What to do with leftover mashed potatoes?
Quick Answer
To best utilize leftover mashed potatoes, transform them into crispy potato cakes by combining with an egg, a tablespoon of flour, and pan-frying in olive oil at medium heat for 3-4 minutes per side until golden brown, or use them as a creamy topping for a shepherd's pie baked at 375°F (190°C) for 25-30 minutes. You can also create simple potato croquettes by rolling them into 1-inch logs, breading with panko, and deep-frying at 350°F (175°C) for 3-4 minutes until crisp and heated through.
Understanding Leftover Mashed Potatoes
Leftover mashed potatoes are a common occurrence after large meals, particularly holidays, offering a versatile base for numerous new dishes rather than simply reheating. The key characteristic of leftover mashed potatoes is their tendency to stiffen and dry out slightly as they cool, due to the starch granules retrograding, which actually makes them ideal for shaping and frying into different forms. They typically maintain their quality when stored properly in an airtight container in the refrigerator for up to 3-4 days, making them a convenient ingredient for quick weeknight meals or weekend projects.
While reheating plain mashed potatoes can sometimes result in a gluey or dry texture if not done carefully, transforming them into entirely new dishes leverages their existing texture and flavor. This approach minimizes food waste and allows for creative culinary exploration without starting from scratch. Common transformations include frying them into crispy cakes, baking them into casseroles, or shaping them into pasta-like dumplings.
Understanding the properties of cold mashed potatoes is crucial; their firmness allows for easier handling and shaping compared to fresh, warm mash. This makes them perfect for binding with other ingredients like eggs, cheese, or herbs, and then holding their form during cooking methods such as pan-frying, baking, or deep-frying. The goal is to reintroduce moisture and new flavors while achieving a delightful new texture that often surpasses simple reheated mash.
How to Transform Leftover Mashed Potatoes Specifically
First, consider making Crispy Mashed Potato Cakes. For about 2 cups of mashed potatoes, combine them with one large egg, 2 tablespoons of all-purpose flour, 1/4 cup of shredded cheddar cheese, 1 tablespoon of finely chopped chives, and season with 1/2 teaspoon of salt and 1/4 teaspoon of black pepper. Mix thoroughly until just combined, being careful not to overmix. Then, form the mixture into 1-inch thick patties, approximately 3 inches in diameter. Heat 2 tablespoons of olive oil or butter in a non-stick skillet over medium heat. Carefully place the potato cakes into the hot skillet, ensuring not to overcrowd it, and cook for 3-4 minutes per side until they are golden brown and crispy.
Alternatively, construct a quick Shepherd's Pie. Begin by preparing your desired meat and vegetable filling, such as 1 pound of seasoned ground beef or lamb with 1 cup of mixed peas and carrots, simmering in a savory gravy. Spread this filling evenly in a 9x13 inch baking dish. Next, gently warm your leftover mashed potatoes with a splash of milk or cream if they are too stiff, then spread them uniformly over the meat layer, using a spatula or the back of a spoon to create an even topping. You can create decorative ridges with a fork for extra crispiness. Bake the shepherd's pie in a preheated oven at 375°F (190°C) for 25-30 minutes, or until the filling is bubbly and the potato topping is lightly golden brown. Allow it to rest for 5 minutes before serving.
For a more elegant option, prepare Mashed Potato Croquettes. Take about 2 cups of mashed potatoes and mix in one egg yolk and 1/4 cup of grated Parmesan cheese for extra flavor and binding. Divide the mixture and roll each portion into a small log, about 2 inches long and 1 inch thick. Set up a breading station with three shallow dishes: one with 1/2 cup of all-purpose flour, one with 2 beaten eggs, and one with 1 cup of panko breadcrumbs. Dredge each potato log first in flour, shaking off excess, then dip into the egg, and finally roll in panko until fully coated. Heat 3-4 inches of vegetable oil in a deep pot or Dutch oven to 350°F (175°C). Carefully fry the croquettes in batches for 3-4 minutes, turning occasionally, until they are deep golden brown and heated through. Remove with a slotted spoon and drain on a wire rack lined with paper towels, seasoning immediately with a pinch of salt.
Common Mistakes to Avoid
One frequent error is overworking the mashed potato mixture when adding binders or other ingredients, especially if you are making gnocchi or croquettes. Many people stir vigorously, but this can activate the starches in the potatoes too much, leading to a gluey, tough, or rubbery texture in the final product. To avoid this issue, mix gently and only until the ingredients are just combined, using a light touch with a spatula or your hands.
