Butter, shortening, and picking your problem
Okay, so butter versus shortening. People ask me this more than almost anything else, so let's just settle it.
I use real butter. That's my answer if you only want the short version. It tastes better, plain and simple, and taste is most of what people remember about a cake even when they're busy complimenting the frosting swirls. Shortening tastes like nothing. Some people like that — it stays out of the way of other flavors — but I didn't get into this to make frosting that tastes like nothing.
Here's the honest part though. Butter has a problem. It melts around 90 degrees, which sounds like a lot until you remember your hands are about 98 degrees and a July backyard party in American Fork can sit at 95 in the shade. Shortening doesn't budge until well over 115. So if you're making a cake for something outdoors in the summer, or somewhere with no air conditioning, or a car ride with the AC iffy, butter frosting can slide right off the cake before anyone gets a bite.
That's the trade. Butter tastes better. Shortening holds up. You don't get to have both, so you pick your problem based on what the cake actually has to survive.
What I actually do
For anything indoors, anything in cooler months, anything that's getting eaten within a couple hours of finishing it — all butter. For a summer ward barbecue or an outdoor wedding thing in July, I do a blend, usually half and half, sometimes leaning more shortening if it's going to sit outside a long time. You lose a little flavor but you keep your cake looking like a cake instead of a puddle.
If you're just starting out and this is a birthday cake staying in your own kitchen, don't overthink it. All butter. For sure for sure.
Basic buttercream, the version we're using tonight
- 1 cup butter, room temperature (not melted, not fridge-cold — actual room temp, soft enough to leave a dent when you press it)
- 4 cups powdered sugar
- 2-3 tablespoons milk or cream
- 1 teaspoon vanilla
- pinch of salt (people skip this and then wonder why it tastes flat)
Beat the butter alone first, a good three or four minutes, until it's pale and fluffy. Don't rush this part. Then add the sugar in stages — dumping it all in at once just means you're wearing it. Add the liquid a spoonful at a time until you get the texture you want. Salt and vanilla go in whenever.
If you're doing the blend for a warm-weather event, swap half the butter for shortening, same amounts otherwise. Shortening doesn't get quite as fluffy, so don't panic if it looks a little denser. That's normal.
Where elevation sneaks in
This isn't really a frosting problem, it's more a "why is my cake dipping in the middle under all this frosting" problem, but it's worth mentioning here because it took me three ruined cakes to sort out.
When I first started, my cakes kept sinking right in the center every single time, like a little crater formed while it cooled. I figured I was doing something wrong with the mixing. I wasn't. Up here at our elevation the air pressure's lower, so cakes rise faster and can overinflate and then collapse before the structure sets. I called my mom, who's baked her whole life at a lower elevation and had never dealt with this in her life, which was not helpful in the moment but did confirm I wasn't losing it.
The fix ended up being simple: a little less leavening than the box or recipe calls for, and a slightly hotter oven so the structure sets faster before the bubble collapses. Sounds small. Made all the difference. If your cake's coming out sunken and you're frosting over a crater instead of a flat top, that's probably why, and no amount of good buttercream fixes a structural problem underneath it.
A caution worth saying plainly
If you're doing the shortening blend, read your label. Some shortenings are still partially hydrogenated and some brands have moved away from that — doesn't affect how it works for us, but if anyone in your house cares about that, it's worth a look before you buy. Also, butter left out too long in a warm kitchen doesn't just get soft, it starts to separate and go greasy looking, and once that happens no amount of beating brings it back. Keep an eye on it, don't just leave it on the counter all afternoon and hope.
Before next time
Think about what your next cake actually needs to survive — a kitchen table for two hours, or a hot parking lot for six — and pick your butter-to-shortening ratio based on that, not just habit.