Production & Applications
Your questions answered on how smoke flavourings are made and how they’re applied to different types of food.
What are smoke flavourings?
Smoking has been a method of cooking food for thousands of years. Smoke was used for its ability to add flavour and texture and to preserve food products such as fish, meat and cheese. In the 1900s, commercial food industries developed methods to condense and use smoke in a liquid form. These substances are known as ‘smoke flavourings’ and are used to impart the same characteristics to food as conventional smoking.
Contrary to what some might think, smoke flavourings are not synthetic. Smoke flavourings are made by burning real wood and capturing the smoke cloud in water. Learn more about the International Organization of the Flavor Industry (IOFI) definition of smoke flavourings. This allows for the flavourful and functional components of smoke to be collected, whereby the harmful components of smoke, such as tars, ash and polycyclic aromatic hydrocarbons (PAHs) are separated out.
Consumers’ desire for smoke-flavoured foods, driven by the global craze for barbecue, is challenging food manufacturers to provide smoke-inspired offerings more efficiently, sustainably and cost-effectively. Smoke flavourings allow food manufacturers to keep pace with consumer demands.
How are smoke flavourings produced?
Smoke flavourings, also known as liquid, purified or condensed smoke, are produced by a thermal decomposition of wood, called ‘pyrolysis’.
At a traditional smokehouse, a smoke generator is fed wood or wood pellets which are then pyrolysed to create a smoke cloud. The smoke cloud then fills the smokehouse and interacts with the foodstuffs resulting in a smoky flavour.
To create smoke flavourings, sawdust, obtained from wood which has not been treated with chemical substances as a lumber by-product, is smouldered to create a smoke cloud. Water is then added to capture and condense the smoke. The non-desirable components of the smoke, such as the tar and creosote, are not water-soluble and, thereby, left out of the condensed smoke. This ‘purified’ smoke is then put through a filtration process to create what is known as a ‘smoke flavouring primary product’ (SFPP), which can then safely be applied to add a smoky flavouring and/or texture to food through a process called regenerated smoking.
Smoking food using regenerated smoke is defined in Regulation (EU) No 1321/2013 as treating food by exposing it to smoke, which is regenerated by atomising smoke flavourings in a smoking chamber, under time and temperature conditions similar to those for hot or cold smoking.
This process generates significantly fewer undesirable compounds than are produced by a traditional smokehouse. This means smoke flavourings are generally considered to be of less health concern than the traditional smoking process.
The Process
Step 1
Sawdust dryer
Smoke flavour creation begins with untreated, recycled sawdust from local lumber mills. The sawdust is then dried to a standard 2-4% moisture content to allow for manufacturing consistency.
Step 2
Pyrolysis
Sawdust is sent through an airlock and fed into the pyrolysis chamber. It is critical to limit oxygen and maintain specific temperatures, pressures, and times so that a specific smoke cloud is formed. The cloud is pulled via pressure into a condensing chamber. Once in the chamber, the smoke cloud is cooled to a liquid via direct contact with water. The condensing stage is critical – ensuring the collection of as much smoke flavour as possible both to reduce and eliminate emissions, as well as to get the most out of every kilogram of sawdust. At this stage, the product is condensed and considered raw or unfinished smoke flavour.
Step 3
Separation
The product is phase separated. During this time two distinct layers form, an aqueous and a non-aqueous layer. The non-aqueous tarry layer will be separated and discarded; this fraction holds the un-desirable portions of smoke. The aqueous layer will be decanted and filtered to become a primary smoke flavouring product.
Step 4
Fresh production tank
The product will go through quality checks and analysis, before being filtered one more time in accordance with food safety and material standards.
Step 5
Final Condensed Smoke
At this point the product is considered ready for use. The fractionation and purification processes in steps 4 and 5 as well as the condensing step, are the main methods in which smoke flavourings are improved vs. traditional smoking. Controlled condensing collects and preserves a higher level of functional and flavour compounds, and the phase separation and collection process allow for the removal of fly ash and tar that can be considered contaminants, create off flavours, and contain carcinogenic compounds primarily polyaromatic hydrocarbons (PAHs).
