ACETIC ACID: The primary colorless, naturally occurring acid that makes vinegar sour, most commonly at a 5% solution content.
ACID: A naturally occurring chemical compound that produces hydrogen ions when dissolved in water and usually reacts with a base to form a salt. Acids have the property of neutralizing alkali.
ALTITUDE: A vertical physical measure of a location based on vertical height above sea level.
ANTIOXIDANT: A naturally occurring substance found in ascorbic acid (also known as Vitamin C) and citric acids, found in Lemon and Lime juice, which controls the browning of fruits and vegetables and is attributed to the neutralization of harmful free radicals, which can build up in your body, leading to cell damage and/or disease.
ARTIFICIAL SWEETENER: Any synthetic sweetener with little to no nutritional value used as a substitute for natural cane sugar.
ASCORBIC ACID: A naturally occurring acid, also known as Vitamin C, used as an anti-browning agent for pre-treating certain fruits before processing. It is commercially available as a powder form used to set jams and jellies.
BACTERIA: A large variety of widely distributed vegetable micro-organisms which convert dead organic matter into soluble food materials for plants, many of which are pathogenic, causing illness and diseases. Low acid food products require a longer, hotter processing time to kill these bacteria. These food products must be brought to 240 degrees F (116 degrees C) for an extended period of time in a pressure canner.
BLANCH: By dipping fruits and vegetables in boiling water briefly (usually 1-3 minutes, depending on the food variety) to kill enzymes and to loosen the skins of tomatoes, peaches or nectarines to make them easier to peel. Rapid cooling of fruits and vegetables immediately after boiling will be required and is achieved by dumping the produce in ice water immediately after removing from the boiling water.
BOIL: Heating water to a temperature of 212 degrees F (116 degrees c) at sea level produces rapid rising air bubbles which cause a rolling effect on the surface of the water. Most recipes refer to two levels of boiling described by the action of the water. 1.) Gentle Boil: Also referred to as a simmer, a gentle boil is produced when the water temperature is a few degrees below boiling point (between 180 to 210 degrees F)and the surface of the water is only slightly disturbed. 2.) Full, Rolling Boil: Also referred to as a rapid boil, a full, rolling boil cannot be stirred down and the surface of the water is completely disturbed when the water reaches 220 degrees F. This is the boil required for successfully processing in a boiling water bath.
BOILING WATER CANNER: Any large stainless steel cooking pot with a lid big enough to contain a jar rack, filled jars and at least one inch of water, adding another 1 1/2 - 2" for the water height when boiling. This canning equipment is used to process high acid food products that can be safely processed at 220 degrees F.
BOTULISM: A potentially fatal toxin secreted by the bacterium Clostridium botulinum sometimes present in food which has not been properly canned or preserved. This type of bacteria does not thrive in the presence of air or high acid foods, but, rather, prefers air tight environments with low acidity. Processing low acid foods will require hotter temperatures and long processing times to kill the botulism spores.
BRINE: A saline (salt) solution used to pickle or preserve food products, sometimes combined with sugars and spices in specific recipes to add to the flavor of brined foods.
BUBBLE REMOVER: A non-metallic device used to release air bubble that become trapped inside filled jars of canned fruits and vegetables which should be removed before the canning jar lids are placed on the jar. The removal of all air bubbles is critical in achieving the proper head space required for each specific recipe, usually filling the food product to between 1/2" and 1/4" from the top rim of the jar.
CALCIUM CHLORIDE: A commercial available naturally occurring salt found in mineral deposits used as a crisping agent in some pickle recipes.
CANDY THERMOMETER: A thermometer used in canning to monitor the temperature of fruit being processed for making soft jam and jelly spreads without the use of commercial pectin. Proper gel stage is reached at approximately 220 degrees F, assuring the spread will gel properly.
CANNING LIQUID: Any combination of liquids, such as vinegar, water, juice or syrup, used to cover the produce while cooking and filled into the jars with the produce to help keep the food product under the surface and from darkening. The liquid in the jars helps the heat from the boiling water in the canner to penetrate throughout the filled jars, assuring the proper processing temperature is acquired within the jar.
