How about potatoes? Learn about the different types and methods of preparation
Mashed potatoes, fries , and a dozen other 'simple' dishes can easily go wrong if you don't follow the basic steps in their preparation and don't realise that the procedure and recipe depend on the characteristics of the different types of potato. The result of your efforts usually depends on three key factors: variety, cooking type and correct technique.
One ingredient, many varieties
When choosing potatoes, the cook should first find out what kind and what variety of potato is involved. While we can only distinguish between varieties early (harvested before 31 August), semi-early, semi-late and late potatoes (harvested after 1 September), the number of varieties in the Czech Republic is estimated at 170.
German and Dutch companies at the end of the 1990s, but also the accession to the EU, which led to the creation of a common catalogue with more than 1500 potato varieties, helped to ensure such a diverse range. Only registered potatoes can be grown in the Czech Republic, of which there are 158, but there are usually only around ten in the fields and markets.
Among the very early potato varieties, which can be harvested after 90 to 100 days, include Anuschka, Colette, Astoria and the red Rosara. Newer varieties such as Prada, Katy, Cidlina and Val blue, which contain three times the amount of antioxidants of those commonly available, can also be bought from farmers.
Early varieties are easy to peel and, unlike late varieties, have less starch and more water and protein. Popular varieties include Dali, Gala, Marabel, Adela, Anatori and Keřkovské rolls, which are very popular in the kitchen.
Mid-season potatoes are suitable for longer storage. The well-known varieties are Laura, Bernina, Antonia, Karin, Red Anna, Asterix and Stilleto.
Late varieties are often encountered in industrial cultivation. These include tubers called Marena, Mozart, Nicola, Samantana or Cecilia.
Cooking type and technique
Another question mark is the correct cooking type, which indicates the appropriate processing method. According to this criterion, potatoes are divided into three basic types: A, B and C, or AB, BA, BC or CB, in which the characteristics of each category are intertwined. Sometimes you will hear of only two groups: tallow (type A) and floury.
The letter A refers to potatoes with less starch and firm flesh, which is usually not cooked and does not soften. They are therefore used to prepare salads or side dishes such as peeled potatoes and gratins. Group B potatoes are those with a little more starch and a medium firm flesh. They have a versatile use as as a side dish, they can be boiled, baked, roasted or added to stews, soups, batters or mashes.
The last cooking type C makes potatoes suitable for mashing or to make potato batter, because of the very floury flesh, the rougher skin, the higher starch content and the tendency to crumble when cooked.
Notes from the kitchen
Everyone potato recipe calls for proper technique, and if we wanted to break down step by step even just the most famous potato dishes, we would have to expand this article into a book. Whether you boil, fry or mash potatoes, bake them in ash or confit them in goose fat, cook them sous vide with a little thyme and fat, or grate them into potato batter, you'll find the following tips from our chefs useful.
When cooking, watch the starch content of the potatoes, specifically amylose, which is found in starch grains. This is what is involved in the processes that play a key role in recipes.
Before boiling, frying and baking, scrape and cut the potatoes thoroughly rinsed thoroughly in cold water to wash out as much starch as possible. This is particularly useful for dishes in which the potatoes should remain crisp (e.g. chips and roast potatoes).
However, for some potato dishes, washing is omitted as the starch will help to improve the result. For example when making mash or puree, more starch is not a problem, but if you want to make mash with boiled type A potatoes, it will be difficult to boil them and process them to the right consistency.
Remember that mash should never be blended as a matter of principle, but whipped! Blending is too aggressive, it will disrupt the starch molecules in the potatoes and the amylose will produce a lot of gel which will make the mash a sticky glue. The ideal tool is a meat grinder, and a mortar and pestle for mixing.
The consistency of mashed potatoes can also be spoiled by mashing overcooked potatoes. Heston Blumenthal recommends them cook in two stages. First, they are gently boiled at 72ºC for 30 minutes to soften the texture of the potatoes, then cooled (which is called retrograding the starch) and cooked until tender.
Leave the potatoes in the hot pot before mashing them, to allow them to evaporate the steam and any excess liquid, which is not desired in the next steps.
Reheated mashed potatoes may turn gelatinous. Therefore, incorporate enough fat to coat the starch molecules and ensure a velvety consistency.
Joël Robuchon's famous mashed potatoes
- 1 kg potatoes of the same size, cooking type B
- 200-300 ml whole milk
- 250 g butter
- salt
- Wash the potatoes well, but do not peel them. Put them in a saucepan and cover with cold water so that it reaches 2 to 3 cm above them. Add 10 g of salt for every litre. Bring the potatoes to the boil and boil them for about 25 minutes until they slide down a knife you stick in them to test.
- Peel the potatoes while they are still warm and strain them. Do not use a blender or whisk and allow excess moisture to evaporate.
- Pour a few tablespoons of water into a saucepan, add the milk and bring it to the boil.
- Dice the cold butter into the mashed potatoes and stir with a spatula. Slowly add the hot milk, and when the consistency of the mash becomes smooth, take a whisk to stir it.
Tip: If you want the mash to be really silky, strain it through a colander at the end.
The key to success is technique: Boil the potatoes whole, mash them while still warm, let the excess liquid evaporate, add cold butter and hot milk.
