Pistachio Rose Macarons - 4th new recipe of 2012

Pistachio Macarons with Rose Buttercream Filling

Macarons are French cookies, and they're made of two light outer shells sandwiched with a soft filling, usually buttercream.  Here's the recipe I started with.  I made two modifications -- Instead of 2/3 cup of almond flour and 1/3 cup of ground pistachios, I went with half and half.  I didn't have the powdered food coloring that all of these recipes recommend, so I omitted it.  After I piped the shells, I topped them with some of the ground pistachios, because I didn't have rose petals.

I went with a French meringue, where the egg whites and granulated sugar are whipped together, as opposed to an Italian meringue, where a boiling sugar syrup is whipped into the egg whites.  This recipe worked really well, but the batter I used to make another recipe was too wet after I piped them, so I may try the Italian method the next time.

For the shells, you take the ground almonds and ground pistachios and add them to powdered sugar.  I had read a number of recipes that suggest making castor sugar by running it through a food processor.   This yielded a nice, fine powder, and I'll probably do that again.  I also left the powdered pistachios out to dry on a very dry day and used almond flour instead of grinding my own blanched almonds.

Added cream of tartar and granulated sugar when the whites got foamy

Stiff peaks. Ready to fold in the dry ingredients

Folding in the dry ingredients

Piping them onto parchment paper

Once you pipe them, you let them dry out on the parchment or silpat.  I believe the reason for this is that when they dry off on top, the steam from cooking can't bubble out the top and stays in the shells or pushes up on the bottom creating "feet."  This also made it a lot easier to remove them from the sheets. 

I also made the buttercream, following the recipe exactly, and it came out to a perfect piping consistency once it cooled a bit.  I also used egg whites out of a carton for the buttercream, and that didn't seem to hurt the recipe at all.