CHEESECLOTH: A loosely woven fabric used in the processing of jellies which is dampened and placed in several layers into a colander placed over a bowl to collect the drained juices of the fruit to be used to make the jelly. Cheesecloth is also frequently used to tie up whole cloves, pepper corns, bay leaves, and other spices in a removal pouch that aids in the removal of the spices from the canning liquid.
CITRIC ACID: A white, odorless acid with a sour taste found in many plant cells, especially in the juices of oranges, lemons and limes, used to pre-treat produce to keep it from oxidizing when exposed to air. It is also used in commercial pectin products used to make jams and jellies to aid in gel formation by increasing the acidity.
CLEARJEL: A commercially produced liquid food starch used in home cooking and processing of jelly and jam products.
COLD or RAW PACKING: A method of packing raw fruits or vegetables into hot, sterilized jars, along with specified spices required in the recipe. The hot canning liquid is poured over the food product into the jars to within the proper head space before the jars are sealed in preparation for processing at the proper time and temperature required.
CONDIMENT: A sauce made of vegetables and/or fruits which is used to enhance the flavor of certain entrees. Some examples of such sauces include catsup, salsas or dessert fruit spreads.
COOL PLACE: A location used in cold storage of some produce and all canned goods which is out of direct sunlight and has an optimum temperature of between 50-70 degrees F. (10-21 degrees C)
DEXTROSE: A crystalline sugar less sweet than pure cane sugar widely used in commercial food products. It is a main ingredient in fruit pectin products sold to help gel jam and jelly products.
E. COLI: A potentially deadly bacteria normally found in the intestines of humans and animals, but, when the toxins are consumed in quantities, can produce high fever, chills, diarrhea and headaches.
ENZYME: A complex protein produced in living cells that is able to cause changes in other substances within the body without being changed itself, causing the start of decomposition, changing the color, flavor and texture of produce and food products. The effects of enzymes on food can be neutralized by processing all canning projects at the proper temperature and for the recommended times.
FERMENTATION: A process that foods undergo in which a gradual chemical decomposition, giving off bubbles off gas and causes a scum to form on the surface. Although this process helps in the fermentation of wines and some pickles, it is not a good condition for food products which have been preserved at home. If any jar of home canned produce shows signs of fermentation, which include rising air bubbles, the sealed lid projecting outward, and/or a scum layer over the surface of the canned product, discard immediately!
FOOD MILL: Any number of sieve devices designed to strain soft foods into a sauce of fine texture, such as in applesauce, fruit butters and purees. These sieves are time savers in that the fruit does not have to be peeled or cored, taking advantage of the additional nutritional value of the peels of the fruit.
FRESH PACK: This method of canning pickles involves soaking the cucumber slices in layers with salt in water for a period of time ranging from 2 hours to overnight, depending on the recipe. The slices are then rinsed, drained and cooked in a mixture of vinegar and spices and processed in a boiling water canner.
FRUIT BUTTERS: Fruit pulp that is thickened by slow cooking over low heat with honey or sugar to produce a soft spread suitable to be processed in a boiling water canner.
FRUIT PICKLES: Fruits such as peaches, nectarines, and watermelon rinds which are boiled in a spicy sweet syrup. These fruits are usually peeled and processed whole or in halves, which can be either cold packed or hot packed, depending on the specific recipe.
FUNNEL: A device especially designed with a wide upper bowl that tapers down to a round, short opening which fits onto the top of the canning jar to aid in the filling of the jars. This funnel is very helpful in avoiding spillage of the hot ingredients, reducing waste and keeping the rim of the jar clean when filling.
GEL STAGE: When processing soft spreads and jellies without commercial pectin, the temperature of the fruit and sugar mixture needs to reach 220 degrees F to form a soft, thick, semi-congealed spread.
HEAD SPACE: In order to form an strong airtight seal and allow for proper food expansion during the heating process, the proper head space should be maintained. This measurement is the distance between the surface of the canned food product, once filled into the sterilized hot jars, from the top of the jar lid. Most recipes are specific about the amount of head space, which usually ranges from 1/2" to 1/4". By keeping the head space consistent with each batch, you assure that all of the jars are sealed at the same time.
