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  1. Since getting a pellet smoker I've been searching for suppliers of smoking pellets here in the UK. Found a place in Liverpool (just on the doorstep) which do very well priced bags of Lil Devils Pellets (imported), though I've yet to fire up the pit and try them so can't comment just yet. Also tried the Perfect Mix stuff from Amazon. Results were good but price wise compared the lil devils were a touch spenny. Edit - The following table lists a selection of the most common Pellet brands and suppliers in the UK as of June 2020. Please feel free to respond with anything you manage find and I'll add the data to the table!
  2. Evening everyone, I hope you’re all well during this current pandemic. I have been watching and dribbling over bbq and smoking videos a lot lately and just saw a video by Bon Appetit where they claim Franklin’s BBQ in Texas is the best in the world. Where is the best you’ve ever had? Why and what made it great? My favourite was Central BBQ in Memphis but I’ve had a lot of others that I felt are quite close.
  3. I've had some success curing & smoking my own bacon over the last few months (both streaky & back) using a couple of different cures (one fairly plain with juniper, bay, pepper) and one sweeter with maple syrup but I'm always interested in finding new and unusual cures & smokes to use. Has anyone got anything a bit left-field that they can share that works well? I've mainly smoked in cherry and maple.
  4. Hi everyone, I'm new to this forum I love BBQ and smoking. I've currently got a leg of lamb cooking on the egg smoking over olive wood😋 can't wait till it's done.
  5. Hi Everyone, New to the group, first post, etc, etc. I have a bit of experience of outdoor cooking and bbqing. I have a home made rocket stove bbq and a paving slab pizza oven which I use on a regular basis. I'd like to have a go at smoking, but having read quite a bit, I'm more confused than ever! Ideally I would like to hot smoke using wood as my heat source as well as the source of the flavour, rather than using loads of charcoal that I can't really afford. Is this possible? If it is what sort of smoker should I be looking at? I was on the cusp of getting the Azuma BBQ smoker, and then I read about reverse flow offset smokers and about how much better they are than normal offset smokers. I'm still not sure why they are better, but I am very impressionable and easily swayed! I don't have the sort of money the reverse flow cost. If I got the Azuma, or similar, could I add an extra plate as per the reverse flow ones? Any advice, suggestions, links, etc, gratefully received. I am in the UK if that makes a difference. Cheers Nick
  6. To begin the Smokevember month here is an explanation of the roles of the different processes used in curing and preserving. Everyone who cures, smokes or preserves food will use a combination of these methods, often without realising why. When you first begin curing food it can be quite stressful to know whether, what you have just created, is safe for you or your family to eat. However, with even a basic understanding of what you are doing will help you to eat with confidence. The saying "If in doubt chuck it out" is generally good advice, however this can often lead to food that is perfectly safe to eat being thrown away. Fitstly, the more you understand about the processes the less doubt you will have and therefore the less that will be "chucked". Secondly, there are a lot of people who cure and preserve food regularly who are here and can offer you advice. I would therefore recommend that the advice be updated to "If in doubt ASK before you chuck it out" What is curing when applied to food? Curing is a method of preserving food to prevent spoilage. It refers to various preservation and flavouring processes, especially of meat or fish. Spoilage can be prevented (or delayed) by using several processes. Most curing processes involve applying a combination of these to achieve the desired taste, texture and storage time. Sometimes the extended storage time is only measured in days (as in traditional smoked salmon), weeks (as in dry cure bacon) or months/years (as in jerky, salamis and Palma/Country style hams) The different processes that can be used in combination: Reducing available water – including dehydration The growth of bacteria and bacterial spores is significantly affected by the availability of water in their surroundings. Water is also required by the natural enzymes in foods that cause autolysis – the self-destruction of cells by their own enzymes. If the water is removed or made unavailable, the storage life of most foods will be prolonged. Although we could totally remove the water from the food to have the preservative effect, it only really needs it be made unavailable to the spoilage organisms/enzymes. This can be done though several different