Wort Boiling Technology

Wort boiling is a key step in the beer brewing process. This process has a significant impact on the properties of the final product.The wort boiling operation technology involves many issues such as boiling time, boiling strength, hop addition, additives, wort concentration, pH value, and the composition of the finalized wort.

Contents hide

1 Dissolution and Transformation of Hop Bitterness

2 Formation and isolation of coagulable protein-polyphenol complexes

3 Evaporate excess water so that the wort reaches the specified concentration

4 Sterilize the wort

5 Completely destroy enzyme activity and fix wort components

6 Wort color rise

7 Increased wort acidity

8 Formation of reducing substances

9 Changes in Dimethyl Sulfide (DMS) Content in Wort

10 Saccharification pot heating form

Boiling time

After the wort enters the boiling pot, it starts to heat up for boiling. , the boiling time is calculated after the wort temperature reaches 100°C. Of course, the boiling time of wort should be determined according to the variety, process, and quality requirements of beer. prolonging the boiling time is beneficial for protein coagulation and precipitation, improving hop use rate, and the formation of reducing substances, but it is not good for foam performance; prolonging the boiling time will not only consume a lot of energy but also reduce the quality of the wort. The boiling time is generally 70-90min.

boiling strength

The boiling process is divided into three stages – preheating, initial boiling and boiling.
（1）preheat：Start preheating after the filtered wort has passed the heater surface (or heating belt), and the amount of steam now is smaller. The purpose of the preheating process is to prevent the temperature of the wort from cooling down during the filtration period so that the temperature will drop. Or preheat with hot water through a thin plate heat exchanger.
（2）initial boiling：The wort is near the early stage of boiling, and the initial boiling time should not exceed 30 minutes. The steam volume at this stage has not been opened, and the steam volume is not very large. The tank washing process is still going on in preparation for evaporation. Once the tank is washed, it can immediately enter the boiling evaporation stage.
（3）boiled：The amount of steam at this stage is opened to the most so that the wort is kept boiling . The quality of boiling has a significant effect on the coolness and settable nitrogen content of the wort.

Boil Strength CalculationBoil strength is the percentage of evaporation per hour of the blended wort. The boiling strength is generally between 8%-12%. This needs to be determined according to the material of the equipment, the heating form, the heating area, and the requirements of the type of beer.

The effect of boiling intensityHigh boiling intensity is conducive to protein coagulation and precipitation, and can remove some bad flavor components. Shorten the wort boiling time, improve the hop use rate, and ensure that the final wort is clear, transparent and of good quality. The boiling intensity is too high, and the vigorous tumbling will also strengthen the oxidation, which will change the color of the wort and reduce the reduction type. It will also lead to increased hop oil volatilization loss and insufficient hop aroma.

Changes during wort boiling

Dissolution and Transformation of Hop Bitterness

Since alpha-acids are insoluble in cold wort, hops are added when the wort is boiled to isomerize the alpha-acids and convert them to iso-alpha-acids. Iso-alpha-acids are dissolved in the wort, thereby improving the use of hops. During wort boiling, only 1/3 of the alpha-acids are converted to iso-alpha-acids.After the wort is boiled, some bitter substances are precipitated. So, the loss of this part should be considered when adding hops.

Formation and isolation of coagulable protein-polyphenol complexes

Condensed tannins in polyphenols combine with proteins in boiling wort to form flocculent thermal coagulum precipitation; non-tannin compounds remain in the wort, and together with cold coagulum, cause beer abiotic turbidity. Hops contain 0.5-2.0% hop oil. Of these, 75% are terpene hydrocarbons and 25% oxygenates. When the wort is boiled, most of the essential oils of hops are volatilized with the evaporation of water vapor. The longer the boiling time, the more volatilization, so the aroma hops should not be added too early. coagulated complexes are complexes formed by protein and polyphenolic substances and complexes composed of protein and polyphenolic oxides, which do not dissolve when heated and separate in the form of coagulum when the wort is boiled. These flocs formed by the coagulum should be separated as much as possible. Cold-setting complex is a complex formed by protein breakdown products and polyphenols in the wort. When the wort is boiled, it exists in a dissolved form; when the wort is cooled, it separates in the form of a cold coagulum.

