Why should a dish as familiar as macaroni and cheese be placed under the culinary microscope? Precisely because it is such a staple of our gastronomic repertoire. I wager that almost all of you have made macaroni and cheese at some point – no doubt the Kraft Dinner or the Annie’s variety that appeals to every student or parent when exams or children are threatening. The more adventurous among you have put make-up on it by sprinkling a handful of bread crumbs over top and baking it in the oven, or perhaps gone the extra mile to really dress it up with some protein-rich tuna or ham. For the DIY crowd, dehydrated cheese product is a disdainful ingredient fit only for commandos and 5 year-olds, so real, gorgeous cheddars, goudas, and jacks are the gold standard measures of a mac ‘n’ cheese. Yet, now matter how it is prepared, the heart and soul of macaroni and cheese is in the eating. Warm and fragrant, the soft and sticky cheese lingers on the palate and stretches out the minutes, providing a relaxing and satisfying break in a busy schedule. Ah – gooey surrender.
Nina could probably eat macaroni and cheese every evening. In fact, if we are to take Nina at her word, she eats macaroni and cheese every day at her daycare, although she also says going to bed is dangerous and that my singing makes her ears hurt. Obviously she isn’t to be trusted. Despite trying my hardest to make each new batch of macaroni stand out from its many brothers and sisters, lately I really feel I have hit the wall. How much more inspiration can I haul out of a very, very dry well? Naturally, I do what I always do and let the researcher take over, combing books and websites in order to benefit from the work of so many others that have come to face this great existential dilemma – the macaroni void. By trawling the internet I have identified a true dichotomy of approaches when it comes to the question of macaroni perfection. So I have chosen to look closely at the two factions – the modernists, who challenge our very ideas concerning the dish, and the traditionalists, who prefer to follow a more cautious approach based on decades of time-tested artistry. Can we deconstruct such a classic without offending some vengeful cooking spirit? How do we go about the almost heretical examination of such a hallowed recipe? Specifically, my research led me to directly compare two different recipes for macaroni and cheese that I will broadly classify as roux-based, or sodium citrate based. In the roux camp we have the very highly esteemed team from Cook’s Illustrated, and in the sodium citrate camp we have the chefs of Nathan Myhrvold’s Modernist Cuisine.
It’s all in the emulsion
Let us ask ourselves – why sodium citrate? Or why a roux, for that matter? Both of these approaches serve the same purpose, namely to provide a thick, creamy cheese sauce that retains its consistency while cooking and cooling, stabilising what would otherwise be a terribly woeful looking hot mess of fat and water. Using one or the other will serve to emulsify the mixture of the two liquids that would naturally prefer to remain separated, dispersing the two evenly in a sauce that remains homogeneous and flows freely. A beautiful, velvet river of smooth sauce is one of the most desirable attributes in a macaroni and cheese, and the recipes from the two groups achieve this with two different emulsifying agents: starch in the form of amylose and amylopectin formed during the development of the roux, or sodium citrate added as a powder.
In a roux, equal parts of butter and flour are heated in a saucepan, effectively dispersing the starch granules in a mixture of fat and milk solids from the butter. Aside from developing flavour through browning reactions such as the Maillard reaction, this important step ensures that the granules will not clump together as the liquid, in this case milk, is added. As the starch absorbs water the particles swell, forming gels that first begin to make the sauce thicker. Given time and higher temperature the amylose and amylopectin slowly leak from the granules, creating a network of filaments that not only give a more viscous sauce, but trap the casein protein in the cheese and prevent individual molecules from coming together. These proteins then order themselves around the droplets of fat and water, forcing them apart and maintaining the emulsion to give a smooth sauce. Sodium citrate performs a similar job by grabbing the calcium ions held by the casein and swapping them for sodium. When this happens the shape of the casein is altered so that it now is perfectly suited to enveloping the fat and water droplets. Voila – the necessary emulsion is formed.
The bottom line is that protein from the cheese is being used to encapsulate small spheres of fats and water that would naturally like to bead together (think of drops of rain coming together on a window), holding them apart and maintaining the emulsion that gives us a thick, consistent cheese sauce. Either starch or sodium citrate make this possible, by changing the way the protein self-organises. Now that we understand the science behind the cheese sauce, we can put our knowledge to good use!
In order to create The Definitive Macaroni and Cheese we assembled a team of four experienced tasters: Sara and I, Nina, and a guest taster recruited with promises of all-you-can-eat fat and carbs and a bad movie. I had already tried the two recipes linked to above (The Cook’s Illustrated and Modernist Cuisine) and had made several observations, listed below.