processes. Removing the water – This is often achieved by warming the food in a relatively dry environment which enables the water in the food to evaporate. The smoking process is a good example of this, where the air that includes the smoke passes across the surface of the food causing the water to evaporate and pass out of the chamber with the smoke. This is why is us usually important to maintain good air flow through your smoker when cold smoking. Changing the state of the water – For bacteria to utilise water it must be in liquid form. One of the effects of placing food into a freezer is that it changes most of the water into ice and therefore make is unusable by bacteria. Freezing, however, does not remove liquid water completely as even when frozen some of the ice will be transitioning from solid to liquid and then back to solid. The lower the temperature in the freezer the less water there will be in liquid form at any point in time. Removing water from the bacteria cells – This is done by increasing the amount of salt and/or sugar around the bacteria, causing the water within their cells to be drawn out by a process called Osmosis. The removal of water from the cells prevents the bacteria from metabolising and growing and often results in their cell walls rupturing and the bacteria being destroyed. Binding the water – Various substances, including sugar, will chemically bind large quantities of water to their molecules and will therefore make it unavailable to the bacteria. This process is one of the important steps when making a BBQ sauce or ketchup that is not going to be eaten immediately. There is still water within the sauce so that it remains pourable, however much of it is bound to the sugars that are also present and which become more concentrated as the volume of the sauce is reduced through simmering. As you can see, you do not need to physically remove the water from the food to have a preservative effect - You just need to make it unavailable for any spoilage organisms to use. Jargon alert: The available water in food is known as Water Activity (aw) and to totally inhibit most spoilage bacteria and moulds an aw of 0.8 or below is required. Many commercial food processers will use an (aw) meter to check that their products are safe for long storage, however these are very expensive and are outside the pockets of most home curers. Even though most home curing processes will not achieve an (aw) of 0.8 or below, there will still be a preservative effect, though more limited, at higher (aw) levels. Increased Salinity – adding salt Salt is usually added in one of three ways – applying directly to the outside (Dry Brining), applying as a liquid solution (immersion brining or injecting), adding salt as an ingredient. There are several ways in which salt will inhibit microbial growth. The most notable is through osmosis, or dehydration (see above). Salt’s other antimicrobial mechanisms include interference with a microbe's enzyme activity and weakening the molecular structure of its DNA. When used as an effective bacterial inhibitor it requires salt solutions of ~10% to make most food spoilage organisms inactive, however salt at this concentration in our food would be unpalatable. Lower salt concentrations will also reduce bacterial growth but to a lesser extent. Many bacteria are very hardy organisms though and as salt concentrations fall the activity of many will again begin increase. The ways of applying salt through the differing curing methods will affect the storage time of the final product. A good example is the difference between Dry cured and Immersion cured bacon. Both methods can be used to produce an end product that contains 2.5% salt, however the resulting shelf life of both methods is very different. Unsliced Dry cure bacon can be safely stored refrigerated for up to 6 weeks whereas the equivalent safe storage life for immersion cured bacon is only 2 weeks. One of the reasons for this is the levels of salt that the bacteria are exposed to during the curing process. With Immersion cure bacon the levels of salt in curing solution will depend on the volume of immersion cure being used and the weight of the meat however it will usually not exceed twice the desired end concentration – therefore will rarely exceed 5% (and will frequently be lower when using larger volumes of cure solution). Although this will inhibit the growth of most bacteria it will not inhibit it completely. When Dry curing bacon you are applying crystalline salt directly onto the surface of the meat – where most of the bacteria will be present. As this salt dissolves in the water from within the meat it results in the surface bacteria being exposed to a saline solution of 100%. As the salt diffuses towards the middle of the meat this concentration will reduce however during normal curing times the surface brine concentration is unlikely to fall