Tuesday, November 18, 2014

Improved sweet potato & marshmallow casserole! / Sweet potato souffle with sour cream marshmallow, scallion, and roasted garlic

Sweet potato souffle with scallion and roasted garlic, topped with toasted sour cream marshmallow
Most Thanksgivings, I like to try and put an updated spin on classic dishes.   This year, I decided to tackle what I think is the worst of all traditional Thanksgiving dishes, sweet potatoes and marshmallow casserole.  Personally, I think this composition doesn’t make much sense, since it pairs sweet with more sweet, and is served as a appetizer/side, rather than a dessert type dish.  I decided to update this dish by making the pairing more like something that hopefully we can all agree makes more sense – a loaded baked potato.  Follow these links to skip to just the recipes for sour cream marshmallows and for sweet potato soufflé.

Rather than pairing the sweet potato with sweet marshmallows, I decided a savory appetizer would require a savory marshmallow.  For a baked potato-inspired dish, it would make sense to have the marshamllows be sour cream flavored.  Making savory marshmallows really is as simple as mixing in a few tablespoons of a savory flavoring component into the mix of a normal marshmallow recipe.  However, in the course of this project I also discovered a way to make the procedure for making marshmallows significantly safer and faster.

Left: corn syrup mixed with sugar to ~85% by weight sugar. Center: blooming gelatin. Right: mixed sugar solution and dissolved gelatin, with sour cream
Left and center: sour cream marshmallow mixture after 10 minutes whipping, coated with corn starch and powdered sugar. Right: squares of sour creammarshmallow cut out
The traditional recipe for making marshmallows involves 1) blooming gelatin, 2) bringing a corn syrup/sugar syrup to 240 degrees Fahrenheit, 3) carefully adding the super-hot syrup to the gelatin in a stand mixer and whipping for up to 15 minutes, and 4) cooling and cutting the marshmallow mixture.  After analyzing a number of marshmallow recipes, I found it odd that all required the second step of heating sugar syrups to a set temperature (typically necessary in confection making in order to reach a precise/consistent sugar concentration, in this case, ~85% sugar by weight), but some recipes added this sugar syrup to unmeasured or unspecified amounts of water used for gelatin blooming in step 1.  This suggests that while having a low water content in marshmallows is important, a range of water content would produce acceptable marshmallows.  Since the step for heating syrups was clearly not very important for acquiring precise sugar concentrations, the only other purposes working with a heated syrup would serve would be 1) ease of dealing with a slightly lower viscosity fluid, and 2) heat from the syrup would aid in dissolving gelatin.  Ultimately, I found that the traditional step of heating sugar syrups to 240F could be eliminated by calculating and preparing a sugar solution of desired final concentration (85% sugar by weight), and applying low level heat to dissolve gelatin separately.  The 85% sugar solution and dissolved gelatin could be mixed with flavorings (sour cream in this case), whipped, cut, and cooled just as in traditional recipes.  This modification to the traditional procedure eliminates the time needed to heat the sugar syrup, and eliminates risk of splashing extremely hot, skin-burning syrup around your kitchen.
Left two: Roasted sweet potato blended with green onion, roasted garlic, brown sugar and butter. Center: Making a roux for bechamel sauce.  Right two: Finished bechamel sauce
Leftmost: Combining sweet potato blend and bechamel sauce.  Center-left: Stiff-peak meringue. Center-right: souffle mix in ramekin. Rightmost: Finished sweet potato souffle with green onion and roasted garlic
As opposed to the traditionally dense sweet potato mash in a sweet potato and marshmallow casserole, I thought the dish could benefit from some added variety of flavor and lightness.  For this reason, I thought a great accompaniment to the sour cream marshmallows would be a sweet potato soufflé.  For this, I basically used a scaled down version of Emeril Lagasse’s recipe, with one clove of roasted garlic and a tablespoon of finely chopped green onions mixed into the sweet potato puree.  Once removed from the oven, these soufflés can be topped with the savory marshmallows and torched for even more complex caramelized flavor.  Enjoy, and happy Thanksgiving! 

