreciated!!! If someone helps me solve this I will send you a cake decorating gift!! Seriously!

Blessings to you and yours,

Kimberly

Hopefully you can see what i mean in these photos.. I smoothed the last two photos out before delivery, they were just as bad as the first photo. (click to enlarge)

I always bake on Wednesday, let the cake rest 24 hours, then crumb coat the next day (Thursday). In the past I wouldn't ice the cake until Friday, I would let the crumb coat rest a whole day. Now after crumb coating I let it set up in the refrigerator for several hours then ice each tier separately and return each tier to let the icing set up for several hours before stacking and decorating. I am wondering if keeping the tiers in the refrigerator while they rest is the problem... that chilling the layers isn't allowing the air to escape... perhaps because the tiers come up to room temperature while I'm decorating it causes the shrinkage?

Okay I will try adding the flour, should it be just plain flour or cake flour?

I do remember stacking my cakes on sight in the past and having to be very careful. The icing was not as dry/crusted as I see it now while decorating. The surface feels dryer.

2 sticks butter, 1 cup Crisco Shortening = 2 cups, 2 teaspoons of flavoring, a 2 lb. bag of Domino's Powdered Sugar and 4 tablespoons of Heavy Cream.

I am thinking of adding more either shortening or changing to a high ratio shortening, my local food supplier carries Wesson Quick Blend in 50 lbs as well as Sweetex in 50 lbs. I just didn't want to have so much at one time due to limited space.