HIGH-ACID FOOD: Almost all fruit and tomato products are naturally high in acids which aid in the destruction of certain bacterias which can spoil food. In the processing of lower acid foods, which have a pH lower than 4.6, lemon juice or vinegar is usually added, such as in the case of pickles, to raise the acid levels to allow for processing in a boiling water canner.
HOME CANNING: Processing food products for the purpose of preserving them for later use by means of a boiling water bath or pressure cooker is called home canning. Many vegetables and fruits can be canned at home to extend the availability of garden-fresh produce throughout the year. Specially designed canning jars with special lids are available, which can be reused and are totally renewable.
HOT-PACK METHOD: Some recipes call for boiling the food product before it is added to the hot, sterilized jars, called hot pack method. Boiling the food product helps reduce the amount of air and reduces the chances of the ingredients rising to the surface of the liquid instead of staying submerged and dispersed to ensure freshness and flavor. For these reasons, it is the preferred method for home canning, unless otherwise noted in specific recipes.
JAM: Fruits that are mashed or chopped and heated with other ingredients, such as sugar, lemon juice and/or pectin and heated to a boiling point before being hot packed into hot sterilized jars are called jams. All of the fruit is used to make a soft spread, which is what distinguishes them from jellies, which are clear. In order to make jams without commercial pectin, the food product should be boiled for a longer period of time to reduce some of the water and thicken the fruit. Stirring constantly from the time the mixture starts to boil is crucial to prevent scorching!
JAR: There are several commercial canning jar suppliers, both locally and on the internet, that offer a variety of clear glass containers, or jars, designed to withstand repeated processing and the high temperatures necessary for home canning projects. They all have specially designed lids and screw rings designed to insure a proper seal specific to either the "wide mouth" or "regular mouth" jars. These jars are available in a large variety of sizes, ranging from 2 ounces to 1 quart and some have straight sides while others have shoulders. The straight sides are suitable for jellies and jams, but, lack the shoulders to help keep the foods submerged in the canning liquid. Please resist the urge to use recycled commercial product jars from the grocery store. These jars are designed to withstand only one high heat processing and the mouths are not standard and will not fit the sealing lids needed for a proper seal. Today, most mayonnaise jars are plastic and should never be used for home canning projects.
JELLY: A soft, spreadable gel made from the juices of fruits (and some peppers and mint) is called jelly. The mashed or chopped food product is boiled and strained to separate the juice, which is then reboiled, adding the sugar, spices, lemon juice and pectin and sealed into hot, sterilized jars.
JELLY BAG: Commercially made muslin bags are available for use in making jellies. Some of these are easier than others to fill with the hot food pulp to be strained. An easier, more accessible solution is to line an enamel or stainless steel colander with either muslin or a few layers of cheesecloth and place it over a large bowl to collect the juices. Jelly bags need to be hung over a bowl to drain There are specially designed jelly strainers available which include a stainless steel frame on which you stretch the jelly bag, which is filled and left to drain over a bowl. If you are particular regarding the clarity of the jelly, then please resist the urge to squeeze the jelly bags, as this will release small particles of the fruit into the juice. This will not effect the taste of the jelly, only the clarity.
LITER (L): A metric form of measurement by volume. A liter is equal to 1.0567 U.S. Quart liquid measure and 0.908 U.S. Quart dry measure.
LEMON JUICE: Many recipes for home canning require lemon juice to boost the acidity and aid in gelling of some food products to be home canned. Fresh squeezed lemon juice is acceptable unless bottled lemon juice is specifically called for in the recipe. The reason for this is due to the fluctuating levels of acidity in various lemon varieties. Commercially bottled lemon juice must meet standards for acidity which guarantees that the acidity level will be consistent.
LID: Home canning jars are designed to be sealed with a two-piece top. The flat, round disc is called the lid. The other part of the closure is the screw band that tightens the lid down onto the rim of the jar. The interior side of the disc has a strip of sealant which runs around the outer circumference and is designed to form a tight seal along the rim of the jar during the heat processing time.
LOW-ACID FOOD: Almost all vegetables, meats, poultry and seafood contain very little natural acids and have a pH of over 4.6, which is considered to be low in acidic scales. Because harmful bacteria thrive at these levels, it becomes necessary to process these food products in a pressure cooker to raise the heat of the food to 240 degrees F (116 degrees C at sea level) to kill off the microorganisms.
