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Wort Lautering Process In Beer Brewing (Part 2)

Mar. 09, 2020

This time, we continue to reveal the remaining three processes of wort filtration.


5. First wort filtration

The filtration time of the first wort is generally about 60 min. If an advanced new filtering system is used, coupled with good digging operation, the filtering time can be reduced to 60 minutes.

When the reflux wort is clear, the reflux is over. Open the valve that enters the boiling pot or wort storage tank to allow the wort to enter. In order to maintain the looseness of the malted layer, the filtering pressure difference should be kept as small as possible. When the filter valve is opened, it should not be too fast. At the beginning, it should be controlled at 1 / 4-1 / 3 opening, and then gradually open the large valve according to the wort brightness and filtering time requirements.

During the filtering period, a cultivator can be started to plow the soil to loosen the filter layer and improve the filtering speed. However, the speed of the tiller should not be too fast, and 1 / 5-1 / 3r / min is appropriate. The height of the cultivator should be from top to bottom, but the minimum distance of the final filter plate is about 3cm. It must not be too low to avoid damage to the filter plate by the cultivator.

When filtering for 15-20min (or according to specific conditions), determine the first wort concentration. In order to ensure the final wort concentration, the first wort concentration must be about 40% higher than the shaped wort concentration. If beer is produced at 12 ° P, the first wort concentration must be around 16 ° P.


Factors affecting first wort filtration

* Wort viscosity

The higher the temperature, the lower the wort viscosity and the faster the filtration speed.

* Malt resistance

At the beginning of filtration, the resistance is the smallest. As the filtration process progresses, the resistance becomes larger and larger.

* Filter operation

The filtration operation is not static and must be adjusted as the resistance of the wheat trough changes. And there are many factors that affect the wort filtration, such as malt quality, saccharification method, pulverization composition, filter sieve plate load and filter plate structure, initial filtration operation, etc., the filtration operation should be adjusted flexibly according to some practical factors.

* Malt quality

With good quality malt, there are relatively few upper and lower particles in the filter layer. Studies have shown that, under the same pressure, in the first wort filtration stage, the lower particles and the malted layer play a leading role; during the washing stage, the upper particles play a dominant role. It can be seen that in order to accelerate the filtration speed of the first wort, it is necessary to reduce the formation of particles in the lower layer.

With good quality malt, the wort obtained has low viscosity, relatively low malted grains, fast filtering speed and short filtering time. Generally, the wort viscosity is low, so the filtration time is short. However, there are exceptions, such as strong stirring during saccharification, and the barley in mashed mash is broken. Even if the wort viscosity is low, the filtration time is still long.

* Amount of excipients

Particles such as protein, hemicellulose, starch granules, and lipids that are not broken down during saccharification affect the filtration speed of the wort. The amount is related to the degree of malt dissolution and the type and amount of added cereals. Sometimes saccharification and addition of β-glucanase is a favorable measure for filtration, which can improve filtration.

* Crushing method

The filtration speed of wet pulverization is significantly higher than that of dry pulverization and humidified pulverization.

The thickness of dry pulverized lees layer is about 35cm, humidified pulverized is about 40cm, and wet pulverized is about 55cm. It can be seen that when the husk remains intact in the crushed material and the husk volume is large, the malt layer formed is relatively thick, and the feeding amount per unit sieve plate area can be increased from 200g / m2 to 225kg / m2 Even 300kg / m2.


Inspection of the first wort

The quality of the first wort is very important, it is a mark to test the quality of malt and the result of saccharification operation. The wort color, brightness, odor, taste, and iodine response are easy to check.

The color of the first wort is checked with each filtration, and the color of the mixed wort, shaped hot wort and cold wort, and finished beer can be predicted.

It is more important to check the clearness of the wort at different filtration stages. Generally, after 10 minutes of filtration, the brightness of clearing should reach a satisfactory level. Although the wort layer is tight, although the brightness of filtered wort is improved, it is obviously difficult to filter. However, when plowing the grain, it has a certain effect on the brightness of wort.

The quantity and concentration of the first wort should be measured in time, so as to calculate the yield of the first wort and the amount of washing waste water added. Generally, when a wort is produced using a small atmospheric pressure filter tank, the first wort yield is generally about 50%.


Method for measuring wort concentration

The wort concentration was measured by a sugar meter. The temperature-dependent sugar meter is a float meter, which is made according to the principle of liquid densitometer. The smaller the relative density of the liquid, the deeper the densitometer sinks. The bar of the sugar meter is engraved with a mass percentage scale. Because the sugar meter is calibrated with a sucrose solution, the sugar meter is also called a sucrose sugar meter.