Evaporate excess water so that the wort reaches the specified concentration

wort is boiled, the water evaporates, and the specified concentration increases . The traditional wort boiling is carried out under the condition of normal pressure 100 ℃. The quality of wort boiling is based on the tumbling degree and chia strength of wort in the boiling pot as the evaluation standard. Protein denaturation and agglomeration can be promoted if the hourly evaporation reaches 8-10% of the hot wort volume. So the degree of coagulum formation depends on the boiling intensity.

Sterilize the wort

Sterilize the wort: Since the wort contains various harmful bacteria, if it is not sterilized, it will lead to rancidity of the wort. So, the various microorganisms in it can be killed by boiling the wort.

Completely destroy enzyme activity and fix wort components

By boiling the wort, the enzyme system that is still active in the wort can be destroyed, thereby fixing the components of the wort.

Wort color rise

Due to the oxidation of the melanoidin and polyphenols formed during the boiling process, the color of the wort increases. The chromaticity of the final wort is higher than the chromaticity of the finished beer color.Because the yeast cross-adsorbs a large amount of pigment during the fermentation tank in the fermenter, the color of the beer becomes lighter and lighter.

Increased wort acidity

During the boiling process, the pH value of the wort decreases by about 0.2-0.4, and the decrease of the pH value is conducive to the precipitation and precipitation of globulin, and reduces the dissolution of hop pigments. The acidic melanin and hops formed during boiling bring in acidic substances that will increase the acidity of the wort. The pH value of the full pot of wort is 5.8/-5.9; the pH value of the finalized wort is 5.5-5.6. When the pH value of the wort is lower, the bitterness of the hops is more delicate and pure; and the hygiene and safety of the beer can be improved. A lower pH value will lead to a decrease in the use of hops, and the number of hops added during boiling will be increased.

Formation of reducing substances

Through the Maillard reaction, the amount of reducing substances such as melanoidin, dilute alcohols, and dimer alcohols in the wort increases.The reducing substances in wort can generally be divided into two categories, one is reducing polyphenols, which are slow-acting reducing substances; the other is Maillard reaction products, which are fast-acting reactants. These reduced compounds have a strong counteracting effect on oxygen , increasing the antioxidant capacity of the wort.

Changes in Dimethyl Sulfide (DMS) Content in Wort

Wort and beer both contain dimethyl sulfide to varying degrees. Dimethyl sulfide is a volatile sulfur compound that can give the beer an unpleasant odor. Remove as much dimethyl sulfide from beer as possible. The taste threshold for DMS is approximately 50-60 μg/L . Dimethyl sulfide is produced by inactive dimethyl sulfide precursor S-methyl methionine in malt, and the amount is related to barley variety, malting method, and roasting temperature.

Craft Beer Equipment Boiler

The beer boiling process is completed in the boiling pot. The boiling pot is used for the boiling of wort in beer production. etc. composition. The boiling pot (copper; wort kettle; wort cooker) is a device used for boiling and concentrating wort in beer production so that the wort reaches a certain concentration, and the wort hop aroma is brought to the wort by adding hops. It is a kind of equipment in the saccharification process. One of the main equipment. The types of boiling pots are classified according to the heating method:

heated boiling pot
Jacketed steam boiler
Electric heating tube boiling pot
Boiling pot with a built-in heater

Saccharification pot heating form

Electric heater heating: The initial investment cost of electric heating equipment is low, the operation is simple and easy to learn, and it is suitable for small beer brewing equipment 100L-500L; Many heaters can be controlled , which is convenient to control the overflow when boiling.

Burner direct fire heating: Direct fire heating equipment is a traditional heating method. A separate combustion chamber is configured at the bottom of the boiling pot as a heating area, and burners are used for heating. Direct fire heating generally requires a stirring device to prevent the pot from sticking. Generally, burners The power can be adjusted within a certain range, and it is very important to choose a burner with appropriate power. It is one of the preferred choices for customers in the Americas.

Steam heating method: The heating effect of steam heating is more stable, and the beer tastes good. The area and position of the jacket should consider the boiling requirements. Consider the independent control of the bottom jacket and the barrel jacket, or even consider dividing the barrel jacket into two. It is convenient to adjust the boiling intensity and use different jackets during mashing. At the same time, the bottom jacket can be used alone to heat the wort when there is little wort, saving the wort boiling time.