MARMALADE: A soft, spreadable gel made primarily of citrus fruits using the zest and peel to give it a distinctive, slightly bitter taste, is called marmalade.
MEASURING CUPS: Ingredient measurements are calculated in most recipes according to the universal standard for weight and volume. Liquid measures are usually glass or plastic and are specifically calibrated to allow the measure to be poured into the glass measuring cup with the level of the liquid visible along the marked sides and a space provided between the top most measure and the lip of the container. There is usually a pour spout and a handle for easy pouring. Dry measures are calibrated by spooning the dry ingredient into the cup until it is filled above the level of the cup and then wiped with a knife to flatten the ingredients to the top of the rim of the cup. This method assures a full measure. Most are marked for both Imperial or Metric measures.
MICROORGANISM: A living plant or animal so small that it can only be seen in a microscope. There are many such organisms that can spoil home canning projects, which is why the proper procedures and heat times are crucial to assure that these microorganisms are killed.
MILLILITER (mL): A metric measure of volume which equals 0.0338 of a fluid ounce Imperial or 1/1000th of a liter.
MOLD: Microscopic woolly or furry fungous growth, often greenish-blue or whitish in color, that appears on the surface of food and other animal or vegetable substances when they are left too long in a warm, moist place or when they are decaying, is called mold. Mycotoxins are often produced which are poisonous to humans, and are very happy in low-acid foods, but, are easily destroyed at temperatures above 140 degrees f.
OXIDATION: When working with fruits such as apples and peaches, a discoloration known as oxidation occurs. This happens when the surfaces of the fruit are exposed to oxygen, which breaks down the texture of the fruit and causes the surfaces to turn brownish.
PARAFFIN WAX: When our grandmothers canned jams and jellies, many times they would seal the tops of the jars with melted paraffin wax. This practice has been deemed unsafe and is never recommended for home canning as no heat bath is utilized to kill the existing bacterias and molds.
PECTIN: Most fruits and some vegetables have a naturally occurring carbohydrate that helps with the cell structure of these fruits. As the food products ripen, the pectin levels are reduced, allowing them to loose their shape and become softer. Commercial pectin comes in either a powdered or liquid form and is used primarily when canning jams and jellies. I prefer the powdered form because it is an all natural product as opposed to the liquid form which contains sodium benzoate as a preservative. Always read the labels, especially if natural, chemical free home canning is your goal.
pH (potential of hydrogen): A symbol used in science (followed by a number) to express acidity or alkalinity in testing soils, foods and other substances, which represents the reciprocal of hydrogen-ion concentration in a given solution. The scale of number readings range from 0 to 14, with the number pH7 representing a neutral reading. pH 0 through pH 6 are considered increasingly acidic and pH 8 through ph 14 considered increasingly alkaline (or low-acid). Low-acid foods should be processed in a pressure cooker to hotter temperatures of 240 degrees F at sea level, while high-acid foods can be processed in a boiling water bath which reaches 212 degrees F.
PICKLING: Preserving cucumbers and other low-acid vegetables using a solution of vinegar to increase the acidity, mixed with spices and other ingredients is called pickling. Pickled food products are processed in a boiling water bath.
PRESERVES: Fruits which are processed whole, using sugar to preserve them, allowing the fruits to keep their shape and color are called preserves. Most preserves are processed with a sugar solution which varies in texture from thin syrupy gels to a consistency similar to honey. True preserves do not hold their shape when the jar is tilted or spooned out.
PRESERVE: Preparing food products in a method which keeps them from spoiling for extended lengths of time is called preserving foods. Many different ways are available to the home food preserver, including drying, canning, freezing, salt and/or smoke curing and refrigeration.
PESSURE COOKER or CANNER: A large, heavy pot with a locking lid and a pressure gauge built in to help regulate the pressure, is called a pressure canner. These canners are used to process low-acid foods with the help of pressure and steam to increase the temperature to 240 degrees F (at sea level)to kill off harmful microorganisms found naturally in foods.
PROCESSING, HEAT PROCESSING, or HOT PROCESSING: Using heat from a boiling water bath or pressure cooker to kill off the harmful organisms, molds and bacterias in filled sterilized jars is called Heat Processing. This processing is essential for successful home canning projects to help force out excessive air and gases to form a tight vacuum seal to keep the food products from further contamination or spoilage. Avoid any home canning recipes that do not call for heat processing.
