Carnitas is a popular Mexican pork dish made by braising or roasting pork in oil or lard until crispy and tender. It is often served with tortillas, beans, salsa, guacamole, and other toppings as tacos, burritos, nachos, or by itself. While traditional carnitas recipes call for just pork, oil or lard, and seasonings, many modern recipes also incorporate milk.
The Purpose of Adding Milk
Milk serves several purposes when added to carnitas:
- Tenderizes the meat – Milk is a tenderizing agent. The proteins in milk help break down the pork’s muscle fibers through a process called denaturing, making the meat softer and more tender.
- Adds moisture – Milk adds moisture to the pork as it cooks, keeping it juicy and preventing it from drying out. The lactose and casein in milk are hygroscopic, meaning they attract and retain water.
- Promotes browning – Milk proteins brown and caramelize more readily than pork alone does. The milk solids coat the meat and speed up the Maillard reaction, enhancing browning and adding flavor.
- Makes crispy bits – When milk solids brown, they form crispy, browned bits of pork that provide texture. This gives carnitas its characteristic crispy edges.
- Neutralizes odors – Milk has a neutralizing effect that removes strong “porky” odors from the meat.
- Adds richness – Milk adds a creamy richness that balances out the other bold, spicy flavors in carnitas.
By making the pork more moist, tender, and browned, milk helps achieve the ideal texture and flavor of carnitas.
How Milk Reacts During Cooking
When milk is added to pork and cooked, several chemical reactions occur:
- Denaturing – Heat causes the proteins in milk (such as casein) to unfold from their natural state. The altered proteins then bind to proteins in the pork, disrupting their structure and essentially “tenderizing” the meat.
- Coagulation – Temperatures above 185°F cause the milk proteins to coagulate and clump together. This forms a protective coating on the meat.
- Maillard reaction – Sugars and proteins in the milk undergo the Maillard reaction, causing browning and the production of hundreds of flavor compounds.
- Caramelization – Lactose sugars caramelize, forming a sweet, nutty flavor.
- Evaporation – Water evaporates from the milk over time, concentrating its flavors and sugars.
Understanding these chemical changes helps explain why milk-braised pork turns out more tender and tastier than pork braised alone.
Types of Milk Used
The most common types of milk used to make carnitas are:
- Whole milk – The increased fat content makes the pork extra moist and tender. The fat also promotes more Maillard browning.
- Evaporated milk – Already partially concentrated, this lends intense flavor. It doesn’t dilute the braising liquid.
- Sweetened condensed milk – The added sugar accelerates browning through the Maillard reaction. It also gives the pork a sweetness that balances the other spices.
- Buttermilk – Provides tanginess, and the lactic acid tenderizes the meat.
- Coconut milk – For a dairy-free option, coconut milk substitutes well for regular milk. It gives a subtle coconut flavor.
The fat content and level of sweetness vary among these options, so the milk choice can be tailored to the flavor profile you want.
Recipe and Cooking Considerations
Here are some tips for successfully cooking carnitas with milk:
- Use a ratio of about 1 cup milk per 3-4 lbs pork.
- Marinate the raw pork in milk overnight in the fridge for increased tenderizing.
- Cook low and slow, at 300°F or less, to give time for the milk to permeate the meat.
- Don’t let the milk boil or scorch, as this will cause it to curdle and separate.
- Turn the pork every 30 minutes for even cooking and absorption of milk.
- Rest the cooked pork in the milk sauce for 10 minutes before serving for optimal flavor.
- Skim off some excess fat after cooking but leave a little for moisture and flavor.
The milk and cooking technique alter the nutritional profile of carnitas compared to plain roasted pork. The Maillard reaction creates advanced glycation end products associated with disease. Deep frying in lard also increases calories and saturated fat compared to oven roasting. Overall, carnitas should be enjoyed in moderation as part of a balanced diet.
Conclusion
Adding milk to carnitas imparts tenderness, moisture, browning, and richness to the pork. Milk proteins, sugars, and fats react with the meat during low, slow cooking to produce tender texture and robust, complex flavor. Choosing an appropriate milk type and following recipe ratios and cooking steps helps maximize the benefits milk provides in carnitas. While not the healthiest dish, the rich, irresistible flavors of milk-braised carnitas make it a beloved Mexican comfort food.