Initial thoughts – The Cook’s Illustrated, roux-based macaroni and cheese
The recipe calls for a whopping 5 cups of milk. That is 1.25 litres of milk for 454 g of cheese and 454 g of pasta. In comparison, the Modernist Cuisine version uses a scant 0.4 litres or so of milk for a similar weight of dry ingredients. That is quite a difference, and my initial crack at the roux-based version led me to believe that the sauce was far too dilute, lacking a real depth of flavour and giving a watery mouth feel that was not terribly satisfying.
In the version I made for the taste test I used the most exquisite cheddar and Monterey Jack cheeses that Fromagerie Hamel had on offer, and I cut the volume of milk back to 750 mL.
Initial thoughts – Modernist Cuisine sodium citrate based macaroni and cheese
Let me first say that this is an incredibly straight forward approach to making a cheese sauce. On my first attempt I simmered water and sodium citrate while adding the shredded the cheeses, mixing as noted with a hand blender. The final sauce was incredibly smooth, a truly homogeneous liquid that for all intents and purposes was molten cheese. I was astounded at the absolutely velvet texture, but I feared that it was actually too smooth. The mouthfeel was industrial, artificial, and there was an unpleasant saltiness and slight sourness from the sodium citrate. I was amazed, but not satisfied.
The same cheese blend was used. I missed the pleasant texture and odour that comes from milk, and I desired less of the sodium citrate flavour, so in the test version I cut back the sodium citrate in half and substituted milk for water, counting on the extra protein in the milk to make up for the drop in the amount of sodium citrate.
The taste test
The mac ‘n’ cheese recipes were served in two variants, with both the roux-based and sodium citrate based being additionally offered as baked and not baked. I also put two toppings on the table – chopped chives and finely cut bacon. I was interested to hear how the additional salt and smokiness of the bacon, or the bright, herbal aroma of the chives would balance the dish. Both, or none at all?
The results were much as I would have suspected. Despite using the hand blender to mix the finely grated cheese into the roux-based béchamel, this sauce was noticeably gritty and cereal tasting with much less cheese character, no doubt due to the fact that the volume of milk used was so large. The sauce also tended to separate easier, with small pools of water and tiny clumps of solids visible on sitting. The baked was preferred to the non-baked, with the crisp top and slightly more cooked pasta imparting a pleasing crunch and chewiness to the dish, and the crowd was divided over whether bacon or chives were best, or even necessary at all. Some wanted both, some wanted more bacon. The chives gave colour and a fresh flavour that was a counterpoint to the rich, baked pasta and cheese, and tasters also clamoured for freshly ground black pepper.
While there was some debate over the toppings, there was no debate over the superiority of the Modernist Cuisine version. The cheese flavour burst onto the palate, and the use of milk instead of water gave an improved texture and sensation in the mouth that made the sauce feel more natural. Decreasing the amount of sodium citrate also resulted in more farm and less factory feel, and as the macaroni and cheese cooled a lovely, sticky sauce formed that held its shape infinitely better than the roux-based one. This was the winner, with the baked version edging the non-baked by virtue of its enhanced texture and decreased sourness. It was crunchier, more flavourful, and more mature. A final note was an experiment in browning the top with a kitchen torch instead of baking in the oven. Though the top was tasty, the difference in the pasta and sauce texture with the baked version handed it the nod. Winner declared – the modernists leave the field of battle victorious.
The Definitive Macaroni and Cheese
280 mL milk
125 g aged cheddar cheese
125 g Monterey Jack cheese
6 g sodium citrate
250 g macaroni
freshly ground black pepper
handful of chopped chives
handful of chopped bacon (optional)
Prepare the pasta in boiling water with added salt. Cook until just past al dente, then drain the pasta and set aside.
Simmer the milk on low heat while stirring in the sodium citrate until dissolved. Grate the mixture of cheeses and add portion-wise to the milk and sodium citrate, processing with a hand blender. Continue until all of the cheese has been added, then continue to heat to 70ºC (155ºF). Mix with the pasta, portion into small bakeproof dishes or ramekins and place in the upper portion of the oven at 375ºF for 10-15 minutes until the top begins to brown. Remove and serve with toppings.
Feel free to experiment with cheese mixtures. For a rugged winter macaroni and cheese I recently used a blend of 200 g of admittedly cheap cheddar with 50 g of raclette cheese. Real lumberjack fare!