If you read much of my online dribble, you’ll notice I talk about butter temperature.  A lot.  The temperature of your butter effects everything.  I swear.

Recently I got into an online debate with someone about how warm butter should be when making Swiss meringue buttercream (SMBC).  To recap, when I make my SMBC I take my butter out the night before and make sure it’s room temperature.  I also say to dump it all into your bowl at one time (if your bowl can handle it) and mix on LOW.  As was pointed out to me, my method is contrary to several very famous cake artists and pastry chefs.  Toba Garrett’s very famous recipe says ” the butter should be slightly moist on the outside but cold inside”.  Ben Ron-Israel’s recipe says “butter, softened”, which means the butter should be cold enough to pick up with your fingers, then to add it in pieces.  Both say to mix on medium high.

If you have ever made this type of buttercream you’ll notice the finished product almost always has air pockets in it.  Nobody really talks about them for the home cook, but those pesky air pockets are hard to get out of the buttercream.  It does not go onto a cake smooth and leaves pock marks that you have to fill in if you want a professional finish.  Air pockets are one of those things that get worse the more you try to mess with them, too.  There are a few ways to deal with them, you can smooth your cake as best as you can, let the buttercream firm up in the fridge/freezer then fill them in one by one, or you can take your bowl of buttercream and hold it over warm water to raise the temperature by a few degrees while stirring and it’ll get rid of them.  But you also can melt your buttercream, which sucks.

Believe me, I know how it looks and sounds when some crackpot blogger says to do something totally different from these very famous, very well respected, super awesome cake artists whom I also worship.  I did it their way for a long time, and I’ve spent my fair share of time filling in pock marks and melting buttercream over water.  I just accepted it as part of how these things are done. But one day, I was making some SMBC and had a pound of butter on the counter that had been sitting out overnight.  It was nice and soft.  On a whim, I used it.  I was adding a bit at a time using a spatula because it was too soft to pick up and had my mixer on medium high, but 1/2 way there I turned my mixer onto low (so nothing would slosh out of the bowl) and chucked the rest in because, well, I’m impatient and was in a hurry.  To my surprise, 5 minutes later I had the smoothest buttercream I had ever made.  The next time I made a batch I tested my new theory… I used soft butter that had been taken out the night before, I had my mixer on low and I threw the whole pound in.  Again I got super smooth, super silky SMBC with very few, if any, air pockets.

Some have argued that my location makes this method possible since I don’t deal with high heat in San Francisco.  This is true, but neither do you if you live in an area where it gets hot outside.  You have air conditioning.  I know you do.  If you don’t have air conditioning and it gets 100 degrees in your city, do yourself a favor and move.  Dude, that’s just unlivable, man! Why put yourself through that when I know the rest of your city has air conditioning?  😀  Seriously though, I assume your home kitchen is in the low 70’s, which is fine for buttercream making.  If it’s warmer then that you are going to have problems making any buttercream, not just Swiss meringue.

Some have argued that my location makes this method possible because I don’t deal with high humidity.  So I started paying attention to Weather.com to see how humid it gets in San Francisco.  To my surprise, I DO in fact live in very high humidity.  San Francisco is a 7×7 square land mass surrounded on 3 sides by water and covered by a constant marine layer and fog… 90% of the year. Our humidity never dips below 60% and averages around 75% with a very low dew point (it’s 78% right now).  Which means it’s humid.  Granted, it’s not 100 degrees so most people don’t notice how humid it is, but it’s just as humid as the East Coast or Florida.  Weather.com measures humidity exactly the same all over the world so, no New York, you don’t have “special” water making it more “wet” then California.  The measure of humidity in San Francisco is the SAME measure of humidity as, say, Tampa Bay, FL (which by the way, at the time of writing this has humidity at 49%.  Just sayin).

Because there have been a few people in different parts of the world that have had a hard time making any SMBC recipe, out of curiosity I made a batch of my SMBC documenting temperatures and humidity/dew point at the time I made it.  I’d love to get to the bottom of why it works here and maybe doesn’t work there, and the only way to do that is to document the exact conditions I work in.

Outside: 59 degrees, Humidity, 84%, Dew Point 54 degrees. Yes, in July.

Tools used for this experiment:  My super cool Rubik’s Cube clock/alarm/thermometer/calendar I got from Think Geek which is shockingly accurate, and a meat/oven thermometer I got form Sur La Table.

Room Temperature: 70.8 degrees, Butter Temperature, 70 degrees. Disregard the "oven temperature" reading, as it is measuring my oven temperature.

Meringue Temperature: 83 degrees, cool to the touch.

Finished Buttercream: 75 degrees.

Notice my awesome texture?  No?  Well here’s a close up!

At 75 degrees, this buttercream is perfect for me to put on a cake or pipe onto cupcakes with very few air pockets.  So, if you are still having problems, let me know the conditions of where you are, maybe we can get to the bottom of this together!