Wort Filtration Process(1)

The wort filtration process mainly includes seven processes: auxiliary hot water, mash feeding, standing, wort reflux, first wort filtration, washing and disposal spent grains.

〖Hot water〗

Before the mash is pumped into the filter tank, it must be checked whether the filter tank is in a normal state. First of all, clean the filter screen, lay it properly, and press it tightly, then check whether the tiller is in the normal position, check whether the pipeline valve connected to the filter tank is in normal state, and at the same time put the air baffle and pot door of the filter tank. Close it to ensure that the temperature of the entering mash does not lose temperature as much as possible; after the inspection, put hot water at about 78°C until there is no filter plate. First, discharge the air between the filter plate and the bottom of the tank to prevent wheat The oxidation of the juice, the second is to prevent the occurrence of air chambers to affect the filtration, the third is to preheat the sieve plate and the filter tank, and at the same time support the fine particles in the mash to ensure the normal filtration of the wort.

〖Mashing feeding〗

The saccharified mash needs to be quickly pumped into the filter tank while stirring; when the pumping mash is nearing the end, open a few laps of the tiller to make the distiller's grains evenly distributed to form a better filter layer and improve the wort filtration quality.

Since it is easy to absorb oxygen in the process of pouring mash, it is better to enter the mash from the bottom of the filter tank in principle.

〖Standing〗

After the mash is pumped into the filter tank, it needs to stand for about 20 minutes, and the wheat husks will quickly settle to form a 25~40cm thick layer of wheat grains, which mainly forms three filter layers: the bottom layer (composed of coarse grains and heavy grains), the main layer ( It is composed of wheat grains, which is the thickest layer and is also the natural medium for wort filtration) and the upper layer (composed of light particles such as protein and fine wheat husk debris precipitated in the mash, this layer is thinner), and the grains layer The clear first wort gathers in the upper part; resting is an essential process.

The sedimentation speed of the grains in the wort is related to the concentration of the wort, and it settles faster in the thin mash than in the thick mash. At the same time, it is also affected by the temperature. If the wort is well insulated, the wort layer will be looser, and the wort will be easier to filter. Therefore, attention should be paid to heat preservation during wort filtration to prevent the mash from cooling down. In addition, the better the saccharification process breaks down, the better the settling and separation of the filter layer.

〖Wort reflux〗

The clear and transparent wort contains a small amount of fatty acids, and the fatty acid content in the cloudy wort will be more than 10 times that of the clear wort; Problems such as rising, rising iodine value, poor protein flocculation and unreasonable composition of wort will not only bring adverse effects on the foam and flavor of beer, but also easily cause abnormal fermentation phenomenon. Therefore, at the beginning of filtration, the turbid wort must be refluxed to improve the clarity of the wort and prevent the occurrence of the above problems.

After standing, many fine particles are gathered between the sieve plate and the bottom of the tank. These particles passing through the sieve plate are the main substances that cause turbid wort, so reflux must be carried out.

The operation procedure is: first open the valve of the wort outlet pipe at a relatively fast flow rate, so that the turbid wort flows out. At this time, it must be carefully pumped back to the filter tank (miniature equipment or can be connected to the filter tank), depending on the return flow. For the turbidity of the wort, adjust the flow rate in a timely manner until the reflux wort is clear; the reflux time is generally about 10 minutes. Then enter the wort filtration stage.