Another view of the savory sweet potato souffle with toasted sour cream marshmallow

Thursday, November 6, 2014

Halloumi cheese waffle and poached pear / Broader waffle maker applications part 1!

It’s been another few months without articles, but more will be coming soon! I’ve been busy recently with my PhD thesis proposal (it went fine, btw).  In the next couple articles, I’ll be investigating interesting applications of a heavily underrated piece of kitchen equipment – the wafflemaker!

Left: Halloumi cheese waffle. Center: Poached pears marinating/macerating in a wine syrup. Right: Poached pear with gelato and (unpictured) halloumi cheese waffle

The unique advantage of a waffle geometry is its increased surface area to volume ratio, compared to a flat square or circle of similar dimensions.  The Good Eats episode about waffles does a good job of discussing some of the advantages that come from this property, for instance, waffle irons were used to mold the first soles of running shoes (the beginning of Nike).  For regular edible waffles, the unique benefits are the ability to retain wells of syrup and to have lots of fried crunchy/crisp exterior, with some soft interior.  These seem like properties that could easily extend to many other fried goods, wouldn’t you think?
Fried halloumi cheese slices - very crispy, but little chewy/soft interior.  If cut into cubes, they require 5 manipulations to fry each side

One of the first foods I thought could benefit from wafflization was halloumi cheese.  Halloumi cheese is a special type of brined cheese, salty like feta but softer and creamier, that is known for its ability to be fried or grilled and retain its shape while gaining a crispy exterior.
Left: Comparison of percent by weight of fat, protein, and water (the remaining weight out of 100g that was not fat or protein) between 5 cheeses categorized as high melting point and 5 cheese categorized as low melting point.  No significant differences in composition were observed.  Right: Comparison of salt content between high melting point and low melting point cheeses in 100g of cheese.  The difference was found to be significant at p<0.01 using 1-way ANOVA.

I’ve seen many peoples’ websites attempt to explain why this is the case, but have come across a surprising range of explanations.  While many of these reasons (moisture content, protein content, type of fat, salt content) all seem to be plausible reasons, when analyzing the composition of several high-melt point (halloumi, feta, parmesan, cotija, and aged asiago) and low-melt point cheeses (mozzarella, swiss, cheddar, camembert, and brie), I found that only salt content seemed to significantly contribute to the melt-point (data courtesy of http://www.sargentofoodservice.com/trends-innovation/cheese-melt-meter/ and www.fatsecret.com, acid-curdled, reduced fat, and added fungal culture cheese excluded from analysis, n=5 for each, P<0.01 for salt content).  Salt molecules present within a cheese are believed to interact with the cheese protein network – with more salt keeping these networks stable when they would normally fall apart due to applied heat.  Therefore, I believe that the interesting properties of halloumi are due to its relatively high salt content from brining.

Left: 1/4-1/2" slice of halloumi on medium heat in waffle maker.  A crispier exterior is attainable by brushing with oil and/or using higher heat.  Center: After 2 minutes or less, the halloumi cheese gains a crisp exterior.  Right: The interior of the halloumi cheese waffle is airy, soft and light due to small air pockets in the cheese.

By brushing, dipping, or coating with oil, a much crispier exterior than what I have pictured here is possible.  Frying in a waffle maker requires as little as 2 minutes (depending on your settings), without the need to turn halloumi cubes 5 times (for all sides of a cube), and yields a crispy on the outside, light and airy on the inside cheese waffle.  I didn’t think of this till later, but it would also go well with a nice poached pear.

