Sunday, January 13, 2008

Paean to Swiss meringue

Meringue is a fascinating application of biochemical principles. Whipping weakens the hydrogen bonds that keep amino acid chains in compact globular forms, causing them to unfold. The strands of amino acids then form a lattice around the bubbles of air and allow water to arrange in a more orderly fashion. This gives the whites a stiff but shapeable consistency.

My favourite, Swiss meringue, is made by heating egg whites and sugar over a bain-marie to a temperature of 160°F and then whipping the mixture using a stand mixer for about 5 to 10 minutes until the whisk holds a bec d'oiseau (bird's beak) when lifted. This indicates that the proper stiffness has been reached:


Swiss meringue is stable because the eggs are partly cooked which holds the albumin amino acids in their unfolded state. Unlike French meringue, which is the simple beating of sugar and whites together, the Swiss foam structure is more stable and not prone to weeping. Weeping occurs when the amino acids refold thereby releasing water that was previously orderly arranged around the unfolded amino acids. This is a handy tip for making toppings: switch to Swiss and that meringue pie will not seep water.

Also, Swiss is less fussy than Italian meringue, which is made by adding hot, boiled sugar syrup to beaten whites. There is something contrived, in my opinion, when something as simple as meringue begins to demand a candy thermometer, impeccable coincident timing (you will need to have soft-stiff beaten whites by the time the sugar syrup reaches 240°F) and a level of dexterity to safely pour the syrup in a thin but steady stream into the whipping stand mixer. For all this effort, it is still debatable whether the whites reach the required pasteurization temperature of 160°F because much of the heat of the syrup is lost to the bowl.


All three meringues can be piped into different shapes, such as mushrooms for bûches de Noël as shown in the preceding photo. The type of meringue to use is not so much an issue for baked-through confections - French will suffice though Italian and Swiss are more pliant.

I first discovered Swiss meringue when I made Martha's birthday cake for Patrick. It piped very easily and looked spectacular after being torched. Recently, I used this frosting for our anniversary cake but this time eschewing the use of a pastry bag. I merely swirled the airy mass around the sides then up top, then torched the circular ridges left by my spatula.


Probably the best application is Swiss meringue buttercream (SMBC). Easy, endlessly adaptable, and decidedly grown-up (yet good with kids), SMBC is my favourite icing. It is also rich and decadent so only a small amount is needed when frosting, otherwise the cake may become too cloying.

Many are put-off by the curdling that occurs at some point when butter is mixed into the meringue. As I have written in a couple posts, this is not fatal. More whipping at a higher speed for perhaps another three minutes (maybe longer or shorter) will consistently bring the mixture to a silky smooth consistency. Please refer to the discussion mid-way through this post and the video towards the end of this entry.

SMBC can be frozen for a couple months. I make sure it reaches room temperature before I whipping it smooth or pulsing it through a food processor so that it does not become grainy (this situation would be a mistake, and one that may be difficult to remedy). The latter method produces a buttercream the consistency of mayonnaise. My left-over chocolate SMBC from December was processed this way and used on a small cake which I then complemented with a handful of raspberries. This is shown on the photo below. Also shown is SMBC flavoured with mango purée, which results in a textured frosting that is ideal for a homey approach to cake decorating. Click over the photo to enlarge.


Notes:

Oil and fats are the enemies of meringue. The slightest bit anywhere (bowl, beaters, hands) will mean that the meringue will not form. There is fat in yolks, so there must not be a trace of it. Once, I couldn't figure out why my meringues would not form - it turns out that my silicone whisk was to blame. Silicone and plastic utensils can have oil residues on them that are hard to wash off.

To make Swiss meringue, combine 1 cup of granulated sugar and 4 egg whites in a scrupulously cleaned bowl of a Kitchen Aid mixer. Whisk continuously over a bain-marie for 3½ to 5 minutes - until an instant read thermometer registers 160°F. Transfer the bowl immediately to the stand mixer and whip at high for 5 to 10 minutes until a bec d'oiseau can be formed when the whisk is lifted.

If pasteurized liquid egg whites are used, you will only need to whisk over the bain-marie until the mixture is hot to touch and the sugar has completely dissolved.

For the longest time, I couldn't get my meringues to dry completely. It turns out that a generous dusting of confectioner's sugar before the meringues go in the oven helps a lot.

On the history of meringues, European cooks in medieval times created egg white foams by beating it with a stick, however it wasn't until the 1600s that the first documented confections of egg whites with sugar was published (D. Muster). Then in 1720, the Swiss pastry cook Gasparini "invented" meringues as we know it (P. Montagné, Larousse Gastronomique, 1988). Another couple centuries later, came the most famous incarnation of meringues - the pavlova.

11 comments:

glamah16 said...

Very informative. I how you saw a eagle in whipped eggwhites. How cool is that!

Rosa's Yummy Yums said...

Thanks for the great and informative post! Your meringue looks gorgeous!

Cheers,

Rosa

Julie said...

Great post, Julius!

I failed the first couple of times I tried baking a pavlova, but once I got it, it was wonderful--a great dessert!

Aparna said...

New to your blog. Lovely and informative write-up.
You are very creative. Liked the bird in the meringue peaks!!!

Janet said...

Hi Julius,
Robb and I were talking about writing up something regarding the different meringues this month, too. It will not be possible to top what you have done- what a really good job!
I think perhaps we will discuss the brown sugar Italian meringue that I favor for pies and baked Alaska, etc.
Janet of Bake Through

Shannon said...

Hello Julius,

In the last few months, you may remember receiving an email invitation to become a part of the Foodbuzz Featured Publisher Program. With all the recipe-writing and food photography to be completed, we know emails can easily get lost in the shuffle, so Foodbuzz would like to re-extend our offer of inviting you to be a part of our food blogger network. I would love to send you more details about the program, so if you are interested, please email me at Shannon@foodbuzz.com

Cheers!

Shannon Eliot
Editorial Assistant, Foodbuzz.com
shannon@foodbuzz.com

chou said...

Julius,
You make my heart weep. With joy. :) Great explanation--so when are you going to join us food science grad students?

Ann said...

Wonderful tutorial!

The Food Librarian said...

Julius, I completely agree that the Swiss is so much easier! In fact, I'm terrified of Italian...I'm so clumsy that I know I'll fling that hot syrup all over the kitchen and my skin! Thanks for great photos, inspiration and lots of yum on your blog.

ioyces said...

Julius!! Your blog is so informative!! Wow!! I am in awe!! Fantastic pictures too!! Love the 'birds'!! :D

Karen said...

WOW, just Wow! Very impressive! Thanks for this post.