Could it have been the humidity in the air today??

I made a batch of the no-fail last night to decorate with the kids today. I used Antonia74's icing, like I've done ever since she posted her tutorial...lol. Except today I had a horrible time with it...never had a problem before. It never would get as thick as it's supposed to while it was mixing...I let it go in the mixer for 15 minutes and still it was a bit on the thin side. I was afraid to let it go much longer. I'd added another 1/2 cup powdered sugar and it started to thicken up and eventually looked right. I turned the mixer off and got a few bowls and things together to mix up some different colors...it sat for maybe 5 minutes or so before I got back to it. When I started stirring it (since it had sat briefly) before pouring in the bowls, it was a little thinner consistency again!?? It was like a few tablespoons of water had been added to it, or something...does this make sense?? Like it thinned as it sat?!

When I filled my bags, it was immediately running right out the tip....it shouldn't have done that right?? Unless I had thinned it, right?? But I hadn't. I went ahead and used it and it flooded perfectly...but it wouldn't hold the shape of the star or flower tips...a little while after the boys were done with them, I checked on them and the stars and flowers they'd done were just big blobs...lol. I don't know...the only thing I can think of that was different today was the humidity was really high - it started raining about an hour later. It was also on the cool side, though...and I've had all my windows open and only used the screen doors today (left the regular doors open)...so that the house could air out on such a breezy day. Confused! lol Has anyone else experienced this or have any ideas what might have caused it? Good thing it was just for me and the kids to play with and not for an order...lol.

Thanks for all the replies!

It most likely was not grease residue...as I used the same bowl I always do for it...my KA stainless steel mixer bowl...and it had soaked in hot water/soap overnight, was washed in the dishwasher...and then because I planned on making royal with it, I wiped it all down with vinegar - including my paddle. Minus the vinegar, that's how I always clean the bowl/attachments. And I've even made royal before and forgotten to wipe everything down with vinegar beforehand and not had this problem. As for the tips - I always run them through the dishwasher, then soak in vinegar a little bit after every use...just in case the next time I use one of them is with royal. And I always use disposable plastic bags when working with royal to avoid the possibility of any grease residue in the bag. So that pretty much rules the grease option out...lol. But it was doing what it did in the bowl...and I knew my bowl was extra clean, so that's what lead me to wonder if it was the humidity. I bet if I hadn't opened up my windows and doors to let in the fresh air that it would've been fine. I literally could feel the dampness in the air, so I bet that was it...just wonder why it never occurred to me until AFTER I'd made the icing?! lol

Lesson learned: If you live in the crazy humid South...put your house on lock-down before making royal icing!! lol

I know!! lol I'm making IMBC on Thursday for what will likely be the last time until at least November...lol. And even in November, I'll have to wait for a 'not so humid...little bit cooler' kind of day! lol Guess that's what I get for living in the South AND between the beach and a river...I'm just outta luck!

I've actually quoted (sort of) the Wicked Witch of the West many times down here in Dixieland....'It's melting! It's melting!!' lol Bad thing is that I was usually soooo angry and sad that I actually sounded like her! HA! Sometimes I've wished I owned a refrigerated truck that I could take with me to all the parties my cakes have gone to...and set up the cake table IN the truck and make everyone come in there for a slice!! lol