Friday, May 30, 2014

Variations on xiao long bao (Soup Dumplings) / Vegetarian xiao long bao with carrot-ginger soup and samosa filling

It's been a while since my last post, I've been a bit busier and also took a while to think of a new project.  I decided to try making xiao long bao (XLB), or Chinese soup dumplings.  These tasty dumplings are usually filled with a ground pork/scallion filling as well as a rich broth.  What's interesting about the process of making XLB is that it uses gelatin to set the broth into a solid state, which can be easily handled and used to fill the dumpling.  This same technique has been used in a range of other recipes and in restaurants to make liquid-filled ravioli (like the Black Truffle Explosion at Alinea).  Given how versatile/adaptable the process for making XLB is, I was surprised that there haven't been many varieties of XLB produced.  To demonstrate the flexibility of this procedure, I decided to make a vegetarian xiao long bao with a samosa filling (curry potato and pea) with a complementary carrot-ginger soup.


Left: Carrots and onions for boiling in a pot. Center: Softened carrots pureed with immersion blender, cream and ginger powder added. Right: Carrot ginger soup gel after Vegan Jel added to 2X diluted soup, 

In order to create a soup gel, I used the "Vegan Jel" product by Natural Desserts, which is created from vegetable gum.  I chose this as opposed to other vegetarian gelling agents (which you can read about here) because it's substitution for gelatin in recipes was fairly straightforward (1.5 tsp substitutes for 1 tsp gelatin), and because it was claimed to have a similar melting point to gelatin.  In making the soup gel, I found that I had to first cook the soup down to my desired consistency, then dilute it with one equal part of water.  Without this step, the soup dries up during the dumpling steaming step, since a fair amount of moisture is lost.

Left: Mashed boiled potato. Center: Mashed potato with garam masala, coriander powder and cardamom powder. Right: Curried potato filling fried in a pan with onion and mixed with peas
Several recipes for making samosa filling involved cooking down onions with garam masala, then mixing in mashed/boiled potato.  I found that you get much more control over the flavor by splitting your mashed/boiled potato into two batches - to one which you add garam masala, corriander powder, cardamom powder and salt to to taste, the other unseasoned batch you reserve for correcting mistakes (can mix in if any one flavor seems too strong and then adjust seasoning again).  For more texture, it was better to leave some larger not-fully-cooked chunks of potato.

Left: Filling a handmade dumpling skin with gelled soup and samosa filling. Right: pleated and filled xiao long bao 
With a 2X diluted and gelled soup, I found that the ideal ratio of soup:filling was close to 2:1.  At around 1:1 or less, there wouldn't really be a noticeable amount of soup in the dumpling.

Left: Vegetarian samosa filling and carrot-ginger soup xiao long bao steamed for 10 minutes. Right: Opened XLB
I may add more analysis later on gelling agents and an actual recipe entry.  I would say that the finished product was tasty, although could use some improvement.  A meat-filled dumpling typically has more bite/texture, whereas between the samosa filling, dumpling skin, and soup, there isn't much variety in texture.  A future project may be a soup-filled samosa, which would have the needed deep-fried crunch.  Another possibility would be to have a mushroom-based filling for more bite, and a gelled mushroom or vegetable broth.

Thursday, March 6, 2014

The Greatest Cupcake II / Chocolate cupcake with white chocolate, cherry & moscato mousse, spun sugar


I've been thinking for a while now that my last cupcake article was not so visually impressive.  I feel like the blog has come a ways since then, so at the very least I could make a better looking (and hopefully better tasting!) cupcake than before.  Also, I thought it would be fun to decorate cupcakes with my girlfriend on Valentine's, so I focused on preparing components that would definitely have an impressive visual factor and incorporate some of her favorite things.

