We can use “basket presses” or so-called “ratchet presses,” and on the other side, we have a more modern variant called “bladder presses.” These are the two most recognizable variants of the grape press machine. And what is the primary purpose of a wine press? The primary purpose is to separate the juice or fermented wine from the pulp, skins, and seeds. All those ingredients are the solid parts of the grape. This separation is done by squeezing which is a better procedure than let’s say a centrifuge. As customers, you have an opportunity to choose between a basket presses which are cheaper, but I highly recommend a bladder presses. Of course, you have to select the size of any presses depending on your quantity of grapes.
Purpose of Grape Pressing
In the process of the production of white wines, the pressing of the grapes is immediately followed, and at the latest the next day, if the white mash is cold macerated. A red must go to press after the maceration is completed, which, depending on the style and category of wine, can last from three days up to a month or more.
During the pressing, the hard parts are separated from the liquid (must). Increasing pressure increase the unwanted substance in the liquid. These problematic substances are presumably found in stems, seeds, and strawberries. Injuries do not only increase the amount of hard matter, but also the proportion of unwanted substances. The quality of the wine is therefore reduced. The extent to which grapes are damaged is also dependent on the elasticity and resistance of the strawberries.
Older Type of Grape Press Machine – Basket Presses
This type of grape press machine is based on various technical solutions. Pneumatic, horizontal high performance, and vertical, smaller capacity. Pneumatics are the most sought after, due to their large capacity, but also easy cleaning, which is very important in the short harvest season. Sometimes the white mash is pressed separately from red, and efficient cleaning is also a great advantage from this point of view.
The most traditional press, which was until recently extended in all cellars and is still in use, is the basket press. At first, the drive was manual, later it was upgraded with hydraulics and later powered by an electric drive.
Newest Type of Grape Press Machine – Bladder Presses
The development of presses has been very intense in the last 30 years. A specified period was the most widespread piston but was successfully excreted by the pressurized presses. A pressure in the drum is at most up to two bar, most of the must be drained at a pressure of up to 0.2 bar.
Equipment for Presses and Operation
The grape press machine is filled through the door on the drum or centrally. During the central filling, the mash is simultaneously draining. It is also possible for the drum to rotate during the central filling, which allows for the filling of a larger quantity of mash. However, simultaneous central filling of the mash and rotation of the drum increases the sediment and thus has a negative impact on the quality of the wine.
This is not such a dangerous process if the grapes are healthy. However, if the grapes are rotten or to mature, there is further damage to the tissue of the strawberry cells, which increases the proportion of colloids that make it difficult to drain the must from the drum.
The filling of the press should be carefully planned to take into account the specificity of the variety, year, a degree of maturity, a degree of rot. Preliminary procedures in the processing of grapes such as removing the stalk, pumping, and maceration time affect the compression result to a greater extent than the compression program itself, which includes pressure, cycle, and crushing of the cake.
Bladder Press or Basket Press.
How the Baskets Presses Operate?
Grape Press Machin os operating by pushing grapes or must from the top to the bottom. In the wooden basket, you give the must or the grapes until it is quite full. On the top, you place two pieces of wood in the form of a moon. At the top of this, then the wooden blocks are folded. Put the blocks by crossing them. Put them so much that they reach the height of the basket. Fold them next to the central-iron shaft. Then put the handle into the ratchet assembly. The handle is tightened with movement to the left and to the right, pushing the wooden blocks down.
In this way we get one of two results from those type of gape press machine:
1) In order to get as much juice as possible, we squeeze grapes, seeds, and stems too hard. The result is too much bitterness in the wine.
2) To avoid these unwanted flavors, do not squeeze too much. As a result, we get quite a good wine or juice but less.
How the Bladder Presses Operate?
These presses work by pushing grapes or must from the center outwards. So from the inside to the outside. This causes uniform pressure on grapes or must. In this method, there is no need to choose between quality and quantity. Also, it speeds up the work in this way. For this reason, we are satisfied with a smaller press. This makes the press easier to move because it is lighter and is usually on wheels. It is lighter for two reasons. In short, working with such a press is much more enjoyable. It’s also much easier to clean it.
Size od Grape Press Machine
The size of the press depends on at least three factors. How much grape I have to press? How much can I do in one cycle? How long will it take for each a pressing?
As with other procedures in wine production, the preparation time and the time we will use for cleaning are also crucial in pressing.
In any case, you do not want that the grape pressing lasts 12 hours or more. The goal should be a maximum of 5 hours of work.