below 10% until the salt concentration in the meat is fully equilibrated. Another difference between the two curing methods is that the process of immersion curing will result in an increase in the water content of the meat by about 10%, whereas the process of dry curing will decrease the meat water content. Commercially the levels of salt in brining solution will be measured using a saline meter. These are fairly inexpensive and are often affordable by the home preserver. The electronic salt meters are best as they measure the salt through its ionic properties. Another common saline meter is an optical refractometer. These should ONLY be used for saline solutions that do not also contain sugars, as the presence of sugar will make the resulting "salt" readings highly inaccurate. Increasing sugar Sugar will have a similar osmotic effect on the bacteria cells as salt, causing them to dehydrate, however sugar molecules will also bind water molecules lowering the (aw) and making them unavailable for the bacteria to use. Sugar may also provide an indirect form of preservation by serving to accelerate accumulation of antimicrobial compounds from the growth of certain other organisms. Examples include the conversion of sugar to ethanol in wine by fermentative yeasts or the conversion of sugar to organic acids in sauerkraut by lactic acid bacteria. Increasing acidity (decreasing pH) Increasing the acidity of foods, either through fermentation or the addition of weak acids, has been used as a preservation method since ancient times. In their natural state, most foods such as meat, fish, and vegetables are slightly acidic while most fruits are moderately acidic. Only a few foods such as egg white are alkaline. Generally most food spoilage bacteria thrive within a narrow pH range and as you move away from this range they become increasingly inhibited. The effect differs though between organism. For example, a pH of 4.6 is sufficient to control most spore forming organisms (e.g. C. Botulinum) however a pH of 4.2 is required to control other vegetative pathogens (e.g. Salmonella). Increasing the acidity (reducing the pH) can be achieved in several different ways. The adding of an acid directly (e.g. Vinegar in sauces, pickles and chutneys), adding acidic fruit or juices (e.g. orange juice pH 4; lemon/lime juice pH 2; tomatoes pH 4.2) or adding a bacteria that increases the acidity of its environment as it grows (e.g. the use of a lactobacillus in salamis) Commercially the acidity levels are monitored by using a pH meter and these are inexpensive and can often be afforded by the home curer. Addition of Nitrite (and sometimes Nitrate) When added to foods such as cured meats, nitrite has at least three functions. Firstly, it contributes to the flavour - the nitrite is responsible for imparting the characteristic “bacon” flavour. Secondly, it reacts with myoglobin in the meat which gives the characteristic pink colour of cured meat. Thirdly, it inhibits the growth of food spoilage bacteria, most importantly Clostridium botulinum. The chemistry of nitrite when curing meat is quite complex and the exact mechanism by which it inhibits the growth of C. Botulinum is still a matter of scientific discussion. Nitrite is known to be effective at levels of less than 50mg per Kg of meat. Without laboratory analysis it is not possible to know with certainty how much of the nitrite remains in the meat following the curing process, as within the meat it will undergo a number of different reactions where it can remain free, be bound up byother molecules or cell components, it can be metabolised and broken down. Because of this the use of Nitrite in curing is actually calculated using “ingoing” amounts of Nitrite. Until a few years ago permitted Nitrite levels were ~350 mg/Kg (Ppm) however recently the EU, FSA and USDA have reduced the limits of ingoing nitrite to 150 mg/Kg (Ppm) for uncooked cured meat (and 100 mg/Kg for cooked meat). There are some exceptions for some traditional regional products where higher levels of Nitrite are permitted, however these exceptions limit the amount of residual nitrite in the meat which would have to be established through laboratory testing. As nitrite is gradually broken down in the food it will lose its effectiveness if time for controlling C. Botulinum. For foods that are stored chilled and have a short shelf life this is not a problem however for longer term storage (e.g. Parma/Country style hams and salami style sausages) Potassium Nitrate is also added. The nitrate does not play a direct role in the biological control but over time it is slowly broken down to form Nitrite, replacing the nitrite levels as they are lost. In the USA the use of Nitrate in bacon is no longer permitted as, when heated to high temperatures (e.g. when bacon is fried), the nitrates are converted to nitrosamines which have been linked to cancer in rats. In