Internal heater type: When the wort is boiled, the wort is heated and boiled upward through the tubes of the heater from bottom to top. An umbrella-shaped overflow prevention cover is installed above the heater, so that the rising wort can be distributed to the surrounding, and at the same time, the formation of foam can be avoided, and the wort can be heated .

Technical advantages of internal heating boilers： (1) Less investment in equipment, no maintenance and no wear and tear. (2) Low power consumption. (3) The heat radiation loss is small. (4) The boiling temperature and evaporation rate can be adjusted. (5) It can be heated with low pressure saturated steam (0.1MPa). (6) The flow rate of wort in the inner heater tube bundle is low. (7) The equipment is simple and does not must external heaters and stirrers. Disadvantages of Internally Heated Boilers： (1) It is difficult to clean the inner heater. After each batch of production, a major cleaning is required, which will delay production. (2) Because the flow rate of the wort in the tube bundle is low, if the steam temperature is too high due to poor control of the steam pressure, local overheating of the wort will occur, resulting in darker wort color and worse taste, thus affecting the finished beer. the quality of. The choice of the heating method of the beer equipment boiling pot can be selected according to the budget, equipment volume, local electricity and gas costs, and the heating method that suits you. MICET can provide professional boiling pot design, which can better realize the boiling function, improve the boiling efficiency, and affect the taste of beer. We can also recommend a suitable combination of saccharification boilers according to the customer’s brewing process needs.

Get a turnkey solution for craft brewery equipment

If you are planning and ready to open a brewery, you can contact us. Micet Craft engineers will provide you with a list of craft brewery equipment and associated prices. Of course, we can also provide you with professional turnkey brewery solutions, allowing you more time to focus on brewing great beer. Micet Craft looks forward to working with you!!

Beer Brewing Equipment

Beer Brewery Equipment Manufacturer The brewing supplies provided by Micet Craft can support your brewing needs from small batches of micro beer brewing equipment to 100 barrels capacity. Micet Craft has reached cooperation with many breweries around the world, we can design and manufacture professional brewing systems for breweries, including cellar beer brewing equipment and other

Fermentation Tank

China stainless steel fermentation vessels manufacturer The fermentation tank is where the beer carry out the fermentation process, it provides a place suitable for life activities and metabolism for microorganisms. To adapt to the use of different sizes of breweries, Micet Craft produced a variety of sizes and specifications of fermentation tanks. Customers can choose

Bright Beer Tank

Professional bright Beer tank manufacturer from China The bright tank is a vessel for storing and carbonated beer, it is also called the brite tank. The bright tank is an important part of the workflow of professional beer brewers. It can be used to store and carbonate beer, thus eliminating the trouble of cleaning beer

Brewing Equipment

China brewing equipment manufacturer and suppliers Micet Craft has cooperated with breweries in many countries around the world to provide them with brewing equipment. We provide customers with turnkey brewery solutions, which include designing, manufacturing and installing customized breweries. The Micet Craft team has decades of experience in the manufacturing of brewing equipment, we not

Can regular dish soap be used to clean brewery equipment?

Brewhouse Equipment

Best brewhouse equipment manufacturer from china Brewing good beer requires brewhouse equipment. Whether you are brewing beer for home, business or brewery, Micet Craft can provide a turnkey solution according to the daily output you need. We have brewhouse equipment with 2 vessels, 3 vessels and 4 vessels, the unique design allows you to do decoction

Beer Filling Machine

Professional beer filling machine manufacturer Beer filling machine is the core equipment of the beer production line. Our beer filling system uses stainless steel as the production material. Stainless steel is not easy to wear, and it is easy to clean. Micet Craft provides you with a cheap and efficient way of filling beer. We

Beer Brewing System

Best beer brewing system manufacturer from china Micet Craft is a professional beer brewing system manufacturer in China. We mainly produce high-end customized turnkey brewing systems. Whether you are planning to open a nano-brewery, microbrewery, or commercial brewery, we can provide you with the most complete turnkey solution. Our beer brewing systems are all price-competitive