Measures to Improve Beer Flavor Stability

During the storage process of beer, its flavor will change to a certain extent. In order to ensure its flavor, it is necessary to improve the flavor stability of beer.

Control of Oxygen Intake During Wort Preparation

1.Crushing process:

(1) The pulverization process will also bring in a large amount of oxygen. It is better to replace the air with nitrogen in the space of the pulverizer.

(2) In addition to using deoxygenated water for wet crushing, the agitation should be minimized and the mash should be conveyed gently.

(3) It is smashed immediately during production and feeding, so as to avoid smashing in advance and keep it apart for a long time.

2.Saccharification process:

(1) Use CO2 (recycler from our factory) or nitrogen as protective gas to replace the air in the pot

(2) Minimize the number of times of mash stirring and reduce the stirring speed during the saccharification process

(3) Minimize the delivery times of wheat mash, and select a pump with a slightly larger capacity to shorten the delivery time, slow at low speed, and reduce turbulence.

(4) Careful control to avoid sucking in a lot of air when pumping is complete.

(5) Pumps, seals, valves, etc. must not have any flaws, and maintenance should be strengthened.

(6) The water contains a lot of dissolved oxygen, and deoxygenated water should be used for saccharification and washing water.

(7) The delivery of mash and wort should be delivered from the bottom of the pot and tank.

(8) When the wort is boiled, the wort boiling pot should not be boiled as much as possible, and the boiling time should be properly controlled.

3.Traditional fermentation process

Oxygen intake:

After the traditional fermentation is completed and the beer is served too late, the dissolved oxygen in the beer will increase, and the dissolved oxygen can be as high as 1.5g/mL for 4 days late.

Control measures: The drinking time should be strictly controlled according to the process regulations.

4.When transport beer

Oxygen intake:

When the fermentation broth is served, if it is not handled properly, it will take in a lot of oxygen. At the beginning of drinking, take a sample at the inlet of the pump, and the dissolved oxygen is about 50μg/kg. Afterwards, it gradually decreases. When the drinking is finished, the dissolved oxygen rises again to about 70 μg/kg; the dissolved oxygen in the beer in the final tank is about 200 μg/kg. However, due to the assimilation of yeast and the oxidation of reducing substances in the beer after drinking, the dissolved oxygen in the beer will gradually decrease to about 20μg/kg. After drinking, it is best not to change the tank, otherwise, a large amount of oxygen will be taken in, and a large amount of reducing substances in the beer will be oxidized, which is very unfavorable to the abiotic stability and flavor stability of the beer.

Control measures:

(1) All joints and connections of the beer line must be tight, and the pipeline design should avoid excessive flow rate and eddy current.

(2) Carbon dioxide should be used instead of air as the back pressure; or a small amount of carbon dioxide (0.1~0.2 beer capacity) should be filled in the beer delivery process, so that the excess carbon dioxide will take away the air; but too much carbon dioxide is also disadvantageous, some Beneficially volatile substances are lost.

(3) The flow velocity of beer entering the tank should be low (<1m/s) to avoid eddy currents; if the inlet pipe diameter is increased by 50%, the inlet velocity can be reduced by 45%; it can also be used at the beginning and the end of beer delivery to reduce pumping speed.

(4) The type of tank is also related to oxygen uptake. Under normal circumstances, the oxygen uptake of the horizontal tank is 50% more than that of the vertical tank. The use of the vertical tank is beneficial to reduce the oxygen uptake.

(5) The beer pipeline should be filled with deoxygenated water before the beer is transported. Before the beer enters the pipeline, the water should be ejected with carbon dioxide. Considering that sometimes the beer will be mixed with water, the water used should be deoxygenated water, because the water Contains 8-10μg/kg of dissolved oxygen, hundreds of times the content allowed in beer.

5.Oxygen uptake during carbonation

Oxygen intake:

Filling the beer with the same volume of carbon dioxide (containing 0.05% air) will theoretically dissolve 200 μg/kg of oxygen in the beer.

Control measures:

Carbon dioxide-filled beer must be deoxygenated pure carbon dioxide, and its purity is required to reach more than 99.998%.

6.beer filtration

Oxygen intake:

When the beer is filtered, the dissolved oxygen of the first part of the filtered beer is very high, and then the intake of oxygen is reduced. If the operation is done properly, the dissolved oxygen of the whole beer is about 30 μg/kg.

Control measures:

To reduce the intake of a large amount of oxygen at the beginning of the filtered beer, the water and air in the filter and the system should be replaced with deoxygenated water first; if diatomaceous earth is used as a filter aid, the diatomaceous earth slurry should also be filled with carbon dioxide. , remove the air in the pulping, replace the air with carbon dioxide or nitrogen in the pulping tank space, and dewatering is required for pulping.

2vessels brewhouse systems with non-slip working platform

7.other measures

(1) The content of variable valence metals (such as Cu, Fe, etc.) in the raw materials, water and all additives used must be lower than the standard requirements.

(2) Pay attention to adjusting the pH value during saccharification. The mash is controlled at about 5.5, and the wort is controlled at about 5.2, which is beneficial to the stability of beer flavor.

(3) The wort filter should be clear and reduce the content of unsaturated fatty acids in the wort.

(4) The separation of hot and cold solids should be thorough, and the separation of cold solids should be preferably by flotation or filtration.

(5) The boiling strength of wort should not be lower than 8%~10%, so that some volatile aldehydes can be volatilized.

(6) After boiling, the pumping, separation of hot coagulation and cooling time of wort should be short, which should be controlled within 100min (cooling time within 60min) to avoid thermal reaction.

(7) The material of production equipment and pipelines should be made of stainless steel, and copper should not be used as much as possible.

(8) Malt drying, mashing, filtering and heating of wort, boiling of wort, pumping after boiling, and residence time of wort in the rotary sedimentation tank will all produce chemical reactions. If the product formed is not controlled, it will cause the aging taste of the beer in the future.

(9) The PU value of sterilization should not be too high, and it is appropriate to control it at 15~20PU. The temperature of the beer at the outlet of the sterilizer should be controlled below 25°C.

(10) The transportation vibration of beer, high storage temperature and sunlight exposure can easily induce the aging taste of beer. beer stored below 10°C has a lower chance of aging in a short period of time.

(11) Production and sales should be well coordinated to avoid product backlog, and the principle of first-in, first-out should be adopted for the entry and exit of finished beer.

(12) Relevant antioxidants should be added before filling the beer.