In the previous cupcake article, I had tried to make a white chocolate cherry mousse, but have to admit it didn't really have the appearance, texture, or flavor I wanted.  With a bit more know-how, I wanted to give it another try.  I was also tempted to buy a whippet/whipped cream dispenser, but couldn't really justify the expense - while they make mousse-making extremely fast and easy, most interesting things that can be done with a whipped cream dispenser can be done without one with just more time and effort.  Maybe in another article.
White chocolate mousse

The construction:

Devil's food cake again for the base.
White chocolate mousse made like before, but I've learned now that to avoid lumps in the mousse, just lightly heat the chocolate/butter or chocolate/egg mixture after mixing
Black cherry moscato syrup made by taking ~3 cups fresh cherries and heating on high heat with 1/2 cup sugar, 1-1/4 cup moscato.  After the cherries had all softened (~20 minutes), the mixture was pressed through a strainer and reduced further, with 1 tbsp moscato mixed with 2 tsp cornstarch added at the end for more thickness and more flavor.  The finished syrup was kept separate from the mousse to preserve its color - mixing it in too thoroughly can result in an unappetizing very pale pink color.
Spun sugar made by heating 6/10 cup sugar with 1 tbsp water and 1 tsp moscato until an amber color was reached (probably corresponding to the "hard crack" stage or beyond, given that some caramelization has occured).  Once the syrup flowed off a fork/chopsticks in thin ribbons, it would be quickly crisscrossed over an egg brushed with oil - an egg for a nice ellipsoid shape, and oil to help remove the hardened sugar cage.  If you decide to try this out on your own, be careful of burns!

Left: an especially fine sugar cage. Center: crisscrossing syrup over an egg on parchment paper.  Right: a collection o spun cages, thicker ones transported a bit better


Friday, January 10, 2014

Foolproof, enhanced, scalable beef Wellington recipe / Deep fried beef Wellington!

Deep-fried beef Wellington
Beef Wellington is notorious for being one of the most difficult dishes for a home cook to attempt. It consists of a beef tenderloin (or filet mignon) wrapped in puff pastry, with optional fillings like mushroom duxelle (dried mushroom spread), pate, prosciutto, or crepes, pretty much a fancy man's hot pocket.  The considerable difficulty lies in:
  • making puff pastry (which can be avoided by using less-tasty pre-made frozen puff pastry), 
  • constructing the wellington to prevent soggy crust (despite recipe suggestions to add prosciutto or crepes, the underside seems to inevitably become soggy or crushed during the prolonged baking period)
  • timing the cooking such that the beef tenderloin and puff pastry are done at the same time.
To address the difficulty in cooking time and crust construction, I decided to take a new approach.

I've had this idea ever since my cronut article to look at more interesting applications of deep fried puff pastry.  Deep frying would be beneficial since
  • the entire Wellington is cooked homogeneously and rapidly, preventing any liquid buildup on a bottom crust
  • the beef tenderloin could be cooked separately and well in advance to its desired temperature before construction of the Wellington, due to the rapid cooking time
  • individual-size or mini beef Wellingtons could be made with a finished crust and beef anywhere from rare to well-done, another added benefit of rapid cooking time
Top left: MATLAB PDEtool simulation of a fried cronut, using the same parameters as found in the ABAQUS simulation in the cronut article, for validation.  The internal temperatures (in Kelvin) are similar.  Top right: model of a beef Wellington fried at 370 degrees Fahrenheit for 4 minutes.  Thermal parameters for puff pastry were identical to those used for croissant dough in cronut model.  Beef and oil thermal properties from Advances in Deep-Fat Frying of Foods, edited by S Sahin, SG Sumnu 2009 on Google e-books.  Bottom left & right: view along the x- and y-axes respectively of the top-right figure.  The puff pastry was modeled to be 1 cm in thickness, beyond that the meat's temperature does not rise above ~150 degrees Fahrenheit, while the puff pastry has all reached temperatures over 150, which corresponded to 'done' in the cronut experiment.
First, I wanted to model the cooking process to make sure I didn't waste a whole bunch of time and money.  Using MATLAB PDEtool, I was able to determine that 4 minutes of frying should be sufficient to cook the puff pastry crust without substantially changing the done-ness of the beef interior.

Left: Seared beef tenderloin. Center; Beef tenderloin roasted at 450 degrees to an internal temperature of 125.  Instead of an expected 10 degree increase in carryover, this cut only reached a maximum temperature of about 130, or on the rare side of medium-rare.  Right: wrapping beef tenderloin, coated in dijon mustard, with mushroom duxelle and prosciutto
I proceeded to sear then roast a cut of beef tenderloin to an internal temperature of ~130 degrees Fahrenheit, for medium rare, on the rare side.  The beef was then wrapped in a baby portobello mushroom duxelle and prosciutto.