the UK the situation is less clear however the FSA stipulate that “The use of potassium and sodium nitrate is permitted only in non-heat-treated meat products, to a maximum amount added of 150 mg/kg”. Frying bacon before eating would be considered a heat treatment. Unfortunately, some of the manufacturers of ready-to-use cures (e.g. Supracure) have yet to change their usage instructions to comply with current regulations. When used at the recommended 5%, Supracure will result not only in an ingoing Nitrite level of >300 mg/Kg and will result in Nitrate being included in the bacon cure, but it will also produce a salt level of 5% which most people will find unpalatable. Exclusion of oxygen Preventing oxygen from reaching most bacteria will stop them from growing and increase the shelf life. This can be simply achieved by vacuum packing but can also be achieved by canning. The use of set sugar can also be used to form an oxygen barrier, as in jam. Care needs to be taken when excluding oxygen, as spore forming bacteria (e.g. C. Botulinum) require an oxygen free environment to produce their toxins. It is therefore important that food that is going to be stored this way should also have additional methods of spore control. This could be the use of added nitrite, by reducing the pH through pickling, or by suitable heat treatment. Heat treatment The only way to ensure that your food is effectively free of food spoilage organisms is to heat treat it, although this requires specialist equipment as some bacteria spores (e.g. C. Botulinum) are not killed by boiling water. At 120 C in a pressure cooker/canner (retort) it will take between 10 and 30 minutes kill the C. Botulinum depending on the acidity of the food. Chilling or Freezing The storage life of most foods can be extended by chilling or freezing. Although freezing would appear to be just an extension of chilling they actually work in different ways. The process of chilling food results in the slowing down of the metabolism of food spoilage organisms so that their effect is delayed. Even when chilled to 4 C they will still remain active and will eventually result in the food becoming unsafe to eat. The chilling effect is on both vegetative and spore forming bacteria. When stored at 4 C or below it will take C. Botulinum in excess of 10 days to produce levels of toxin that could begin to become hazardous to vulnerable individuals. The process of freezing works in three ways. Firstly, it continues to reduce the metabolism of the bacteria. Secondly it changes most of the available water to ice which cannot be used by the bacteria. Thirdly it causes ice crystals to form within the bacteria cells which can cause them to rupture – although only some of the bacterial cells will be destroyed. Freezing can help with the removal of water. Fish or meat that has been frozen will undergo some internal cell rupturing (though this usually does not affect the end product) and will result in approximately a 3% loss of water upon thawing. Freezing can also be used to control parasites and flukes in fish that is to be eaten raw. Flukes require to remain frozen at -20 C for 7 days (or -35 C for 15 hours) in order to be killed. Smoking Smoke adds flavour and is both a mild antimicrobial and antioxidant, but since it does not actually penetrate far into meat or fish is insufficient alone for preserving food. When smoking food the smoke is really there for flavouring, however the smoking process can play an important role in the removal of water. The process and effects of curing Examples of different foods and the usual cure methods Type of food Cure/preserving methods Expected shelf life Traditional Smoked Salmon Dehydration Salt Smoke 10 days at 4 C Immersion cured bacon Salt Nitrite Smoke (opt) 14 days at 4 C (unsliced) 1 week when sliced Dry cure bacon Dehydration Salt Nitrite Smoke (opt) 60 days at 4 C (unsliced) 1 week when sliced Hard/Dry Sausage Dehydration Salt Nitrite Nitrate Smoke (opt) Surface mould Whole, 6 weeks in pantry; indefinitely in refrigerator. 3 weeks when cut Salami style sausage Dehydration Salt Nitrite Nitrate Lactobacillus Surface mould Whole, 6 weeks in pantry; indefinitely in refrigerator. 3 weeks when cut Meat or fish Jerky Dehydration Salt Heat Nitrite (opt) Home produced – 1 to 2 months Commercially packaged - 12 months Country (Parma) style ham Dehydration Salt Nitrite Nitrate Whole, uncut ham can be stored safely at room temperature for up to 1 year. The ham is safe after 1 year, but the quality may suffer. Chutney Reducing water Reducing pH Excluding oxygen Unopened, up to 2 years at room temperature 4 weeks once opened Jam Reducing water Sugar Reducing pH Excluding oxygen Unopened, up to 2 years at room temperature Up to 3 months once opened and refrigerated Fermented vegetables Salt Reducing pH (by fermentation) Heat Excluding oxygen 4 months if not boiled, 18 months if boiled.