If you want the perfect fries, buy the starchiest potatoes possible. These are rinsed first, then then boiled in unsalted water and fried twice - the first time at 130 °C, the second time at 180 °C. Between each stage, the potatoes are cooled in a freezer or a shocker to evaporate excess moisture. This keeps the fries soft and crispy inside.
Low starch potatoes can be sliced into dishes where they will keep their shape, such as salads or gratins. Always place them on the stove in a pot of cold water - gradually heating them to boiling point will ensure a good texture, which hardens at around 60ºC.
Do not cook potatoes in an acidic environment, otherwise they will not cook. This can be caused primarily by polysaccharides, specifically pectins contained in the cell walls. These form chains that are more stable due to contact with acid, so the pectins break down much more slowly and the potatoes remain hard. This is why, for example, the potatoes for cabbage soup are cooked separately.
Salt disrupts the pectin chains. Be sure to salt the water when cooking the mash, but pre-cook the potatoes for chips and roasting in unsalted water so that they remain firm enough not to boil.
Before frying or baking, always boil and cool. Their surface cracks a little, and when the fat gets into the cracks, they are pleasantly crispy.
If you want baked potatoes to take on a golden brown colour, let them cool first. Some recommend chilling them briefly, others leave them in the fridge for a day or two. Chilling converts some of the potato starch to sugar and promotes browning. The potatoes only need to be refrigerated for an hour or two before frying, as this process transfers heat more quickly and could easily burn the potatoes.
You can also use the potatoes as a delicious thickener sauces or soups. They work as emulsifier, which means they can combine two heterogeneous liquids. That is why the mashed boiled potato is added to emulsions that are split. Examples are brown butter egg emulsion, mayonnaise or mixtures to put in espuma.
Much of the flavour and a lot of the umami is found in the skins, because they're the ones that are in contact with the microbes in the soil. In recipes that allow this, process the potatoes with the skins on or use the skins to flavour potato dishes. For example, cream infused with baked potato skins does a great job in mashed or pureed potatoes, and the dust from the skins can be an interesting detail on the plate.
Cooked potatoes are usually not so sweet because their natural sugars are released into the water. Once you add 1 g of sugar per 100 ml of water, you create the same concentration as in the potato, and the natural sugars are retained inside the crop.
In addition to the choice and method of treatment, storage of the potatoes is also important. They need a dark, well-ventilated area, dry and cool. Heat is just as damaging as frost - while higher temperatures cause premature germination, reduced nutritional value and increased formation of toxic solanine in the tubers, frost converts starch and damages the tubers. The potatoes then become weaker and spoil more quickly. The ideal storage temperature is between 4 and 6 °C.
Apples are also an enemy of potatoes, so do not store them together. The ethylene released from the apples speeds up the metabolism of the potatoes and they start to sprout too early. Apples, on the other hand, readily absorb potato flavour.
Excellent partners to potatoes in the kitchen are bacon, cheese, onions, chives and sour cream, cream, garlic, parmesan, rosemary, leeks, nutmeg and fish.
Do not rely on the general characteristics of the varieties. Potato characteristics are also influenced by region, soil and growing method and so the same variety may perform differently. It is important to have a supplier, ideally the farmer himself, and to test the potatoes in the kitchen before ordering a metre of them.
Did you know that:
The potato is native to South America. The Incas started growing them in Peru, Bolivia and Chile, and Christopher Columbus brought them to Europe in the 16th century. To the Inca people, the potato was a godsend, and there is even evidence of the worship of potato deities. They preserved the precious raw material as dried powder (chuño), made an alcoholic drink from it resembling beer and reportedly used it in medicine.
Potatoes are said to have first appeared in Czech cuisine around 1623, specifically on the plate of the Supreme Chancellor of the Bohemian Kingdom. However, it did not become popular until the 18th century, when it began to be cultivated in Brandenburg (hence the etymological origin of the Czech word 'potato') and spread to Bohemia. Wars, poor harvests and famines also played a role.
Potatoes won a privileged position in Czech cuisine and our diet in the first half of the 19th century. Today their consumption is around 70 kilograms per person per year (69.1 kg in 2017).
Despite the high consumption, we as the Czech Republic are only one-quarter self-sufficient. Most of our potatoes are imported from Germany.
Potatoes also have popular regional names. In various regions you will still hear names such as 'zemské jabko' ("earth apple") and 'jabka', erteple, kobzole, grumbíry, okroše, krumpla, zemky or zemčata.
The potato contains solanine, a bitter substance that makes it poisonous. Solanine is, however, much less concentrated in the tubers than in other parts of the plant and loses its toxic effects through cooking, so that potato poisoning is rare. Solanine is found in the greenish and sprouted skins of potatoes that have been stored for a long time at high temperatures and in the light.
Potatoes are not really the saviour of over-salted food. We thought so too, but if you salt two pots of water, boil a potato in one of them and then compare the salinity with a refractometer, you will find that the salt concentration is the same in both liquids. The best way to reduce the unwanted salty taste is to dilute the dish with water, cream, milk or other non-salty liquid.
Source: Ambiente Chefs, Fine Dining Lovers, Great British Chefs, Heston Blumenthal, CSO, Potato Catalogue, Potato Research Institute
