40+ years of making buttercream...and this happened as I was teaching my Granddaughter how to make BC. The ONLY thing I did different from my usual was add MILK instead of water (trying to make it more stable in my GD hot little hands) AND I added a about 1/8 tsp of orange oil (loranns). I've added orange oil before...so only thing really different was the milk. We used all shortening (with the trans fat) instead of half butter cause of her hot little hands...again.
The texture is NOT grainy sugary type of mouth feel...it is almost a fine curdled feel to the mouth. Actually my GD said it tasted as if we put some flour into it. We only use CANE Powdered Sugar...so that isn't the problem. Sugar was sifted and sifted again.
3 mins into beating...it was fine...still a little sugary to taste but exactly as expected. 8 mins into it was this mess. I've tried to whip it more but that doesn't help a bit. Needless to say...I won't let my GD even try to spread this onto a cake. It is so rough it wouldn't spread worth a darn even if we could get past the weird mouth feel. We went to plan B.
Ideas? Is it possible that the orange oil and the milk interacted and "curdled"? Can this be rescued for another day?
The silver lining in this is that my GD tends to want to be a perfectionist (at 9 yrs old) and stresses when she can't get a smooth iced edged cake. LOL! I keep telling her we need to be realistic...she is only 9 and not a professional and she is way better than most young wives would even be...but she just loves decorating cakes and tends to get disappointed when her vision isn't realized. :-) It wasn't her fault...it was mine I am sure cause I told her to put milk instead of water.