  7. History. The smoking of food likely dates back to the time of primitive cavemen. As caves or simple huts lacked chimneys, these dwellings would probably have become very smoky. It is supposed that early men would hang meat up to dry and out of the way of pests, thus accidentally becoming aware that meat that was stored in smoky areas acquired a different flavor, and was better preserved than meat that simply dried out. This process was later combined with pre-curing the food in salt or salty brines, resulting in a remarkably effective preservation process that was adapted and developed by numerous cultures around the world. Until the modern era, smoking was of a more "heavy duty" nature as the main aim was to preserve the food. Large quantities of salt were used in the curing process and smoking times were quite long, sometimes involving days of exposure. The advent of modern transportation made it easier to transport food products over long distances and the need for the time and material intensive heavy salting and smoking declined. Smoking became more of a way to flavor than to preserve food. In 1939 a device called the Torry Kiln was invented at the Torry Research Station in Scotland. The kiln allowed for uniform mass-smoking and is considered the prototype for all modern large-scale commercial smokers. Although refinements in technique and advancements in technology have made smoking much easier, the basic steps involved remain essentially the same today as they were hundreds if not thousands of years ago. The reason behind Cold-smoking means exposing the food to smoke at temperatures below 100º F for a relatively long period of time. This flavors the food, but does not cook it—so cold-smoked foods are traditionally preserved via some other means (such as curing) What’s the basic process for smoking foods such as salmon? The first step is to brine it, typically using sugar and spices in addition to salt. Next the food must air dry in order to form the all-important pellicle. The pellicle is a skin or coating of proteins that the smoke molecules can easily stick to; this is especially important with salmon, which develops a distinctly tacky feel when properly brined and dried. The food is then exposed to smoke from a hardwood until it reaches the desired level of dryness and flavor (cold-smoking). Science How does smoking actually preserve food? Along with drying and salting, a number of wood smoke compounds also act as preservatives. Phenol and other phenolic compounds found in wood smoke are antioxidants and help slow the spoilage of animal fats; they also act as anti-microbials, which hinder bacterial growth. Other anti-microbials in wood smoke include acetic acid and other organic acids, which create a low pH – about 2.5 – that also inhibits the growth of bacteria. The end result is both an extended shelf life and a delicious flavor.
  8. To begin the Smokevember month here is an explanation of the roles of the different processes used in curing and preserving. Everyone who cures, smokes or preserves food will use a combination of these methods, often without realising why. When you first begin curing food it can be quite stressful to know whether, what you have just created, is safe for you or your family to eat. However, with even a basic understanding of what you are doing will help you to eat with confidence. The saying "If in doubt chuck it out" is generally good advice, however this can often lead to food that is perfectly safe to eat being thrown away. Fitstly, the more you understand about the processes the less doubt you will have and therefore the less that will be "chucked". Secondly, there are a lot of people who cure and preserve food regularly who are here and can offer you advice. I would therefore recommend that the advice be updated to "If in doubt ASK before you chuck it out" What is curing when applied to food? Curing is a method of preserving food to prevent spoilage. It refers to various preservation and flavouring processes, especially of meat or fish. Spoilage can be prevented (or delayed) by using several processes. Most curing processes involve applying a combination of these to achieve the desired taste, texture and storage time. Sometimes the extended storage time is only measured in days (as in traditional smoked salmon), weeks (as in dry cure bacon) or months/years (as in jerky, salamis and Palma/Country style hams) The different processes that can be used in combination: Reducing available water – including dehydration The growth of bacteria and bacterial spores is significantly affected by the availability of water in their surroundings. Water is also required by the natural enzymes in foods that cause autolysis – the self-destruction of cells by their own enzymes. If the water is removed or made unavailable, the storage life of most foods will be prolonged. Although we could totally remove the water from the food to have the preservative effect, it only really needs it be made unavailable to the spoilage organisms/enzymes. This can be done though several different processes. Removing the water – This is often achieved by warming the food in a relatively dry environment which enables the water in the food to evaporate. The smoking process is a good example of this, where the air that includes the smoke passes across the surface of the