Instant pots and pressure cookers take longer to come to pressure with frozen meat compared to non-frozen meat due to a few key reasons:
Heat transfer: When you place frozen meat in the pressure cooker, the heat needs to first penetrate and thaw the frozen surface of the meat before it can start cooking it. The frozen meat acts as an insulator, slowing down the transfer of heat to the interior of the meat. This process takes time and can significantly delay the cooker's ability to reach the desired pressure.
Increased mass and density: Frozen meat is denser and has more mass than its thawed counterpart. As a result, it requires more energy to raise its temperature and bring it to pressure. The pressure cooker needs to expend more heat and time to achieve this.
Initial water content: Frozen meat tends to retain more moisture, and as it thaws, this moisture starts to evaporate. This extra moisture can delay the pressure-building process, as the pressure cooker needs to generate enough steam to increase the internal pressure. This is especially relevant if you're using the natural release method after cooking, as the excess moisture may need additional time to escape.
Preheating time: Some pressure cookers have built-in safety mechanisms that prevent them from reaching full pressure until they detect sufficient heat buildup within the pot. When you start with frozen meat, it takes longer to generate enough heat inside the cooker to trigger the pressure-building process.
To expedite the pressure-building process when using frozen meat, some tips include:
- Cutting the meat into smaller pieces to reduce its mass and promote faster heat transfer.
- Using a hot liquid, like hot water or broth, instead of cold liquid in the recipe to help speed up the initial heating process.
- Partially thawing the meat before pressure cooking to reduce the initial heat transfer time.
- Adding a few extra minutes to the cooking time to account for the longer pressure-building duration.
Always ensure that you follow the manufacturer's guidelines for your specific pressure cooker model and refer to safe pressure cooking practices when cooking frozen meats or any other ingredients.