The measurement needs to be performed at about 20 ° C. Take a certain amount of wort and place it in a metal tube, and cool the wort to about 20 ° C. Make sure the wort is not diluted when cooling. When reading, be sure to look up and take the reading from the convex scale where the wort is in contact with the fine bar of the sugar meter. See the reading of the sugar meter to practice, because the liquid level of the fine meter of the sugar meter in the metal cylinder will rise slightly, so you cannot take a reading at the plane, you should read the scale value at the clearest line of the convex surface. But in the laboratory, the reading of the sugar meter is from the lower end of the meniscus, because the laboratory measures the sugar meter in a glass cylinder. Therefore, when measuring wort concentration, we must pay attention to whether the sugar meter reads from the upper or lower end.

In order to obtain the most accurate measurement results, the wort concentration must not be changed. Before the sugar meter is immersed in the wort, it must not be washed with water or other liquids, but should be washed with the same wort measured in the measuring cylinder. In order to make the wort temperature in the measuring tube mix evenly, a clean, dry mixing stick (also rinse the wort with the wort to be tested) and stir well.

The Brix meter is calibrated at 20 ° C. When the temperature deviates from 20 ° C, the correction value of the sugar meter is used. The correction value depends on the temperature of the wort measured. If the temperature of the wort measured is higher than 20 ° C, it means that the wort density at this temperature is lower than the density at 20 ° C. The correction value is added to the value displayed by the sugar meter. ; Below 20 ° C, the display value of the sugar meter must be subtracted from the correction value.

The temperature scale is always in the lower half of the sugar meter. As long as the lower end of the sugar meter is inserted into the wort, the calibration value can be displayed, and the red calibration data is on the other side of the temperature scale. The data listed on the scale in Figure 2 are the correction values at the corresponding temperature. If the reading of a sugar meter is 11.6 ° P and the correction value below 20 ° C is 0.2 ° P, the wort concentration is 11.4 ° P, that is, at 20 ° C, 100kg of wort contains 11.4kg of extract.


6.Sink

At the end of the first wort filtration, there is still retained extract in the malt. In order to improve economic benefits, it should be washed out thoroughly. This process is called washing up. The water used for washing the grains is called washing water, and the wort washed out is called the second wort. The leachate-containing water that flows out at the end of washing is called washing residue.


Washing up method

Generally, the washing of the lees is performed in two or three times. The amount of water used for washing the first time is about 30%, and the first wort is drained from the malted rice; the water used for the second washing is about 50%, so that the content of the extracts drops smoothly; the water used for the third washing is about 20%, and Wash out the extract from the malt.


Washing water

Although the higher the temperature of the lees, the faster and more thoroughly the lees are washed. However, it is also required. The water temperature must be controlled within the saccharification temperature range, generally 76 ° C to 78 ° C, and the maximum should not exceed 80 ° C. If the temperature is too low, the residual sugar is not easy to wash and easy to be infected. It will affect the wort filtration, enhance the wort oxidation, deepen the wort color, and affect the taste and flavor of beer in the future.

The amount of washing waste water depends on the amount and concentration of the first wort, the concentration of the wort in the full pot, and the evaporation of the boiling pot. The washing waste water has a greater impact on the wort yield. For the production of light-colored beer, saccharification is generally thin, and the amount of water used for washing the tank is small; for the production of thick-colored beer, saccharification of thick saccharine is generally used.


7. Discard bad

When the wort concentration reaches the process value, stop washing. Open the drain valve, dry the residual liquid in the malt, then open the windshield, open the malt drain outlet, start the cultivator and drop the waste scraper to drain the waste. After the drainage is finished, clean the cultivator and sieve plate and reserve.

The drainage should be carried out slowly from top to bottom, so as to prevent the pipeline from being blocked too quickly; do not plow the cultivation too deep to avoid the deformation of the cultivator; do not raise and lower the cultivator to exceed the upper and lower limit signs to prevent the cultivator from scratching the screen .

The lees discharged after the filtration has a water content of 70% to 80%. For every 100kg of feed, 100 ~ 130kg of wet wheat gluten can be obtained.

Malt contains a small amount of sugar and a large amount of protein, which is rich in nutrition and easily rancid. Therefore, effective treatment must be carried out immediately.


The secret to the wort filtration process has come to an end here. If you have any question, welcome to leave us a message!


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