Left: Wrapped beef tenderloin, normally this is done with plastic wrap, but I didn't have any so I used a cut up shopping bag.  Center: Wrapping a chilled and wrapped beef tenderloin with an eggwashed layer of puff pastry.  Right: Eggwashed beef Wellington.  The scoring is not advised if deep-frying. 
The wrapped tenderloin was then encased in an eggwashed layer of puff pastry.  This was deep fried at ~370 degrees Fahrenheit for 4 minutes, rotating halfway through. (CAUTION: use protective eyewear and gloves when deep frying something of this size, be very careful sliding the wellington into hot oil to avoid splashing).  The crust came out crisp and flaky, while the interior remained medium-rare.  Served with roasted Brussels sprouts and a parsnip puree.

Left: Beef Wellington deep fried at 370 degrees Fahrenheit for 4 minutes total, rotating halfway through.  Center: Finished deep fried beef Wellington, resting for 10 minutes is sufficient.  Right: Sliced beef Wellington with roasted Brussels sprouts and parsnip puree.  The interior of the Wellington is seen to be still medium-rare, on the rare side.
To confirm that mini wellingtons could be made, I cooked some tenderloin scraps to medium, wrapped them in puff pastry, and fried them as well.  The interior remained medium.

Left: A tenderloin scrap, cooked to medium.  Center: Tenderloin scrap wrapped in puff pastry and fried 4 minutes at 370 degrees.  Right: Sliced mini beef Wellington, still medium with done and flaky crust
By comparison, the baked beef wellington came out at approximately the same done-ness, but requires a good half hour or more resting to not lose a lot of its juices, and to cool down enough to eat.  Also, the bottom crust was tasty, but crushed and not flaky.

Left: Baked beef Wellington. Right: Sliced traditional beef Wellington after only 10 minutes resting, clearly lots of juices were lost, and it was very hot to handle.  The bottom crust is seen to be soggy and crushed, despite the use of prosciutto and a fairly dry mushroom duxelle.  

Tuesday, November 26, 2013

Mushroom pot pie, a quick, easy, vegetarian friendly Thanksgiving dish / Masterchef audition

Mushroom and leek pot pie with roasted red pepper sauce, goat cheese, and fried thyme
Hey everyone, so each year for Thanksgiving I like to cook for a small group of friends & find a new dish to challenge myself.  This year, we were going to have some vegetarian guests, so I got real excited thinking about ways to make the greatest vegetarian Thanksgiving dishes.

For one of these dishes, I chose one that could incorporate some of what I believe to be the best and richest vegetarian dish components: puff pastry, mushrooms (all sorts, truffles included), goat cheese, and eggs.  Out of the many many iterations of puff pastry-based dishes (strudels, wellingtons, tarts...), I decided to go with pot pies, which seemed to fit the rusticity that goes with the spirit of Thanksgiving.