food causing the water to evaporate and pass out of the chamber with the smoke. This is why is us usually important to maintain good air flow through your smoker when cold smoking. Changing the state of the water – For bacteria to utilise water it must be in liquid form. One of the effects of placing food into a freezer is that it changes most of the water into ice and therefore make is unusable by bacteria. Freezing, however, does not remove liquid water completely as even when frozen some of the ice will be transitioning from solid to liquid and then back to solid. The lower the temperature in the freezer the less water there will be in liquid form at any point in time. Removing water from the bacteria cells – This is done by increasing the amount of salt and/or sugar around the bacteria, causing the water within their cells to be drawn out by a process called Osmosis. The removal of water from the cells prevents the bacteria from metabolising and growing and often results in their cell walls rupturing and the bacteria being destroyed. Binding the water – Various substances, including sugar, will chemically bind large quantities of water to their molecules and will therefore make it unavailable to the bacteria. This process is one of the important steps when making a BBQ sauce or ketchup that is not going to be eaten immediately. There is still water within the sauce so that it remains pourable, however much of it is bound to the sugars that are also present and which become more concentrated as the volume of the sauce is reduced through simmering. As you can see, you do not need to physically remove the water from the food to have a preservative effect - You just need to make it unavailable for any spoilage organisms to use. Jargon alert: The available water in food is known as Water Activity (aw) and to totally inhibit most spoilage bacteria and moulds an aw of 0.8 or below is required. Many commercial food processers will use an (aw) meter to check that their products are safe for long storage, however these are very expensive and are outside the pockets of most home curers. Even though most home curing processes will not achieve an (aw) of 0.8 or below, there will still be a preservative effect, though more limited, at higher (aw) levels. Increased Salinity – adding salt Salt is usually added in one of three ways – applying directly to the outside (Dry Brining), applying as a liquid solution (immersion brining or injecting), adding salt as an ingredient. There are several ways in which salt will inhibit microbial growth. The most notable is through osmosis, or dehydration (see above). Salt’s other antimicrobial mechanisms include interference with a microbe's enzyme activity and weakening the molecular structure of its DNA. When used as an effective bacterial inhibitor it requires salt solutions of ~10% to make most food spoilage organisms inactive, however salt at this concentration in our food would be unpalatable. Lower salt concentrations will also reduce bacterial growth but to a lesser extent. Many bacteria are very hardy organisms though and as salt concentrations fall the activity of many will again begin increase. The ways of applying salt through the differing curing methods will affect the storage time of the final product. A good example is the difference between Dry cured and Immersion cured bacon. Both methods can be used to produce an end product that contains 2.5% salt, however the resulting shelf life of both methods is very different. Unsliced Dry cure bacon can be safely stored refrigerated for up to 6 weeks whereas the equivalent safe storage life for immersion cured bacon is only 2 weeks. One of the reasons for this is the levels of salt that the bacteria are exposed to during the curing process. With Immersion cure bacon the levels of salt in curing solution will depend on the volume of immersion cure being used and the weight of the meat however it will usually not exceed twice the desired end concentration – therefore will rarely exceed 5% (and will frequently be lower when using larger volumes of cure solution). Although this will inhibit the growth of most bacteria it will not inhibit it completely. When Dry curing bacon you are applying crystalline salt directly onto the surface of the meat – where most of the bacteria will be present. As this salt dissolves in the water from within the meat it results in the surface bacteria being exposed to a saline solution of 100%. As the salt diffuses towards the middle of the meat this concentration will reduce however during normal curing times the surface brine concentration is unlikely to fall below 10% until the salt concentration in the meat is fully equilibrated. Another difference between the two curing methods is that the process of immersion curing will result in an increase in the water content of the meat by about 10%, whereas the process of dry curing will decrease the meat water content. Commercially the levels of salt in brining solution will be measured using a saline meter. These are fairly inexpensive and are often affordable by the home preserver. The electronic salt meters are best as they measure the salt through its ionic properties. Another common saline meter is an optical refractometer. These should ONLY be used for saline solutions that do not also contain sugars, as the presence of