Jacket potatoes are another name for baked potatoes that have been baked and served with the skin on, resulting in a crispy outer skin, or "jacket," and a soft interior. They are among the simplest and most popular of all potato dishes and are common in cuisines all over the world that utilize the well known vegetable. Many subtle variations on their preparation exist, but the basic idea remains the same.
Certain varieties of potato are more suitable for use as jacket potatoes than others. Potatoes tend to fall into one of two categories of texture, waxy and mealy. Mealy potatoes are higher in starch and are better suited to baking. Waxy potatoes, such as red potatoes, small white potatoes, and fingerling potatoes, are not as well suited to baking and, therefore, not good candidates for jacket potatoes.
The Idaho russet potato is by far the most common variety of potato used for baking and makes an excellent jacket potato, although many other varieties are also suitable. Typically, larger varieties with thicker skins are used. Larger potatoes are better in general than smaller ones because it takes longer for the inside to cook, giving the skin a chance to get crispy, a key feature of a good jacket potato. While many restaurants cook their potatoes wrapped in foil, this rarely creates the characteristic crispy skin and is simply a baked potato, not a proper jacket potato.
In their most basic form, jacket potatoes are simply washed and baked in a medium hot oven until crispy on the outside and soft and floury on the inside. Some cooks like to rub the skins with a little oil to help them achieve the crispy texture of a perfect jacket potato. Other techniques used for jacket potatoes include pricking the potato a few times with a fork or toothpick and coating the potato in kosher or other coarse grained salt. This also helps promote a nice crispy outer skin by absorbing some of the moisture from the interior of the potato and drawing it to the surface where it can evaporate in the hot environment of the oven.
Butter is the traditional condiment served with jacket potatoes. They are also often served with any one of several other toppings, including sour cream, diced bacon, chives, and cheddar cheese, all of which are very popular in the United States. Many cooks and restaurants around the world have their own favorite topping for jacket potatoes, and the possibilities are nearly endless.