In beer production, the degree of turbidity of the fermented liquid is theoretically proportional to the concentration of the beer: that is, the higher the turbidity, this is related to the internal soluble material in the beer. But in the end, there should be a turbidity standard for the finished wine with the same concentration. This paper analyzes the influence of several key control points such as raw materials, saccharification, yeast, fermentation and filtration on the turbidity of finished beer and the measures to solve it.
1. Poor quality of malt
The main reasons for this are mainly due to the low solubility, high viscosity, low brittleness, high β-glucan content, and the large number of soluble substances in the middle and macromolecules. These macromolecules are still suspended after filtration and even boiling. In the Wort, Causes an increase in the turbidity of the juice.
(1) Decomposition of quasi polymer substances in wort using compound enzyme preparations containing protease, glucosinase and amylase.
(2) Use of proteins, polyphenols, precipitators or clarifying agents. Such as tannin, carrageenan, etc. to remove the "turbid material" in the juice.
(3) Appropriate increase the proportion of auxiliary materials and "flush" polymer materials.
(4) Strengthen iodine screening during the glycosylation process so that the iodine screening reaction during the glycosylation process is complete.
(5) Malquality malt is generally not used alone. Add some good malt. In addition to preventing some undesirable phenomena, it may also be used interchangeably to achieve a multiplier effect.
2. Smash and use ratio of malt
The comminution process of raw materials is not controlled well, and too thick or too fine will affect the turbidity of the wort. Excessive raw material will not only affect the precipitation of leachate, but also lead to the filtration layer too loose, so that a large number of macromolecular components dissolved; If it is too thin, some substances in the epidermis of malt will be precipitated and it will be difficult to filter. In general, the lower the proportion of good malt use, the increasing turbidity of wheat juice; With the increase of the proportion of accessories, it can indeed reduce the proportion of large molecules in the Wort, but the proportion of accessories is too high, and the number of low-molecular dextrins that are difficult to decompose in wort will increase, which will also promote the turbidity of wort.
(1) Control the comminution of raw materials and determine the best comminution roll pitch.
(2) Reasonable matching of poor quality malt and auxiliary ingredients in raw materials.
3. Wheat juice filtration factor
Wheat juice filtration is a very important process in the beer production process. Its purpose is to separate the substances dissolved from the raw materials in the saccharification process from the insoluble wheat grains in the shortest possible time after the saccharification process. To obtain clear wheat juice, And obtained a good leaching rate. The filtration effect of wheat juice directly affects the late fermentation of wheat juice and the filtration of sake and the foam and flavor of beer, and ultimately affects the turbidity of beer. Therefore, controlling the turbidity of the "semi-finished product" is also very important for controlling the turbidity of the "finished product".
In the filtration process, the control of washing water temperature is very important. With the increase of washing water temperature, the turbidity of wort is decreasing. However, the water temperature is too high and the turbidity will rebound. This is due to the high temperature of the water, which causes the residual starch material in the liquid to paste again, which will also cause excessive washing. At the same time, maintain a steady filtration speed and suitable tillage depth to ensure the formation of filtration layer and smooth self-flow of Wort, improve the brightness of wort. However, if the operating process frequently opens the cultivator, or the cultivator is too deep, it will destroy the bad layer formed and cause the muddy juice.
(1) Control of suitable washing water temperature.
(2) Maintain a steady filtration flow rate and a suitable depth of the cultivator, and maintain the filtration layer.
4. Wheat juice boiling strength is not enough
The boiling strength of the wort in the boiling pot will directly determine the clarity of the Wort, because the wort has undergone intense physical and chemical reactions during the boiling process. In the meantime, the concentration process of wort is also a process of clarification of Wort, including the removal of hot coagulants and the elimination of undesirable volatile substances. Therefore, controlling the boiling strength plays an important role in ensuring the quality of wort and preventing the oxidation of wort.
Boiling intensity is too large, which will accelerate the colouring reaction of Wort, and at the same time will destroy the distinction of Wort, affecting the foam performance of beer. The longer the boiling time, the more solidified the number of proteins, but too long, some of the solidified proteins and their complexes will be redissolved and the wort will further deteriorate; If the boiling strength is not enough, or the pH of the wort is not properly controlled, the boiling steam pressure is not stable, etc., the coagulability nitrogen of the wort will not be enough, which will affect the turbidity of the wort.
(1) Determine the reasonable boiling time and intensity.
(2) To ensure, as far as possible, the stability of the supply of steam pressure during production.
(3) Add the used hops to keep them as fresh as possible during the boiling process, because the use of too old hops is oxidized, and the ability of the tannins to precipitate proteins will decrease, resulting in large molecular protein residues in the juice. More.