sugar will make the resulting "salt" readings highly inaccurate. Increasing sugar Sugar will have a similar osmotic effect on the bacteria cells as salt, causing them to dehydrate, however sugar molecules will also bind water molecules lowering the (aw) and making them unavailable for the bacteria to use. Sugar may also provide an indirect form of preservation by serving to accelerate accumulation of antimicrobial compounds from the growth of certain other organisms. Examples include the conversion of sugar to ethanol in wine by fermentative yeasts or the conversion of sugar to organic acids in sauerkraut by lactic acid bacteria. Increasing acidity (decreasing pH) Increasing the acidity of foods, either through fermentation or the addition of weak acids, has been used as a preservation method since ancient times. In their natural state, most foods such as meat, fish, and vegetables are slightly acidic while most fruits are moderately acidic. Only a few foods such as egg white are alkaline. Generally most food spoilage bacteria thrive within a narrow pH range and as you move away from this range they become increasingly inhibited. The effect differs though between organism. For example, a pH of 4.6 is sufficient to control most spore forming organisms (e.g. C. Botulinum) however a pH of 4.2 is required to control other vegetative pathogens (e.g. Salmonella). Increasing the acidity (reducing the pH) can be achieved in several different ways. The adding of an acid directly (e.g. Vinegar in sauces, pickles and chutneys), adding acidic fruit or juices (e.g. orange juice pH 4; lemon/lime juice pH 2; tomatoes pH 4.2) or adding a bacteria that increases the acidity of its environment as it grows (e.g. the use of a lactobacillus in salamis) Commercially the acidity levels are monitored by using a pH meter and these are inexpensive and can often be afforded by the home curer. Addition of Nitrite (and sometimes Nitrate) When added to foods such as cured meats, nitrite has at least three functions. Firstly, it contributes to the flavour - the nitrite is responsible for imparting the characteristic “bacon” flavour. Secondly, it reacts with myoglobin in the meat which gives the characteristic pink colour of cured meat. Thirdly, it inhibits the growth of food spoilage bacteria, most importantly Clostridium botulinum. The chemistry of nitrite when curing meat is quite complex and the exact mechanism by which it inhibits the growth of C. Botulinum is still a matter of scientific discussion. Nitrite is known to be effective at levels of less than 50mg per Kg of meat. Without laboratory analysis it is not possible to know with certainty how much of the nitrite remains in the meat following the curing process, as within the meat it will undergo a number of different reactions where it can remain free, be bound up byother molecules or cell components, it can be metabolised and broken down. Because of this the use of Nitrite in curing is actually calculated using “ingoing” amounts of Nitrite. Until a few years ago permitted Nitrite levels were ~350 mg/Kg (Ppm) however recently the EU, FSA and USDA have reduced the limits of ingoing nitrite to 150 mg/Kg (Ppm) for uncooked cured meat (and 100 mg/Kg for cooked meat). There are some exceptions for some traditional regional products where higher levels of Nitrite are permitted, however these exceptions limit the amount of residual nitrite in the meat which would have to be established through laboratory testing. As nitrite is gradually broken down in the food it will lose its effectiveness if time for controlling C. Botulinum. For foods that are stored chilled and have a short shelf life this is not a problem however for longer term storage (e.g. Parma/Country style hams and salami style sausages) Potassium Nitrate is also added. The nitrate does not play a direct role in the biological control but over time it is slowly broken down to form Nitrite, replacing the nitrite levels as they are lost. In the USA the use of Nitrate in bacon is no longer permitted as, when heated to high temperatures (e.g. when bacon is fried), the nitrates are converted to nitrosamines which have been linked to cancer in rats. In the UK the situation is less clear however the FSA stipulate that “The use of potassium and sodium nitrate is permitted only in non-heat-treated meat products, to a maximum amount added of 150 mg/kg”. Frying bacon before eating would be considered a heat treatment. Unfortunately, some of the manufacturers of ready-to-use cures (e.g. Supracure) have yet to change their usage instructions to comply with current regulations. When used at the recommended 5%, Supracure will result not only in an ingoing Nitrite level of >300 mg/Kg and will result in Nitrate being included in the bacon cure, but it will also produce a salt level of 5% which most people will find unpalatable. Exclusion of oxygen Preventing oxygen from reaching most bacteria will stop them from growing and increase the shelf life. This can be simply achieved by vacuum packing but can also be achieved by canning. The use of set sugar can also be used to form an oxygen barrier, as in jam. Care needs to be taken when excluding oxygen, as spore forming bacteria (e.g. C. Botulinum) require an oxygen free environment to produce their toxins. It is therefore important that food that is going to be