Wednesday, December 12, 2012

Macaron Making Made Easy! / tips for reproducible and quantifiable macaronage

Hey guys, these past few weeks I decided to tackle another trendy food out there: macarons! A well made macaron has two meringue-based cookies that each have a crunchy exterior with a mildly sweet, soft almond interior, and a rich complementary filling.  Furthermore, the cookies should have a smooth, uncracked shell/crown, no air pockets inside, and feet (the rough ring below the smooth shell).  Fun facts:  Just like how you can order poutine at McDonald's in Canada, in France, McDonald's sells macarons at some branches.  McD's macarons are made by a company owned by Groupe Holder, who also happen to own LadurĂ©e (the original pastry shop that invented the double-decker macaron, now a chain of luxury pastry shops where you can buy macarons at a price of ~$3 a pop).


Left: Raspberry mascarpone macaron, Center: Banana custard macaron, Right: Dragonfruit French buttercream macaron

It is said that the making of macarons is the true test of a French pastry chef.  With only four ingredients, I knew that making this cookie would most likely involve some very specialized technique.  However, when researching the recipes available online, I was shocked by the wide range of methods used.  Some recommended steps, like leaving raw egg whites out for a day in advance, or needing to fold the batter exactly 40 times sounded like voodoo magic to me.  There had to be some way to standardize and quantify this otherwise elusive process.

After compiling about a dozen recipes online, I averaged the amount of each ingredient across the recipes.  Furthermore, I reasoned that even though each recipe had its own nuances, all the recipes must have the same bare essential steps in common.  These are: 1) Beating egg whites with sugar to make a stiff peak meringue, 2) Sifting confectioner’s sugar and almond flourinto the meringue, 3) Macaronage – or the “art” of folding the batter to just the right stage, 4) Piping the batter out and letting it rest, and 5) Baking of the macarons.

Step one: Making Meringue
The only fuss with meringues I saw were that some recipes called for making a simple syrup out of your sugar prior to adding it to your egg whites, and the majority of recipes saying to add sugar slowly during the beating process.  When the goal is to simply create a stiff-peak meringue, neither of these steps are necessary.  The rule ended up following with my meringue was – it’s better to incorporate too much air than too little.  I made my meringue by dumping in all the granulated sugar into the egg whites and mixing with a handmixer until I achieved stiff, glossy peaks (when you remove the handmixer from the meringue, two peaks the stand straight up are formed).  At this point, I added any desired coloring and mixed for an arbitrary additional minute.

Left: Meringue beaten to the point of stiff peaks, when removing handmixer from meringue, a good amount sticks to the beaters. Center: Adding food coloring. Right: Finished and colored meringue with stiff peaks

Step two: Combining Particulates and Meringue
Some recipes were more fussy about needing to sift your confectioner’s sugar and almond flour together 2-3 times prior to adding to the meringue, and ensuring that the two dry ingredients are definitely well-combined.  Some recipes specify that you must ensure that your confectioner’s sugar contains no corn starch, since (gasp!) some brands of confectioner’s sugar are in fact, cut with corn starch.  I took a look at my box of sugar, saw ‘corn starch’ listed as an ingredient, shrugged, and threw it in.  My thoughts were that they are both sugar-based particulates, so a small amount of corn starch probably wouldn’t be a big deal (spoiler: it wasn’t a big deal).  Lacking access to a sifter/food mill and lacking the patience to sit around sifting powder together, I took a simpler approach.  My thoughts were that since Step Three will involve lots of folding of the macaron batter, there shouldn’t be any need to painstakingly combine the sugar and almond flour. The sifting is actually important, since the folding of the batter will not be vigorous enough to break up large lumps of flour or sugar.  To add the particulates (almond flour + confectioner’s sugar) to the meringue, I dumped both together into a colander and shook it above my bowl of meringue until all of the dry ingredients that would pass through had passed through.

Left: Macaron ingredients - almond flour and confectioner's sugar in collander, sugar and egg whites in bowl. Center: my sifting contraption of a collander over the bowl of meringue, with a larger pot to catch spills. Right: Cool pattern of particulates generated from sifting
Step three: Macaronage
Yes, macaronage is the actual French word for the act of making macaron batter.  Every recipe agreed that this is by far the most important stage.  What happens when you combine the particulates and the meringue and do any additional mixing is the air previously incorporated in the meringue is forced out.  If too much air is kept in the batter, then your macarons may develop air pockets and your shells may crack.  If too much air is forced out of the batter, then your shells may collapse.  Recipes varied in their suggestions for reaching this all-important stage, from saying you should wait until it looks “like magma”, or if you drip a bit from your spatula and it re-incorporates in 10 seconds (some recipes said less, some said 20).  All these suggestions are trying to do is find a way of approximating the batter viscosity, so I figured there must be a better way to quantify when a macaron batter is ready.  Without any fancy lab equipment like a viscometer or rheometer, I tried to use some simple, reproducible ways of approximating viscosity and testing the batter at home. 

