Rolling technology of long fried green tea
Rolling is a process of shaping the strip shape of roasted green tea after being killed. It plays an important role in improving the taste concentration of tea. At present, most of the green tea rolling has been mechanized, so today we mainly introduce the use of the kneading machine to roll the roasted green tea.
At present, there are four common types of green tea kneading machines: 40, 45, 55 and 60. Type 40 means that the diameter of the kneading barrel of the kneading machine is 40 cm, the same for other models. When rolling green tea, the model is too large or too small is not good, the most suitable and most commonly used is type 55.
There are two kinds of rolling techniques for green tea: cold rolling and hot rolling.
(1) Cold and soft
Cold rolling refers to the rolling of the green leaves after cooling. The rolling of young leaves generally adopts cold rolling. Because the tender leaves have less fiber, greater toughness, thin cuticle, and more water-soluble pectin content, it is easy to form strips when rolling, and the tender leaves can keep the bright yellow green soup color and the tender green leaf bottom after cold rolling.
(2) Hot kneading
Hot rolling refers to rolling the green leaves when it is hot instead of cooling. The old leaves are usually kneaded by hot rolling. Because the old leaf fiber is many, the leaf quality is thick and hard, it is not easy to form a strip when rolling. In the process of removing green leaves, the heat will soften the leaves, which will help to tighten the strips, reduce the broken tea and improve the appearance quality of the tea. Therefore, hot rolling is adopted.
The amount of leaves should also be controlled appropriately. Too few leaves will reduce the effect of rolling pressure and it is difficult to knead the strip; if too many leaves are thrown, the turning of the leaves in the kneading barrel is blocked, and the rolling is uneven, so it is easy to have debris and flat strips.
The leaf amount of the four commonly used models is: 10 kg for 40 type, 15 kg for 45 type, 35 kg for 55 type and 65 kg for 60 type.
There is a very important pressing process in the process of rolling, which has a great influence on the tightness and flattening of tea strips; the degree of rolling has a greater impact on the damage rate of tea tissue and the color and flavor of endoplasmic.
The principle of pressurization is from light to heavy, and then from heavy to light.
If the whole rolling time is 30 minutes, the pressurization procedure is generally as follows: 5 minutes for air pressure or loosening pressure, 12 minutes for pressure, 12 minutes for pressure, and the last minute for air pressure or loosening pressure.
How long a complete rolling process should last depends on three principles: one is to see the tender and old leaves; the second is to look at the diameter of the kneading barrel; the third is to see the tightness of the rope. The time of rolling the first and second grade fresh leaves is 20 ~ 25 minutes.
The rotation speed of the rolling machine is also very important, generally 48 ~ 50 revolutions per minute is the best. If it is too fast, it will produce more broken tea and affect the quality of tea.