Another common mistake is not properly seasoning the transformed mashed potato dishes. Leftover mashed potatoes might have been seasoned for their original meal, but when combined with new ingredients like flour, eggs, or cheese, the overall flavor can become diluted. Many people forget to taste and adjust the seasoning before cooking. To prevent bland results, always taste a small amount of the raw potato mixture (if it doesn't contain raw egg) or add a little extra salt, pepper, or herbs during the mixing stage, then taste again after cooking.
Improper storage of the original mashed potatoes can also lead to issues. Leaving mashed potatoes out at room temperature for more than two hours can promote bacterial growth, making them unsafe to eat. Some people mistakenly think they can leave them out overnight. To avoid food safety problems, always refrigerate leftover mashed potatoes in a shallow, airtight container within two hours of cooking, ensuring they cool quickly and remain safe for up to 3-4 days.
Finally, attempting to simply reheat very dry leftover mashed potatoes directly in a microwave without adding any moisture is a mistake that results in a hard, unappetizing texture. Many individuals just put the cold mash in and zap it. This causes the remaining moisture to evaporate rapidly. To prevent dry, stiff potatoes, always add a splash of milk, cream, chicken broth, or a knob of butter before microwaving or gently reheating them on the stovetop over low heat, stirring frequently until creamy again.
Expert Tips for Best Results
When transforming leftover mashed potatoes, always consider adding a small amount of extra moisture and fat to restore their creamy texture and prevent dryness. A tablespoon or two of warm milk, heavy cream, or melted butter, stirred in gently, will significantly improve the consistency for dishes like shepherd's pie topping or forming croquettes, ensuring they remain tender and flavorful rather than stiff.
To elevate the flavor profile of any leftover mashed potato dish, incorporate fresh herbs or a sharp, flavorful cheese. For example, finely chopped fresh parsley, chives, or dill can brighten potato cakes, while a tablespoon of grated Parmesan or crumbled feta cheese mixed into potato croquettes adds a savory depth that differentiates them from basic preparations. This simple addition introduces complex notes that make the dish feel entirely new.
For ultimate crispiness when pan-frying or deep-frying potato dishes, ensure the fat is adequately hot before adding the potatoes. For pan-frying potato cakes, medium-high heat is ideal; for deep-frying croquettes, maintain oil at 350°F (175°C). A hot surface instantly creates a crust, preventing the potatoes from absorbing too much oil and becoming greasy, resulting in a perfectly golden and crunchy exterior.
If you have a larger quantity of leftover mashed potatoes and want to save them for future meals, they freeze exceptionally well. Portion the potatoes into freezer-safe bags or containers, pressing out as much air as possible to prevent freezer burn, and label with the date. They can be stored in a freezer at 0°F (-18°C) for up to 2-3 months. Thaw them overnight in the refrigerator before using in any of the suggested recipes, which saves time on busy evenings.
Frequently Asked Questions
How long can I safely store leftover mashed potatoes in the refrigerator?
You can safely store leftover mashed potatoes in an airtight container in the refrigerator at 40°F (4°C) or below for 3 to 4 days. Beyond this timeframe, their quality and safety may begin to degrade, even if they appear fine.
Can I freeze leftover mashed potatoes, and what's the best way to thaw them?
Yes, you can freeze leftover mashed potatoes for up to 2-3 months. Portion them into freezer-safe bags or containers, removing excess air. The best way to thaw them is overnight in the refrigerator, then gently reheat on the stovetop with a splash of milk or cream, or in the microwave.
What if my leftover mashed potatoes are too dry to work with for a recipe?
If your leftover mashed potatoes are too dry, simply rehydrate them with a tablespoon or two of warm milk, heavy cream, chicken broth, or melted butter. Mix gently until they reach a more pliable consistency suitable for shaping or spreading, ensuring they are not too wet.
What are some vegetarian options for using leftover mashed potatoes?
For vegetarian options, you can make potato and cheese pierogi fillings, vegetable shepherd's pie with a lentil or mushroom base, crispy potato cakes with herbs and spices, or even mashed potato fritters loaded with finely diced vegetables like corn and bell peppers. Gnocchi is also an excellent vegetarian choice.
What's the best way to reheat plain leftover mashed potatoes without transforming them?
The best way to reheat plain leftover mashed potatoes is on the stovetop over low heat, adding 1-2 tablespoons of milk, cream, or broth per cup of potatoes and stirring frequently until heated through and creamy. Alternatively, microwave them in 30-second intervals, stirring after each, with added liquid until warm and smooth.