Left: My first attempt at a technique for measuring batter viscosity, dropping a mentos and timing descent. However, this did not yeild very precise results when dropped in water, honey, and oil.  Center: Another failed attempt at measuring viscosity, mainly since the rate of flow of batter out of the funnel depended in part on the height of the funnel (the batter flowed faster if held low, since a continuous stream was formed). Right: Using a straw to withdraw enough batter to make a single test macaron.
The most valuable test I came up with was to simply use a straw to suck up about ¾ straw’s worth of batter, squeeze the batter out onto a bit of parchment paper, and use that as a test cookie (rather than piping out the whole batch and finding out the batter wasn’t right). The techniques of dropping a small round object into the batter or running the batter through a funnel proved to be either totally not workable or not very precise. What I ended up using to approximate viscosity was a piece of paper (8.5” x 11”) placed on a board and leaned at an incline, producing a 10-5.5-8.35 right triangle.  I placed a tablespoon of the batter onto the paper between the 11” an 10” mark on the paper, raised the paper onto the incline, and timed 60 seconds.  After 60 seconds had elapsed, I lowered the paper and marked how far the batter had travelled.  This allowed me to compare viscosities during the macaronage folding process, and also between batches. 

Once I had found an ideal batter-travel-distance (BTD) corresponding to batter at the correct stage for making macarons, I tried a little experiment.  For my successful batch (the red macarons), I thought the macarons looked flatter than I would’ve liked.  When I looked at the cross section of a macaron with an air-pocket, I thought, “well, maybe the air pocket wouldn’t be there if there were more batter between the base and the shell” – aka, more particulates were needed.  For my subsequent batches, I tried using a quarter cup more of each almond flour and confectioner’s sugar, and again measured the BTD.

Left: A diagram of the tilted-paper batter-travel-distance (BTD) setup.  Right: The two hashmarks on the left were the ideal BTD for 0.75 cups of each almond flour and confectioner's sugar to 2 egg whites' worth of meringue.  The two hashmarks on the right and the batter pictured are the ideal BTD for 1 cup of each almond flour and confectioner's sugar to 2 egg whites' worth of meringue.  The ideal batter using more flour & sugar was significantly more viscous (2.375" inches travelled for low viscosity, 1.625" travelled for high viscosity).

The results – I found that with increased particulates in the batter, the batter was ready to bake at a higher viscosity (also meaning, less mixing was required and presumably more air was retained in the batter).  How could this be?

Left: High particulate concentration, primarily almond flour, prevents air bubble coalescence (purple spheres represent almond flour particles, yellow strands represent protein structure of the meringue, orange hexagons represent dissolved sugar from confectioner's sugar, blue bubbles represent air bubbles incorporated into the meringue, and the blue backdrop represents the water present in the batter from the meringue).  Right: By decreasing the (almond flour+confectioner's sugar) to meringue ratio, air bubbles are allowed to coalesce.  If allowed to bake, these large air bubbles will further coalesce and form air pockets in the macaron.

Well, macaron batter is basically a suspension of particles (almond flour and confectioner’s sugar – although I suppose the sugar may dissolve more than the almond flour) and small air bubbles in liquid (water from the egg whites).  What causes viscosity are the interactions and collisions between the particulate components, so having more almond flour + confectioner’s sugar means a more viscous batter.  Air pockets are formed when the small air bubbles in the batter coalesce.  Since large bubbles are more buoyant than small bubbles, these larger bubbles rise to the top during the baking process, resulting in a large pocket of air directly between the shell and the interior of the finished cookie. However, the viscous interaction between particles in the suspension prevent these bubbles from joining together.  What this translates to is – using a greater proportion of particulates (almond flour+confectioner’s sugar) to meringue means the batter can handle more air, will require less mixing, will be ready to bake at higher viscosity, and will result in taller macarons.  What this also implies is that any two recipes that differ even slightly in particulate-to-meringue proportion will have different ideal batter consistencies or, when two people talk about macaronage and the right consistency, there’s a good chance they’re not even talking about the same thing!

While the BTD test worked well for me, I’m hesitant to recommend it for all readers since I don’t know how reproducible it will be for everyone.  What I can recommend is for you to mix your batter to a stage where it flows off your spatula in continuous ribbons (err on the thicker viscosity side), use a straw to pull off one cookie’s worth of batter, and bake a test cookie.  If the shell cracks or air pockets form, give the batter about 20 more folds and try again.  You can set up your own BTD test once you have batter of the right consistency so that you’ll know about what viscosity to fold to every time.

