factsheet

food smoking

what is it?

Food smoking is an ancient method of preserving food using wood smoke. It is believed to be almost as old as the use of fire itself. When prehistoric people hung the surplus meat or fish they had caught after a successful hunting or fishing trip from the ceiling of their cave to protect it from vermin and contamination, they would have noticed that the meat exposed to the smoke of the fire stayed edible for longer. If washed with sea water prior to drying and smoking, it would have lasted even longer because of the preserving properties of the salt.

When humans started farming, food smoking was one of the few methods of preserving farmed meats for long periods. Smoke houses started to appear on farms, slightly apart from the main building – due to the smoke, and the fire risk.

There are many products on the market that have been treated with smoke flavours to make them resemble genuinely smoked foods, that can be sold for higher prices. This practice has nothing to do with real food smoking and is banned in some countries, although it is common in the UK, the US and Australia.

Smoked food is usually meat, sausages, fish or cheese, but can also include eggs, vegetables and nuts.

See 'what can I do?' for modern methods of smoking.

what are the benefits?

The main benefit is that it is a form of food preservation using a renewable resource, with the added benefit of improving flavour. So for example, before electricity, a smallholder could kill a pig, smoke the hams and make cold smoked sausages, and they would keep until the next pig was killed, 6 months later. This can still be done today, and not only will the meat be preserved without the need for refrigeration, it will have a wonderful smoked flavour too.

We've only recently discovered that wood smoke contains compounds such as phenols that inhibit the growth of microbes that cause food to spoil. Also, the salt, which is used to cure or brine the produce prior to smoking, draws the water out of the cells of the bacteria and kills them. In developed countries, where fridges, freezers and E numbers can preserve foods for very long periods, the improvement of the flavour through smoking is often more important than the preserving properties of the smoke.

In recent years, food smoking has been part of a revival of old crafts and traditional foods, and an increase in food awareness – people want to know the ingredients of the food they are eating. The trend is towards high-quality, 'slow food', with local, natural ingredients free from chemical additives.

For farmers, smallholders, hunters and fishermen, smoking is a way of making use of large amounts of meat or fish at certain times of the year. For others it is a way of increasing their range and adding quality and value to their products, which is what an increasing number of customers demand.

Cold smoking (see below) is the method used for preservation. Cold smoked meats are ideal to take travelling as they don't go off. Fish can't really be preserved for long periods, but with hot smoking, fish can last a few days longer – although the real motive is to improve the flavour.

what can I do?

cold smoking
Cold smoking is often referred to as 'real' smoking. The temperature is usually lower than 32°C and the smoking time is long - from several hours up to 3 weeks. The smoked product is still 'raw' after cold smoking, e.g. Parma Ham or salami. Many cold smoked foods have to be cooked prior to eating. Food needs to be cured before cold smoking.

hot smoking
Hot smoking applies smoke with temperatures of more than 70°C. The smoking time varies from minutes up to a few hours. It's almost barbequing - hot smoking 'cooks' food, e.g. hot smoked trout or smoked kippers. Prior to hot smoking, food is often cold smoked for a period of time to support the drying process and enhance the flavour.

wet and dry smoking
For wet smoking, put a bowl of water in the smoker to keep the food moist. This is exactly what you don't want if you are cold smoking for preservation however – you want the food as dry as possible.

barbeque smoking
Currently there is a trend for 'barbeque' smoking in America, which uses barbeques with lids or specially designed smoke barbeques. The method is the same as hot smoking, except that there is no period of cold smoking. It's a flavour-enhancing cooking method, and not anything to do with preservation.

curing
Curing is rubbing the food with salt (dry curing), or soaking in salt water (brining or wet curing). After curing, the food is washed and dried before smoking.

buying / making smokers
You can buy smokers – but they tend to use an electric element or gas to light the sawdust / wood shavings and keep them lit. From a low-impact perspective, it's better to make your own smoker – and it's very simple. All you need is a metal cupboard (or filing cabinet, or even a wooden cupboard), some hooks for hanging the food, or racks for cheese etc, a metal tin at the bottom for holding the wood shavings, and some way for the smoke to escape. One of our course tutors has smoked food using an oil drum with a hole in the top over a fire pit.

wood shavings
Find a local wood-working workshop and ask them. It has to be hardwood, and not treated – so furniture makers are ideal. Softwoods contain resin, which produces nasty tasting soot. Or you can buy hardwood shavings. A typical cold smoking uses 50g of shavings a day, so a little goes a long way.

methods
Just to give you a general idea – look at books for more detailed recipes.

meat
Preparation: depending on the meat, you can dry cure or marinade with salt/brine (up to 200g salt per kg of meat) plus a range of other ingredients such as sugar, molasses, beer, berries, pepper, cloves etc, and leave for a few days to a few weeks. Then rinse, dry and hang for a day or two.
Smoking: cold smoke for a day or two, then wrap in muslin and hang in a cool, dry place out of sunlight.

trout
Preparation: dry cure - 5–10g salt per 100g fish, bay leaves, juniper berries (and some sugar if you want). Curing time by weight: 200g – 2 hours; 300g – 2½ hours; 400g - 3¼ hours. After curing, clean and dry fish.
Smoking: cold smoke for 2 hours. Then hot smoke for 1–1½ hours at 80-85°C. Eat hot or let it cool down until the juices stop running.

cheddar cheese
Preparation: cut into cubes of around 4cm x 4cm x 4cm. This will prevent excessive cracking as the cheddar gets drier in the smoke. Curing/salting is not necessary as the cheese already contains salt from the cheesemaking process.
Smoking: cold smoke for 2 hours; eat or store wrapped in kitchen foil in a dry, cool place.