stored this way should also have additional methods of spore control. This could be the use of added nitrite, by reducing the pH through pickling, or by suitable heat treatment. Heat treatment The only way to ensure that your food is effectively free of food spoilage organisms is to heat treat it, although this requires specialist equipment as some bacteria spores (e.g. C. Botulinum) are not killed by boiling water. At 120 C in a pressure cooker/canner (retort) it will take between 10 and 30 minutes kill the C. Botulinum depending on the acidity of the food. Chilling or Freezing The storage life of most foods can be extended by chilling or freezing. Although freezing would appear to be just an extension of chilling they actually work in different ways. The process of chilling food results in the slowing down of the metabolism of food spoilage organisms so that their effect is delayed. Even when chilled to 4 C they will still remain active and will eventually result in the food becoming unsafe to eat. The chilling effect is on both vegetative and spore forming bacteria. When stored at 4 C or below it will take C. Botulinum in excess of 10 days to produce levels of toxin that could begin to become hazardous to vulnerable individuals. The process of freezing works in three ways. Firstly, it continues to reduce the metabolism of the bacteria. Secondly it changes most of the available water to ice which cannot be used by the bacteria. Thirdly it causes ice crystals to form within the bacteria cells which can cause them to rupture – although only some of the bacterial cells will be destroyed. Freezing can help with the removal of water. Fish or meat that has been frozen will undergo some internal cell rupturing (though this usually does not affect the end product) and will result in approximately a 3% loss of water upon thawing. Freezing can also be used to control parasites and flukes in fish that is to be eaten raw. Flukes require to remain frozen at -20 C for 7 days (or -35 C for 15 hours) in order to be killed. Smoking Smoke adds flavour and is both a mild antimicrobial and antioxidant, but since it does not actually penetrate far into meat or fish is insufficient alone for preserving food. When smoking food the smoke is really there for flavouring, however the smoking process can play an important role in the removal of water. The process and effects of curing Examples of different foods and the usual cure methods Type of food Cure/preserving methods Expected shelf life Traditional Smoked Salmon Dehydration Salt Smoke 10 days at 4 C Immersion cured bacon Salt Nitrite Smoke (opt) 14 days at 4 C (unsliced) 1 week when sliced Dry cure bacon Dehydration Salt Nitrite Smoke (opt) 60 days at 4 C (unsliced) 1 week when sliced Hard/Dry Sausage Dehydration Salt Nitrite Nitrate Smoke (opt) Surface mould Whole, 6 weeks in pantry; indefinitely in refrigerator. 3 weeks when cut Salami style sausage Dehydration Salt Nitrite Nitrate Lactobacillus Surface mould Whole, 6 weeks in pantry; indefinitely in refrigerator. 3 weeks when cut Meat or fish Jerky Dehydration Salt Heat Nitrite (opt) Home produced – 1 to 2 months Commercially packaged - 12 months Country (Parma) style ham Dehydration Salt Nitrite Nitrate Whole, uncut ham can be stored safely at room temperature for up to 1 year. The ham is safe after 1 year, but the quality may suffer. Chutney Reducing water Reducing pH Excluding oxygen Unopened, up to 2 years at room temperature 4 weeks once opened Jam Reducing water Sugar Reducing pH Excluding oxygen Unopened, up to 2 years at room temperature Up to 3 months once opened and refrigerated Fermented vegetables Salt Reducing pH (by fermentation) Heat Excluding oxygen 4 months if not boiled, 18 months if boiled.
  9. The Cold Smoking Season is quickly approaching. As I managed to get a Very Large bag of Oak Dust free, thought I might need one of these, Thought it would be bigger than it is? We will be promoting our Cold Smoking event, SMOKEVEMBER on the forum. We will do 30 days of Cold Smoking for November, this will include, Equipment, Techniques and Recipes/Methods. If you have any ideas on what you would like to see or try, let us have your ideas!
  10. Hi All I've done a little cold smoking in my Callow smoker and would like to do some more but would like to give a mailbox mod and vent tubing a try to give more distance between the smoker generator and the food (mostly it'll be cheese) as I've read on several occasions that having more distance allows the smoke to cool and also any tar etc has time to build up on surface to of the tubing rather than on the food which helps to give a cleaner smoke taste and less problems with rising temperatures. Having looked around I've found metal US style mailboxes to be somewhat expensive so I'm looking for alternatives, thus far I've not found quite what I'm looking for and wondered if anyone has any good ideas for alternative items. The smoke generator I'll be using is a 30cm length of stainless perforated tubing on about 1.5 inch diameter. so I need something which will be big enough to house that an allow air space around it. Any ideas will be much appreciated. I'm also thinking about how best to attach the end of my tubing to one of the air intake vents on the Callow without modifying the smoker...
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