Coldsmoking - is a low temperature process of flavouring or preserving food by exposing it to wood smoke. Meats and fish are the most common smoked foods, though cheeses, vegetables, and ingredients used to make beverages such as whisky and lapsang souchong tea are also smoked.
In Europe traditional smoking woods like Oak, Beech, Alder and fruit woods like Apple and Cherry are commonly used. In North America, alongside some of the European woods they also use more exotic woods like hickory, mesquite, pecan, and maple. We have a page dedicated to the flavours and aromas derived from the smoke
Cold smoking temperatures should typically be maintained below 30°C/86°F. We recommend using a much lower temperature than this as food has a tendency to degrade when held at elevated temperatures for a long time. Holding raw meats and fish at ambient temperatures for long periods of time is not good food safety practice and therefore, before meat and fish is cold smoked it usually undergoes a curing or salting process.
Food will not cook when it’s in a cold smoker but will be bathed in cool smoke and will take on a rich, smoky flavour. If smoked for long enough food will develop a rich colour. Cold smoked fish tends to retain a relatively moist texture because it goes through a brining process before going into the cold smoker.
Coldsmoking was originally one of the methods used to preserve food before mechanical forms of refrigeration were invented. By using the naturally occurring compounds in the smoke to extend the food's useful shelf life, food could be made to last through lean times. We now know that there are special chemicals in smoke that possess anti-bacterial and anti-microbial properties. Even though we have excellent refrigeration these days, we still enjoy smoke flavour on our food. It’s become part of our food history and culture.
Cold smoking is easy to do and can be achieved without the need to spend lots of money on fancy equipment. To cold smoke food, the first thing you will need to do is make sure you have an enclosure to hold the food. As you will be operating at low temperatures the material used for this enclosure can vary from cardboard through to wood or metal.
You’ll need to consider how you intend to smoke the food, whether you hang the food from hooks or if you think placing it on food racks is going to be better for you. This largely depends on what you are looking to cold smoke. An good example of how this can vary can be shown when it comes to smoking fish. I tend to lay my salmon on racks when it goes in the cold smoker as I can get many more salmon sides in the cold smoker this way. When I smoke kippers though, I prefer to hang them on tenter hooks. When smoking cheese its preferable to use food racks, arranging the cheese to maximise space in the smoker.
When I cold smoke Olives, sun dried tomatoes and other vegetables that have a lot of oil on their surface, I tend to arrange these foods on metal trays so they don’t drip oil everywhere. Maximising space in the cold smoker is important to ensure you get the most out of it.
Cold smoking different food in the same smoker is perfectly ok. Working at ambient temperatures means the flavours and aromas of the food don’t cross over.
Generating smoke requires combustion or pyrolysis to take place. One of the by-products of these processes is heat. In order to cold smoke we need to either control the amount of heat produced or find a way of removing the heat from the smoke. By using a proprietary cold smoke generator you have a device which can combust wood dust in a very controlled way in order that it doesn’t produce enough heat to affect the environment you are smoking the food in.
Smoke generators come in many forms. One popular type of smoke generator is the maze style cold smoke generator. These smoke generators limit the availability of the fuel (wood dust) that can be combusted at any one time. Constructed of a light wire frame and clad with fine wire mesh, they tend not to draw heat away from the point of combustion and allow air in from all sides to aid combustion.
In a maze smoke generator, the wood dust sits within a narrow channel where smouldering is limited to a narrow strip of just over a centimetre. The advantages of these types of smoke generators is that they use very small quantities of wood and burn for a long time. Typically, the small version of the ProQ cold smoke generator uses a little over 100g of dust and smoulders gently for between 6 to 8 hours on one charge. The larger version of the same cold smoke generator uses more dust (250g -300g) but smoulders for up to sixteen hours. It produces a little more heat as the burning channel is a little wider but it’s designed for a slightly larger cold smoker so any excess heat is easily dissipated in a larger volume smoker.
Some other methods of generating smoke can produce a large amount of heat. Especially when burning a quantity of wood chunks or shavings or when using a heat source to combust wood. Under these circumstances you’ll need to think about methods of removing the heat from the smoke before it reaches the cold smoker. This is usually achieved by separating the smoking compartment from where the smoke is being generated by using a pipe of channel allowing the smoke to pass through into the smoker.
Controlling the amount of heat that gets into the smoker can be done in a few ways. Firstly, by controlling the fire by limiting the availability of fuel or oxygen. And secondly, by extending the travel distance for the smoke, allowing it time to lose heat. It’s possible to combine both methods for optimum control over the whole process. It’s just these factors I cover on my food smoking course. From experience, this area of food smoking tends to cause most of the issues.
Heat in the cold smoker can come not just from the smoke but from the sun too. On warm days heat from direct sunlight can cause the temperature inside the smoker to rise beyond the mac (30C). Making sure the smoker is in shade is an important consideration and it’s one that you should think about when positioning the smoker before smoking anything. Remember, as you are likely to be smoking food for quite a long time, think about where the sun is likely to be later in the day so you don’t end up with shade in the morning and sun later in the day. If the temperature during the day is too high for cold smoking, consider using the smoker at night when the temperature is lower, and you won’t have any concerns with heat from the sun.