Step four: Pipe and Rest
At this stage there was a good amount of consensus between recipes.  Use a piping bagto pipe out circles of batter about 1”-1.25” in diameter onto silpat or parchment paper.  Hit the pan flat on a surface a few times to force out any large air bubbles.  If your ideal batter viscosity is high, your batter circles may not flatten out very much on their own, and may have little points.  You can flatten these out by wetting your finger under the faucet and pressing the points down flat.  At this point, let the piped batter sit for upwards for 30 minutes.  This may take as long as over an hour, but I have found this step to be critical.  What you are looking for is for the batter to not stick to your finger or feel moist at all when touched lightly – it should almost have the feel of rubber.  When I ignore this step and put in circles of batter without any rest, even if the batter is the right consistency, I always get cracked or poorly formed shells.  I’ve heard that some others are able to avoid this step, it is possible that there is some combination of meringue composition and oven settings that make it so that the shell dries out on its own in the oven at just the right speed, but I haven’t found it.  

Left: Red macaron batter resting. Left Center: Red macarons after baking. Right Center: Yellow macaron batter resting.  Right: Yellow macarons after baking.  Note the larger height of the yellow macarons, which were made with more almond flour+confectioner's sugar, but with the same amount of meringue.
Step five: Bake
What worked for me was a little over 15 minutes at 300o F,  I’ve seen others use less time and higher temperatures, all the way up to 400o F, although I wouldn’t recommend it.

And you’re done!

Now the fun, and in my opinion, considerably easier part: picking a filling.  For my three, I wanted to have a little diversity and use things people maybe don’t see in macarons so much.  Some filling ideas:

  •         White chocolate mousse (can be flavored with any number of fruit syrups, ex: cherry, raspberry, etc. See my first post, http://mobiusbacon.blogspot.com/2012/10/the-greatest-cupcake-ever-made-honey.html)
  •         Mascarpone & raspberry puree (can be adapted to any fruit, or can use jam as a substitute, blend fruit in blender, sieve out seeds if desired or necessary, and then mix/blend with mascarpone, roughly 1 tbsp of puree to ½ cup mascarpone, with salt to taste)
  •         Chocolate ganache (melt chocolate, mix with butter and/or heavy cream)
  •         Banana Custard (blend banana, egg yolk corn starch, sugar, milk, vanilla, salt and heat on the stove till thickened) can be adapted for oranges, lemons, by instead simmering milk with ~one fruit’s worth of juice and 3-4 fruits’ worth of zest, whisking together eggs and all other ingredients, tempering the eggs with the milk, then adding the eggs to the milk and heating on stove till thickened.
  •        Straight up jam – really any kind of jam, just match the color and you’re good to go
  •         Some iteration of peanut butter – straight up peanut butter or made into a mousse, ganache, or just thick sauce
  •         Dragonfruit French buttercream – (as with mousse or mascarpone, just make the base buttercream and fold in fruit syrup).  With pink dragonfruits, heat pulp on stove, strain through coffee filter overnight, heat collected syrup on stove till reduced by half. Add to this volume the balance in recommended sugar in French buttercream recipe, and heat until dissolved and bubbling.  Temper eggs, then slowly whisk in the all of the syrup.  Let cool to room temperature, then whisk in butter 2 tbsp at a time.
  •         Classic American buttercream – (again, add whatever flavorings you want). Cream ~1 stick butter, add 1.5 cups confectioner’s sugar and whisk until combined, add vanilla, salt, and other flavorings to taste.
  •         Thai tea buttercream – make a concentrated batch of thai tea (bring 1 cup water to a boil with 2 pods star anise, add 4 bags black tea, let steep for 30 minutes so that flavor is extra concentrated, stir in 1 tbsp sugar).  Fold in 2-3 tbsp into a batch of either French or American buttercream as described below. Note: haven’t tried this, this is just speculative.

I bolded the ones that I actually used in my pictures.  Red had mascarpone+raspberry jam, yellow had banana custard, and purple had dragonfruit French buttercream.


Left: Egg yolks beaten till frothy/lightened in color. Left Center: Egg yolks beaten with dragonfruit syrup. Right Center: Softened butter beaten into yolk/syrup mixture. Right: Finished dragonfruit French buttercream.  Note: I thought the flavor was a bit strong, so I used a fair amount of vanilla extract and mixed just part of this with a batch of unflavored buttercream before spreading on my macarons.
Some helpful troubleshooting resources:
http://foodnouveau.com/2011/12/16/destinations/europe/france/a-macaron-troubleshooting-guide-useful-tips-and-advice-to-master-the-french-delicacy/

http://bravetart.com/blog/MacaronMyths

For the recipes, check out the links on the side of the page to learn how to make french macarons filled with raspberry mascarponebanana custard, or dragonfruit buttercream filling!