First, find the features.
If you want to buy real iron stick yam, you must first choose the characteristics of iron stick yam. To put it bluntly, there are dark purple patches on the surface of yam, like rusty iron bars, so it is called iron bar yam. Therefore, the first feature that the real iron stick yam needs is that there are obvious deep purple spots on the surface. Without this rust spot, it will never be a veritable iron stick yam, which is also a characteristic that needs to be possessed.
Second, distinguish the appearance.
Because of the different soil layers in which the iron stick yam grows, the iron stick yam can be divided into two kinds in appearance design: Lou Tu iron stick yam and Sha Tie stick yam, both of which have their own characteristics. However, both Loutu Tiegun Yam and Shatiegun Yam have the same characteristics on the surface except for the iconic rust spots: there are many slender hairy fibrous roots on the surface with a pore size of 2-2.5 cm. Beyond this size, most of them are not authentic iron yam. Among them, the iron stick yam with loam and sand has its unique characteristics:
Lowland iron bar yam: Lowland is a sticky red soil. Because of its high viscosity, solid soil layer and high hardness, most of the iron-stick yams planted and developed are flat, with more fibrous roots on the surface with low viscosity, and the aperture is similar to the size of a "1 yuan" coin, and the overall tone is dark gray.
Shatiebang Yam: Due to the soft sand layer, low viscosity and soft strength, the growing and developing iron bar yam has a pore size of 2-2.5cm, which is slightly thicker than loam iron bar yam and should be about the size of a "1 yuan" coin. Dioscorea opposita is round, smooth in appearance and has many slender hairy fibrous roots. Except for the representative "rust spots", the overall color is light blue.
Third, weigh the net weight.
Because of the pore size of iron stick yam, the weight of the whole yam is unlikely to be too heavy. Ordinary iron stick yam can't exceed 500 grams, which is similar to 200-250 grams. Take out an iron bar yam and weigh its net weight. Generally, it cannot exceed 250g. However, the unique and rich sandy soil is not excluded. The iron bar yam grows to more than 80cm, which is as heavy as ordinary iron bar yam. However, the net weight must not exceed 500 grams.
Fourth, judge the ductility.
The food we usually eat, yam or non-authentic iron bar yam, is generally extremely plastic and may be broken with a touch. Iron stick yam contains a lot of cassava starch, so its ductility is weak and has certain ductility. When it is gently Bai Wan, it generally won't be brittle and can't be broken at once.
Fifth, look at the cross section.
Because of the low starch content, the cross-section of non-authentic iron stick yam or edible yam is generally light in color, transparent and has more fresh cross-section exudates. Authentic iron stick yam contains more cassava starch, and its cross-sectional color is milky white with less exudation.
Sixth, taste the taste.
Authentic iron stick yam is delicious even if it is eaten directly after steaming. It has the characteristics of fragrant taste, thick flour, sweet taste and soft and waxy taste, and is generally called fragrant, flour, sweet and waxy. However, after the fake iron stick yam is steamed and tasted, it is very different immediately, showing its original shape, and most of them do not have the unique flavor, noodles, sweetness and glutinous taste characteristics of iron stick yam.
How to tell the true and false of iron stick yam? Master these six points, yam sweet noodle sauce is sweet and glutinous, and one is accurate. If you want to choose authentic iron stick yam, you must have these characteristics: 1, the iconic rash; 2. The aperture is similar to the size of "1 yuan" coin; 3. There are many fibrous roots on the surface; 4. Loam iron bar yam is oblate, dark in color and crimson, with sticky loam on the surface; Shatie yam is cylindrical, light in color, white and bright, and clean in surface; 5. The net weight of each iron yam is generally 200-250g; 6. It has certain ductility, weak ductility and is not easy to break; 7. The cross-sectional color is gray, with less exudation; 8. It has the characteristics of aroma, noodles, sweetness and glutinous of iron stick yam.