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.