Tag Archives: beverage

A look at the Beer Brewing Process – Just in time for the Rotronic 2014 International Sales Meeting

Beer brewing in general

There is no exact date, as to when the first beer was brewed but already at the beginning of the fifth millennium BC, people in southern Mesopotamia, in a region known as Sumer (modern Iraq), were brewing beer.

Beer, like other commodities such as wheat and other grains, was used as a currency. A clay tablet, dating from 6’000 BC contains one of the oldest known beer recipes.

Beer Map
Beer consumption throughout the world

The basic ingredients of beer are: water; a starch source: which is able to be fermented; yeast: to produce the fermentation; a flavouring such as hops. Yeast is the microorganism that is responsible for fermentation. Specifically Saccharomyces cerevisiae is the species of yeast that is used for brewing.

Facts & figures:
Beer is the third most popular beverage in the world, coming in directly behind tea and water.
American beer is made mostly from rice. This was invented to give American beer a lighter taste and tap into the market of women buyers.
In the UK 28 million pints of beer are consumed every day, which equates to 100 litres per head each year.
Belgium has over 400 different beer brands.
Cenosillicaphobia is the fear of an empty glass.

There are several steps in the brewing process, which include malting, milling, mashing, lautering, boiling, whirl-pooling, fermenting, conditioning, and filtering.

Step by step brewing:
  • Malting: germination of cereal grains. The sprouted cereal is then kiln dried at around 55°C. Milling: grinding of the malted cereal.
  • Mashing: the cereals are mixed with water and then heated.
  • Lautering: separation of the mash: the liquid (wort) is separated
    from the residual grains.
  • Boiling: the wort is boiled to ensure sterility and then hops are added for flavour!
  • Whirl-pooling: the wort is sent into a whirlpool, removing the dense particles using centrifugal force.
  • Fermenting: yeast is added to the wort: conversion of the carbohydrates to alcohols and carbon dioxide – the chemical conversion of sugars into ethanol!
  • Conditioning: the tank is cooled and the yeast and proteins separate from the beer. This conditioning period is also a maturing period.
  • Filtering: the beer is filtered: stabilising the flavour.
  • Packaging: the beer is packed then to the customers
Example brewing process
Example brewing process
Why the need to measure the carbon dioxide?

Carbon dioxide Carbon dioxide (CO2) is a naturally occurring chemical compound. It is a gas at standard temperature and pressure.

We inhale oxygen and exhale carbon dioxide. The carbon dioxide level in exhaled air is rather constant: around 3,8%. When carbon dioxide is exhaled it will quickly be mixed with the surrounding air even indoors and provided that the ventilation is good, the concentration will be reduced to harmless levels. Indoor carbon dioxide levels usually vary between 400 and 1’200 ppm (parts per million). Outdoor carbon dioxide levels are usually 350 – 450 ppm.

Beer brewing process: Heavily industrialised or contaminated areas may periodically have a higher concentration of CO2. Carbon dioxide is released during the beer brewing process and as you will see below, CO2 is toxic for living organisms. In brewery environments where process generated carbon dioxide is widely present, the maximum permitted carbon dioxide concentration according to most standards is as high as 5’000 ppm (5%) during an 8 hour working period.

Beer storage: Most beer leaves the brewery carbonated: beer and carbon dioxide are sealed in a container under pressure. It can be carbonated during fermentation but it can also be carbonated in the bottle. In this case the beer is allowed to ferment completely. It is left unfiltered which leaves active yeast suspended in it. A small amount of sugar is then added at bottling time. The yeast begins to act on the sugar: CO2 is released and absorbed by the beer.

Beer can also be force carbonated, in which case it is allowed to fully ferment. Then CO2 is pumped into a sealed container with the beer and absorbed by the liquid. In this case, a tank of carbon dioxide will also be required. Undetected leaks in a gas system is a costly waste and a safety risk to personnel. While small leaks are inherent in any gas system, those of significant size raise the level of economic and safety risk.

How does CO2 affect the human body?

Due to the health risks associated with carbon dioxide exposure, there are regulations and laws in place to avoid exposure! The US National Institute for Occupational Safety and Health (NIOSH) states that carbon dioxide concentrations exceeding 4% are immediately dangerous to life and health.

In indoor spaces occupied by people: concentrations higher than 1’000 ppm will cause  discomfort in more than 20% of occupants. At 2’000 ppm, the majority of occupants will feel a significant degree of discomfort and many will develop nausea and headaches.

How CO2 affects the body
How CO2 affects the body

Case study: The lake Nyos
The lake Nyos is a crater lake situated in Cameroon. In 1986, a pocket of magma from under the lake, leaked a large amount of CO2 into the air. The result was suffocation of around 1’700 people and 3’500 livestock!

As we take beer brewing seriously we will be sure to test a number of varieties with our colleagues from the world over at the Rotronic 2014 International Sales meeting in Grindelwald next week!

Dr Jeremy Wingate
Rotronic UK

CO2 Monitoring in the Beverage Industry

The Carbonating Process

Everybody loves a refreshing sparkling drink during the summer heat. CO2 does not only bring the bracing sparkling effect into your drink but even helps to conserve the beverage. A chemical reaction of CO2 and water forms carbonic acid which has an antibacterial effect. All well known soft drinks come with the right fizz.

The beverages are treated with a carbonating process just before the final bottling or canning. Carbonating systems mainly consist of a booster pump, a CO2 saturator, a carbonating tank and an optional CO2 analyser to check the carbon acid content of the final product.

With the aid of a booster pump the beverage mixture is conveyed to the saturator which works according to the Venturi principle. An optimising control keeps the flow velocity through the saturator within a constant working range. This generates a partial vacuum at the smallest cross section of the saturation which causes a reduction of the pressure level. This suction effect then mixes the CO2 with the beverage liquid. The short-time increase of the flow velocity guarantees a fine distribution of the gas and homogenous mixing.

The process essentially depends on the tank pressure which has to be set slightly higher then the saturating pressure of a specific product. Right after that, the drink is ready to be bottled automatically to preserve its texture.

diagram

CO2 saturator in a carbonating stage of a bottling line

Why the need to monitor CO2 in a beverage plant?

Carbonating processes use most of the CO2 in the beverage industry. But beside that the gas also occurs during fermentation or it is used for refrigeration – so CO2 is omnipresent in such facilities.

High concentrations of CO2 in closed areas where workers attend to their jobs can become a lethal risk. Extensive CO2 levels can lead to bad headaches, drowsiness, unconsciousness and even sudden death. A CO2 level above 5000ppm is considered as alarming. The gas can neither be recognised by its odour nor by its visual appearance. Soft-drink factories or breweries therefore require an accurate CO2 control and alarm system to maintain their high standard of operational safety.

Capture

To assure hygienic conditions and to reduce the risks of CO2 incidents, bottling lines which fill carbonated drinks are often operated in separated areas of a factory. There is a controlled loss of CO2 during the bottling or canning process of sparkling drinks which is minimal, but the amount adds up considering that industrial lines are able to fill up to 30.000 bottles an hour. With each filling a tiny amount of CO2 gets exposed to the surrounding atmosphere.

Factories require big amounts of CO2 which is delivered and stored in gas cylinders. During transport or storage there is always the risk of a thin crack occurring and that gas escapes unnoticed. Drinks which are not meant to be carbonized such as beer or wine also emit CO2 during the fermentation process. The gas needs to be release controlled. Also here leakage can be a danger and CO2 sensors help to keep control of the atmosphere.

This small insight shows how beverage manufacturers depend on reliable CO2 monitoring systems!

Candice – Sales Support