How to design professional equipment for craft beer brewing?

In this article we will discuss the main elements of equipment for craft beer production and the minimum requirements to meet brewing technology standards.

In order not to complicate the subject further, we will focus on small factories with a capacity of 250lt to 2,000lt per batch.

Nowadays, there are several configurations for the design of a cooking room, which can be summarized as follows:

1. Cooking room with separate filtering tank, of German tradition.

2. This type of design is of English tradition. In the past, a maceration of infusion used to be done by preheating the water and without further heating the pot.

Here are some examples to understand the various configurations:

Slowbeer 250 - German system

Slowbeer 500 Plus - English system

Slowbeer 250 Plus - English system

Slowbeer plus 10/20/25HL - English system

The type of equipment design mainly influences the brewing time and the quality of the wort. As can be seen in the examples, lauter tuns do not usually have a heating system, they only have temperature insulation.

The advantage of the English system over the German system is the possibility of continuous boiling, as soon as the lautering is finished and the wort is transferred to the boiling kettle, it is possible to brew a new batch in the mash kettle. This process is possible thanks to the simultaneous heating of the 2 pots.

Here are the production times for 2 consecutive processes (double cooking):

• German cooking room with 2 vats: 11 hours -> Slowbeer 250 cooking room

• English 2-tank brewhouse: 8.5 hours -> Slowbeer 250 plus brewhouse, Slowbeer 500 Plus brewhouse, Slowbeer Plus 10/20/25HL brewhouse

• German cooking room with 3 vats: 10 hours Firing room 1000

• German 4-tank brewhouse: 6 hours 40HL brewhouse

Before we get into dimensions and heating methods, here are the main components of a traditional cooking room:

1. Heated mash tun: temperature control (probe and thermostat), stirrer, lid

2. Filtering tank with double filtering bottom and accessory for washing grains

3. Boiling vat (can be the same macerator)

4. Process pump with variable speed drive

5. Heat exchanger

6. Control panel

All the elements in contact with the product must be made of AISI 304 or AISI 316 steel according to European standards. For a longer durability of the product, it is recommended to make also the supporting structure and the other components of the same type of steel. It is easy that another metal can transmit the oxidative process to a steel that is not well cared for, thus reducing the life time of the equipment.

MASH TUN

In the mash tun, the malt is mixed with hot water (from a hot water tank or heated in the same kettle) to a temperature that allows the enzymes to transform the starches into sugars and create the wort.

The hot water tank is usually at least twice the capacity of the cooking room (example slowbeer 250, 600lt water tank). The water in the tank is used for mash-in, washing and alkaline cleaning.

Some brewhouses have a hopper with a malt hydration system before mash-in, this process avoids the creation of dust (which can generate yield losses), avoids degrading the enzymes by having a too high pre-mash temperature and avoids the creation of lumps.

Water-malt ratio and volume

The volume of the mash kettle has to be evaluated considering the possible ratios between water and malt, from 1.6lt/kg for denser mashes to 5lt/kg for lighter and easier to manage mashes. In case the mash kettle is also the boiling kettle, a larger space must be considered due to the wort boiling (overboil). It is also important to point out that many brewhouses have a number in their name (e.g. Slowbeer 250) indicating the liters of wort to be brewed, this number is always related to the plate degree of the wort brewed (e.g. 250lt with plate degree 17º). Brewing beers with lower density we will obtain more liters, in case of denser beers we will obtain less liters.

Regardless of the type of heating, it is necessary to equip this pot with a stirrer that can homogenize the temperature and promote enzymatic transformation (mash yield). The stirrer must not touch the walls and bottom of the vessel to avoid crushing the cereal husks. It is advisable that the paddle speed does not exceed 2m/s. Having a speed variator on the agitator can help the process in relation to the type of macerator we have, as in the case of our Slowbeer 500 Plus.

There are 3 main mashing techniques in brewing:

Infusion mash, no need to heat the mash pot.

Stepwise mashing, the wort is brought to certain temperatures for various enzyme activities

Decoction, a traditional Central European technique whereby one third of the mash is brought to a boil and then returned to the mash pot, increasing the temperature to the next step (this process can be repeated several times).

When designing an equipment, it can be considered whether to give the possibility to work with the 3 techniques as in our Plus firing rooms.

The heating of the pot can be executed in several ways, nowadays it is a very sensitive issue due to the rising costs of gas and electricity.

The options available today are mainly 3:

1. Direct call

2. Electricity

3. Dry steam

1) The first one is the oldest one used, the flame distribution technology has improved a lot in the last years and the problems of caramelization of the wort have been partly overcome. In these types of equipment the stirrer has a fundamental task, since it avoids the burns of the skins at the bottom of the pot and that is why it has to be used continuously during the mashing process. These types of equipment are usually more economical, but they have limitations in certain contexts and alter the quality of the wort.

2) Electric equipment is divided into equipment with immersion heaters, equipment with heaters at the bottom of the pan and equipment with diathermic oil.

The first ones are not very advisable for professional equipment of this size 250/500lt, they have 2 main problems: the must caramelization/caramelization and the difficulty in cleaning.

The technology with contact resistors is applicable in small systems, less than 300lt.

The latest technology has a long history of use in the food industry and some brands use it in the brewing industry. The diathermic oil is heated in an external tank and recirculated through the jackets of the pots.

Electric equipment is recommended for beer production systems up to 500lt.

