In fact, you cannot really tell it until you make it – until you have made it several times.
How can you tell if a gnocchi recipe is good? Why gnocchi?
I have chosen gnocchi because there are hundreds of different recipes, it is a classic staple of Italian cuisine, and if the recipe is good, it is delicious. (According to Massimo Montanari, Professor of Medieval History at Bologna University and scholar in Food studies, gnocchi has been a favorite recipe since the Middle Ages.)
In this post and in subsequent posts, we will study the various recipes and procedures for making gnocchi that you can find online. We will see that some recipes are good because they include photos of key steps, some are good because they explain how to vary the recipe depending on qualities of the key ingredients, and some are good because they are bad, because they show you what not to do.
Gnocchi has only two main ingredients: potatoes and flour. Flour comes in varieties of course, but not too many, and if you use a good brand, then the product will be quite consistent from package to package. Potatoes are a different story. Not only do they come in different shapes and sizes, but as we will see in more detail below, they vary enormously in terms of other qualities such as the amount of starch.
My mother’s rule of thumb – which is a common one—is that “the weight of the flour should be half that of the cooked potatoes”. Some people say this is too much, some people recommend using only yellow potatoes, and others say the potatoes must come from last year’s harvest. My advice is to add a small amount of potato starch to get a fluffy texture.
There are a few other elements to consider, such as the temperature of the mashed potatoes and how long to knead the dough (it should never be over-kneaded). Here things become interesting, because the answers depend critically on the potatoes, in particular, on how much starch they contain. In his book On Food and Cooking, the famous food scientist Harold McGee says that there are two main varieties of potatoes: one is drier and more chalky, the other is moister and more dense. For reasons that are not entirely clear, the chalky variety contains more starch (p. 219). Unfortunately, it is difficult to tell which kind of potato you have just by looking.
As McGee explains, starch molecules generally love to attach themselves to water molecules and change their texture, but this phenomenon varies depending on the temperature of the water. Also, after being heated, as they cool the structure of starch molecules changes again and they release liquids. Thus, the overall texture of dough made with potatoes changes twice when cooking. This is critical to understanding why the temperature of the mashed potatoes influences the amount of flour the potato mash can absorb, and how the texture will turn out after cooking (and cooling). For example, when you add flour to hot potatoes, you get a dough with a soft texture. However, the gnocchi made from such a dough often turn out to be hard after cooking, with a strong taste of flour. The result will be different, if you add the same amount of flour to cold (cooked) potatoes. Generally, it is best to add the flour when the potatoes are warm – not too hold, but not yet cold.
This is my recipe.
Large potatoes 2 (about 550 gr. once cooked). Note: you must weigh the potatoes after cooking.
All-purpose flour, half the weight of cooked potatoes (about 226 gr.)
Egg yolk 1 (optional, see below)
Potato starch 1 tablespoon
Boil potatoes – skin on – in salted water until they are soft.
Drain potatoes in a colander, peel, and pass them through a potato masher pressing them directly into a bowl. Check the weight of potatoes. Since the flour should be half the weight of the boiled potatoes, you will then get the right amount of flour. Let stand until warm to the touch.
Add the potato starch, salt, the egg yolk, and add the potatoes. Quickly mix them but do not over-knead (about 2 minutes).
Place the dough on a chopping board you have previously dusted with flour. Using your hands, press the dough into an oval 1.5 cm, adding flour if needed.
Cut dough into long strips, 1.5 cm wide. You don’t need to roll them, and this way you avoid adding extra flour (you do not want to add too much flour since it can make a mess of the cooking water).
Cut into small pieces – about the same size as large olives.
Roll the gnocchi on a fork to make grooves. This gives them a nice shape and the grooves also help hold the sauce.
Meanwhile, bring the water to a boil and add the salt.
Add the gnocchi, gently mix them with a wooden spoon, and cook them for about 3 to 4 minutes. The gnocchi are cooked when they float at the top of the boiling water.
Strain the gnocchi, then mix them with about half of the sauce. Place on plates and top each serving with a large spoonful of the reserved sauce.
Sprinkle with grated Parmigiano cheese, serve and enjoy!
McGee, H. (2004). McGee on food and cooking: an encyclopedia of kitchen science, history and culture. London: Hodder & Stoughton.
Montanari, M. (2011). Il riposo della polpetta e altre storie intorno al cibo (Laterza). Roma: Laterza.
This recipe was prepared in Boston, Massachusetts, in the month of February 2019.