Sawdust dryer
Smoke flavour creation begins with untreated, recycled sawdust from local lumber mills. The sawdust is then dried to a standard 2-4% moisture content to allow for manufacturing consistency.
Pyrolysis
Sawdust is sent through an airlock and fed into the pyrolysis chamber. It is critical to limit oxygen and maintain specific temperatures, pressures, and times so that a specific smoke cloud is formed. The cloud is pulled via pressure into a condensing chamber. Once in the chamber, the smoke cloud is cooled to a liquid via direct contact with water. The condensing stage is critical to ensuring the collection of as much smoke flavour as possible, both to reduce and eliminate emissions, as well as to get the most out of every kilogram of sawdust. At this stage, the product is condensed and considered raw or unfinished smoke flavour.
Separation
The product is phase separated. During this time, two distinct layers form – an aqueous and a non-aqueous layer. The non-aqueous tarry layer will be separated and discarded; this fraction holds the undesirable portions of smoke. The aqueous layer will be decanted and filtered to become a primary smoke flavouring product.
Fresh production tank
The product will go through quality checks and analysis, before being filtered one more time in accordance with food safety and material standards.
Final condensed smoke
At this point the product is considered ready for use. The fractionation and purification processes in steps 4 and 5, as well as the condensing step, are the main methods in which smoke flavourings are improved in contrast to traditional smoking. Controlled condensing collects and preserves a higher level of functional and flavour compounds. Meanwhile, the phase separation and collection processes allow for the removal of fly ash and tar that can be considered contaminants, create off flavours and contain carcinogenic compounds – primarily polyaromatic hydrocarbons (PAHs).
What types of food use smoke flavourings?
Smoke flavourings are used globally to make thousands of food products including meats, poultry, fish, charcuterie, cheese, snacks and sauces. They’re a vital part of Europe’s food production industry and are used by all types of food manufacturers – from large multinational food companies to small-to-medium-sized businesses (SMEs) – to meet the tastes and nutritional demands of global and European consumers.
Currently, there are hundreds of smoke flavouring formulas that provide unique flavour, colour and texture to thousands of applications for varying palates, application techniques and food categories.
Smoke flavourings have been safely used to flavour food for decades and are approved for use in the EU.
How are smoke flavourings applied to meat, fish and cheese products?
Smoke flavourings are applied to meat, fish and cheese using a process called regenerated smoking. Regenerated smoking is a process of treating food by atomising a smoke flavour into a smoke chamber under conditions similar to those used in hot or cold smoking.
This generally involves taking smoke flavourings and loading them into a stainless-steel container. The container is then pressurised using compressed air and connected to a smoke regeneration system control unit. The smoke flavouring is then pumped through a flow meter and into an atomiser nozzle. The nozzle is designed to create a fine mist that looks and acts like a smoke cloud, which is then absorbed by the food.
Unlike traditional smoking, which can take anywhere between 1 and 20 hours, smoking with regenerated smoke only takes between 5 and 20 minutes depending on the smoke profile of the final product. This is controlled by the pressure and the flow meters connected to the system. Once the regenerated smoke cycle is finished, the manufacturer can finish cooking the product to safe temperatures and go on to package their product.
This process is known as atomisation. Smoke flavourings can also be applied to food via immersion, injection, marination, pre-treated casings, direct application via product packaging and even on contact with surfaces such as conveyor belts.
These quick and efficient smoke flavouring application cycles are more consistent for the food manufacturer, allowing for shorter cooking times, reduced emissions and less energy than traditional smoking. Controlled cycles also create less build-up and waste during the process, allowing for fewer smoke and heat emissions and less water and chemical usage during cleaning procedures.
How are smoke flavourings applied to snacks, sauces and prepared meals?
Smoke flavourings can be spray-dried, whereby a dry powder format is created. These dry formats can be added to snack seasonings, prepared meals and sauces. Additionally, liquid smoke flavourings can be added to sauces and prepared meals.