The great thing about pot pies, besides the flavors of the filling, rich gravy, and buttery pastry, is that they can be prepared well in advance of the intended meal.  In these pictures, I had actually pre-cooked my mushrooms, leeks (green onions), and gravy about 2 days before I actually made the pot pie.  For my non-vegetarian friendly version, I mixed in some leftover rabbit that I had braised in beer, soy sauce, and sugar (leftover meats of really any kind go great into pot pies) to make an equally great rabbit, mushroom and leek pot pie.  After preparing all your components in advance, all that's left to do is make a simple puff pastry (modified slightly from Alton Brown) and whatever accompaniments you'd like (see my recipe pages to the right for more detail).
Left: Preparing puff pastry. Middle left: Making a vegetarian gravy with roux and vegetable broth, testing the consistency to see if it's "nape".  Middle right: Making a roast pepper sauce.  Right: Fried mushroom and green onions
As you hopefully noticed, the presentation of the dish is a bit better than usual.  This is due in part to my recent experience at this year's Masterchef auditions.  I went to the open casting call in NY, and brought materials to assemble the steamed bun trio and the beer pastry cream cronut AKA "bronut".  After hours of waiting in line, doing some filming in Times Square for a TV promo, and some more waiting in lines, I finally reached a room with some 20-30 other hopefuls presenting dishes to one or two judges.  My presentation was markedly worse than all the competitors in the room, but I was lucky enough to be selected to move on past the first round.  However, past that point the judges were only interested in personality, and I got beat out by some girl who had 20 pet chickens.  Ah well, I have a whole year to learn how to be bizarro enough for TV.  Below is a T-shirt I made specifically for the audition, but some of my friends liked the design and wanted ones too, so I set up a cafepress storefront.  Check it out if you want your own (alternatively, wait for a sale & just search "haters etc etc" on the cafepress main site)!

T shirt I made for my Masterchef audition.  Check out my cafepress store if you want one too! OR wait for a sale & search "haters etc etc" on the cafepress main site



Tuesday, October 8, 2013

The formula for a longer-lasting soufflé / taro, Thai tea, and green tea soufflés

Lemon soufflé with candied lemon peel
Hey all, I know it's been a while since my last post.  This recent project took a few unexpected turns.  Anyways, I decided this time to focus on soufflés, which are known to be one of the more intimidating baked goods to make.  This reputation was earned in part due to the idea that soufflés will readily collapse, surely ruining whatever dinner party you had planned.  I'm writing this article to hopefully encourage you to give soufflés a chance, as they are a highly versatile and delicious dessert with surprisingly simple execution.
Left: pastry cream, center-left: pastry cream combined with melted chocolate and cocoa powder, with 1/3 of the meringue to be mixed in. Center-right: folding in remaining meringue into pastry cream mixture, right: baked chocolate soufflé
Soufflés have essentially three components, 1) pastry cream, combined with 2) a flavoring element, with 3) a meringue folded in.  This makes the finished product basically a baked pudding, but with the added meringue component allows the soufflé to expand with heat.   My key goals with this dessert were to 1) find a generalizable formula for soufflés that could be customized for whatever flavor desired, and 2) find a way to keep soufflés standing.

A summary of findings and procedure:

  1. create a batch of pastry cream 
  2. choose flavorings low in water content, like powdered drink mixes or alcohol based flavorings, and mix into pastry cream
  3. follow the per-ramekin formula provided below for proportions of pastry cream, flavorings, and meringue
  4. stir 1/3 of meringue into pastry cream mixture, then fold in of the rest
  5. fill ramekins coated with butter and sugar with soufflé batter to the top, scrape a knife over the top to flatten the batter, tap the ramekin against the counter to release any large air bubbles, and run a fingernail along the ramekin edge to create a lip between the edge of the batter and ramekin
  6. bake at ~390 degrees Fahrenheit for 20 minutes