3) From 500lt upwards, the most commonly used form of heating is dry steam. Dry steam can be produced with a gas, oil, electric or pellet boiler. The steam arrives in the cooking room and thanks to a collector it is distributed to the mash and boiling pots.

It is currently the most efficient and economical form of heating, however in some situations this choice is not the most appropriate:

• When the firing rooms are small 250/500lt the cost of the boiler, steam installation, boiler room and certification can be higher than the firing room itself.

• When the size or location of the premises does not allow us to install the boiler system.

FILTER TANK

After finishing the mash, the solid part must be separated from the liquid, trying to extract as many sugars as possible without dragging the cereal husks and extracting the tannins (astringent component). The design of the filter is essential so that the flow is continuous and does not allow undissolved particles to pass through.

This part of the process is called lautering and consists of 2 parts: filtering by recirculating the wort through the grains (the first wort is obtained) and washing the grains(sparging) to extract as many sugars as possible (the second wort is obtained). When the operation is carried out in a dedicated pot it is called lauter tun, if it is carried out in the same mash pot it is called mash filter.

The diameter of the lauter tun must be large enough to distribute the wort flow over the whole double-bottom, normally the height of the grain bed does not exceed 50cm. A false bottom is positioned a few centimeters above the bottom of the pot, usually made by water cuts of 0.7mmx80mm that occupy 10% of the total surface of the filter.


Some pots are equipped with lag-cutting paddles that favor the flow of the wort.

The wort is recirculated until it is clean, producing a clean wort means obtaining a more stable beer with more defined flavors.

The recirculation is done through a spray arm that may have one or more terminals such as plates, perforated balls or other diffusers.

Once the clean must is obtained, water at a temperature between 71 and 78ºC is added through the same spray arm. Adding water with a "shower effect" avoids the formation of preferential channels.

During this phase of the process it is important to always leave the grain bed covered to avoid excessive oxidation.

Filter vats usually have a rectangular manhole for bagasse discharge.

BOILING VAT

The boiling vat must have a volume large enough to contain the amount of pre-boiled wort, plus extra space for overboiling.

In this part of the process the must is brought to 100º with the following objectives:

1. Isomerization of alpha acids

2. Must sterilization

3. Deactivating enzymes

4. Coagulate and remove proteins

5. Evaporation of volatile defects

In the smallest equipment, the boiling vat is equipped with a tangential inlet for whirlpooling, a clarification technique that generates a centripetal force by accumulating the heavier bodies (proteins, polyphenols and other poorly soluble compounds) in the center of the pot. The clarified must is extracted from the side of the vat by passing through a heat exchanger.

The ways of heating the boiling pot are the same as for heating the mash tun with open flame, electrically or with dry steam. In case of steam or diathermic oil jackets an asymmetric design of the jackets is advisable to favor convective movements, it is advisable to apply the jacket.

PROCESS PUMP

The process manifold pump is one of the main elements of the system, it is advisable that the parts in contact with the must are made of AISI 316 steel, that it has a frequency variator to be able to set the speed at each stage of the process and that it is resistant to high temperatures.

The pump is used for transfers from one pot to another, for whirlpooling and for sending the wort to the fermenters.

HEAT EXCHANGER

In equipment of this size, a plate heat exchanger is usually installed. The cooling system is composed of several plates that favor the thermal exchange between the hot wort at 100º and the cooling water.

There are 2 types of plate heat exchangers:

• 1 stage, exchange between wort and water coming from the network or from a cold water tank. (Example. Wort cooling 100ºC -> 18ºC, Water heating 13ºC->83ºC)

• 2 stages: Stage 1, exchange between wort and water coming from the network or from a cold water tank. (Example. Wort cooling 100ºC -> 20ºC, water heating 13ºC->85ºC). Stage 2 exchange between wort and glycol (Example: Wort cooling 20ºC -> 7ºC, Water heating 1ºC->13ºC).

CONTROL PANEL

The various processes can be controlled from the control panel:

• Temperature control

• Stepwise maceration programming

• Activate the pump and control its speed

• Activate the agitator

• Start a production cycle

The more technologically advanced equipment can control other parameters as well as interact with the water tanks.

The design of brewing equipment can be tedious, especially when it comes to defining dimensions, volumes and energy transfers.

One of the aspects most recognized by our customers is the performance of our equipment(brewhouse efficiency), which is around 90% depending on the recipe.

We will discuss this concept in more detail in another article in the Processing category.

Here are the European standards that our brewing machinery complies with:

• Directive 2006/42 EC Machinery Directive

• Directive 2006/95 EC Low Voltage Directive

• Directive 2004/108/EC Electromagnetic Compatibility

• Standard UNI EN ISO 12100-1:2005 General principles for design

• Standard UNI EN ISO 12100-2:2005 General principles for design

• UNI EN ISO 13857 Machinery Safety Standard

• Standard UNI EN ISO 13849-1:2007 General principles for design

• Standard EN 983: Safety of machinery

• Standard EN 60204: Safety of Machinery

• Standard EN 294

• Standard EN 50081-1

• Standard EN 50081-2

• ISO Standard 3744

• ISO 11201 -1-2

• EEC Standard 89-336

• Standard EN 953

• Standard EN 954/1

• Standard EN 61000

At Slowbeer we have been designing microbreweries for more than 20 years and we have reached a level of development that meets our expectations, making various types of equipment from the simplest ones such as the Slowbeer 250 to the more developed Slowbeer 500 Plus Slowbeer 500 Plus.

We continue to implement our equipment to provide brewers with new tools, improve thermal performance and energy savings.

Cheers!