Tonight I decided to mix up some buttercream for some cupcakes tomorrow. It came out awful. I think I made several mistakes?

1. I used a King Arthur frosting mix, adding butter and shortening according to directions.
2. I had to put the butter in the microwave for about 10 seconds to soften it.
3. I also added blue gel coloring. As it mixed up, the consistency became sort of grainy; as if the ingredients were almost lumping together in tiny bits.

I've made frosting with shortening before; using the Crisco sticks and it's come out fine. This time I used a "natural" shortening from Whole Foods.

I don't know if it was the shortening, or the butter, but it was gross. I threw it out and tomorrow I'm just going to make it plain with butter and powdered sugar. The butter is out getting to room temperature right now.

Any tips on how I can avoid having to toss an entire batch again?

What is a King Arthur Frosting mix?? If you are already using crisco and butter, all that's left is PS and liquid and I add popcorn salt to cut sweetness. Another thing I learned was to beat it a good length of time. After I cream my hi-ration shortening and butters for like 5 minutes, I add my flavorings, cream again, then my PS mixed with salt alternating with my liquid. I let it go for about 10 minutes on #4 on my stand mixer. It's the best!! I'm guessing it was the natural shortening! Good luck!

It was this stuff:
http://www.kingarthurflour.com/shop/detail.jsp?id=1406

I don't know why I bought it. Obviously I got carried away while ordering online.

I honestly think it was the shortening. I have used the KA before with no problems when using Crisco.

I won't be able to get more shortening before making the frosting tomorrow. I can do an all-butter frosting, right?

I've ran up to walmart a couple times, which is the closest store to my house, to pick up things I've run out of real quick. And when I've bought their powdered sugar I noticed that my buttercream seemed almost gritty in texture. I won't use powdered sugar from there anymore because that's the only time I've had a gritty texture to it so I know that's the only thing it could have been that caused it. I didn't use any thing else that was different. Did you use a different brand of sugar? Just a thought....

Been there -done that!! My DH thinks I'm the queen of online ordering!! Did you follow the directions on the box exactly??? If you did, it should have turned out, since King Arthur is so reputable! If your only change was the natural shortening, I'd lean towards that being the culprit!!

I've never used a frosting mix before, but I know that when I make it from scratch if I don't sift all the dry ingredients, it comes out grainy

I did follow the directions. I had this happen to me once before, when I made a vegan frosting with vegan "butter" I got in the organic section. I wonder what the difference is between organic shortening and crisco?

Or maybe it's because I thawed the butter in the microwave. Waaah. I hope it comes out okay tomorrow!

Edited to add: I found out the difference - palm oil.
http://fanaticcook.blogspot.com/2004/11/new-shortening-for-pie-crust.html

I have had this happen to me a few times actually. From my experience, it usually happens when I have microwaved the butter. I will start to see it look like it almost is separating a little bit and then it kind of has a grainy texture to it. I just put it in the fridge for about 15 min and that usually does the trick.
HTH

Maybe I should have tried the fridge before I threw it out in a hissy fit!!

Tomorrow I'll just do an all-butter frosting that I've done before, but I am going to try and experiment with the organic shortening sometime again and see if I can get it right.

I had the same problem tonight. Looked at the butter container, and sure enough, it was salted butter. Tasted awful too. YUCK! The salt in the butter, plus the teaspoon that was added really made it grainy.

Just an FYI out there if you need to soften butter and you don't have the time to let it sit out to soften... take out the butter and your trusty rolling pin and pound the butter untill soft. It is so much better than nuking it. And it works beautifully. HTH.

doescakestoo-Thank you soo much for that tip! I never even thought to do that. That will save me so much! Thanks

sugarbunz-I use salted butter in my bc all the time and it never gets grainy for me, unless I microwave it first, so that shouldn't have been the reason why you had problems. Maybe you were just tasting the extra salt you added...when I use all salted, I don't have to add any extra salt. I used to add salt to my all crisco recipe and I noticed I would taste salt granules every now and then so I started dissolving it first in a tsp of water. Others on here use popcorn salt because it is so fine. HTH