  • in the absence of a working oven, soufflés can be cooked in a rice cooker by loading ramekins in, filling water up halfway, and cooking for ~25 minutes, with slightly inferior texture
  • to a point, higher temperatures and longer cooking times improve soufflé stability
  • lemon juice is known to stabilize meringues, and likewise seems to have an effect stabilizing soufflés, a small amount can be used per ramekin, 0.5-1 tbsp, but will alter the soufflé flavor.  cream of tartar may achieve a similar effect
A generalizable soufflé formula
Creating  raspberry and blueberry fruit flavorings by simmering with sugar and straining to create purees.  Left: boiling lemon peels in first water 2-3 times before boiling in a simple syrup.
I noticed that if I took Gordon Ramsay's chocolate souffle recipe and switched out the flavoring components by volume for fruit puree, the result was delicious, but messy and undercooked.  The obvious cause of this is water content: the flavoring components of a chocolate souffle (chocolate and cocoa powder) each have fairly low water content, while fruit purees have a larger amount of water by volume.  Water as a high specific heat, and must be heated up and vaporized for the protein matrix of the soufflé to set, however, in the meantime all that water is basically boiling the soufflé batter and spilling it all over the place (see above figure).  The key to a generalizable soufflé recipe is then choosing flavoring components with minimal water content.  
Left: combined pastry cream and fruit purees.  Center: soufflé batters added to ramekins coated with butter and sugar.  Right: messy, finished soufflés.  The water content and amount of the fruit flavorings were too high, this can be remedied most easily by using fruit-flavored alcohols or powders for flavor, or  using very small quantities of fruit purees.
I chose to demonstrate this using some of my favorite bubble tea flavors: taro, green tea, and Thai tea, which are each available in flavored powder forms (for green tea, don't make the mistake I did and use real 100% green tea powder, which will end up too bitter and hygroscopic - use the green tea powder mix).  This same strategy can be seen in various other soufflé recipes that call for the use of alcohol for flavoring, since alcohol evaporates much more readily than water.

Left: combining pastry cream with taro puree and taro powder, thai tea powder, and green tea powder mix. Center: ramekins filled with batter prior to baking. Right: Finished taro, thai tea, and green tea souffles.  Note: incorporating 1 tbsp of taro puree per ramekin adds considerable richness and texture to the soufflé.  I highly recommend this flavor.  For green tea, do not use 100% green tea as I did, use green tea powder mix

Formula for a single-ramekin soufflé
1/2 cup pastry cream + 2 tbsp low-water content flavoring + 1-1 1/3 large egg whites (with 1 tbsp sugar) worth of meringue.

A longer-standing soufflé
Experimenting with different possible ways of stabilizing soufflés. Left: combining pastry cream with taro puree and taro powder.  Center: combining pastry cream and meringue elements.  Right: finished soufflé batters in ramekins.  The top ramekin contains a small amount of lemon juice, the center contains a higher meringue-to-pastry cream ratio, and the bottom one contains more pastry cream and less meringue
Many recipes online will claim to have a 'foolproof' soufflé, but few bother to explain why this or that formulation actually helps keep a soufflé stable. My initial thoughts were that the key to maintaining a soufflé's height after removal from the oven was to add more structural support, in the form of gelatin or methylcellulose.  These attempts were all met with failure.  Instead, I noticed that if I incorporated large amounts of meringue into my soufflé formulations, I saw more shrinkage of the soufflé as it cooled.  The behavior of the soufflé then is not unlike a cloud of gas, which can be defined by the ideal gas law,


Pressure * Volume = moles of gas * ideal gas constant * Temperature
(or PV = nRT)

Holding pressure, moles of gas, and the constant R constant, the volume of gases/air pockets within the soufflé are dependent on their temperature.  A drop in a soufflé internal temperature from 160 to 100 degrees Fahrenheit would result in a 10% shrinkage of air pockets (a somewhat larger drop in volume is observed since the soufflé air pockets are not gas impermeable - the moles of gas, n, within each pocket is not actually constant and may also drop with time).  While the cooling of the soufflé and shrinking of air pockets is unavoidable, the effects can be minimized by decreasing the meringue composition of the soufflé.  This was factored into the generalizable soufflé formula provided above.

Left: Soufflés immediately after 20 minutes at ~390 degrees Fahrenheit.  Center: Soufflés 5 mintues removed from oven.  Right: Soufflés 10 minutes removed from oven.  The leftmost ramekin contains lemon juice, the center contains more meringue-to-pastry cream, while the right most contains more pastry cream-to-meringue by volume.  The key comparison is between the rightmost ramekins, where the soufflé with more pastry cream had a smaller deflation
I hope this guide helped clear up some questions about how to go about making soufflés, and will encourage you to go out and try to make soufflés of new and interesting flavors! In the future I may post more articles on some more out-there flavors I made, as well as more advanced things you can do with soufflés.