PROCESSING TIME: Home canning recipes will specify the duration of the time the jars are processed in order to assure that the coldest spot in the filled, sealed jars is heated to the proper temperature to kill harmful microorganisms. The time will depend on the density of the canned foods and will vary from one recipe to another. The processing time begins when the water in the boiling water bath is boiling. In the case of pressure cookers, the timing starts when the gauge reaches the desired temperature of 240 degrees F.
RAW PACK: Occasionally a recipe will call for you to put the food product raw in the hot, sterilized jars. When this is called for, the hot vinegars, spices and sugars are poured into the jars over the raw vegetables. The jars are sealed and placed into a hot boiling water canner for processing. This process is called raw packed processing.
REFRIGERATION: Placing fruits and vegetables in cold storage for brief periods of time in your refrigerator to slow the growth of microorganisms and deterioration of the food product. This is only a temporary solution, which will vary, depending on the food in question. Potatoes, of course will last longer in cooler storage than strawberries, for example. Keep in mind that only the freshest, most blemish free foods should be used in home canning and preserving projects, so keeping foods for even short periods of time refrigerated will only slow down the oxidation process briefly.
RELISH: Chopped fruits and/or vegetables that are cooked in a seasoned vinegar solution are called relishes.
REPROCESSING: Occasionally home canning projects do not always turn out as planned, after all of that work! In most instances you will know within a couple of hours if the jars you processed were able to create an airtight seal. However, if after 10 or 22 hours you notice that some of the jars did not seal, all is not entirely lost! The solution is to reprocess the batch that did not seal. This will involve emptying the food product back into a large pan, heating it as the original recipe instructed and placing the newly processed food into new, hot, sterilized jars, using NEW lids. Always check for chips along the rim of the jar and imperfections along the lid sealant strip. The food can then be processed again for the specified amount of boiling time.
SALT: You may have noticed that there are several kinds of salt available on the market, ranging from evaporated sea water salt, table salt, Kosher salt and pickling/canning salt. Each have distinct properties making some suitable for home canning projects, while others are not.
The most commonly available salt is called TABLE SALT. This commercial product is usually mined salt that has anti-caking ingredients and iodine added. This salt is NOT acceptable for home canning projects as the iodine can cause discoloration of the food after processing.
KOSHER SALT is a coarse-grained salt free of all additives. This salt is suitable for home canning projects, but, because the density of the salt varies, proper saline content for your home canning projects may be compromised.
SEA SALT is derived from evaporating sea water and collecting the salt left behind. It comes in a variety of grit from fine to very coarse and even in colors ranging from green to pink and amber. Due to the natural minerals that will also be left on the salt particles as the sea water evaporates, it is not suitable for home canning, as discoloration of the food might occur.
The best choice for successful home canning projects is PICKLING and/or CANNING SALT. This salt is finely grained to dissolve quickly and is free from anti-caking ingredients, which can cloud the liquids, and iodine, which can discolor the food product. Because most home canning recipes call for CANNING SALT, you will be assured that the saline level required to properly process the food will be maintained.
SALT CURING: One of the first methods of preserving foods available to our ancestors was salt curing. This methods usually consists of soaking the beef, pork or fish in a salt-water solution to absorb the salt and/or rubbing the surfaces of the food with large amounts of salt, coating completely all outer surfaces and allow the meat to cure for long periods of time.
SAUCEPAN: In home canning, a large stainless steel or enamel saucepan with a thick flat bottom and straight sides is essential. The saucepan should be at least 8 to 10 U.S. Quarts and should be easy to handle when hot. When making jams, jellies, and pickles you might be tempted to use a smaller pan, but, trust me, when the jam reaches a "rolling boil that can not be stirred down" for the required amount of minutes, the volume of the fruit and sugar mixture increases dramatically!
SCREW BAND: Modern jar closures come with two components. The flat metal disc is the lid and the threaded metal band that holds the disc in place during processing is called the screw band. When applying the screw bands to the jars with the lid in place, be careful not to tighten the bands too tightly...tighten only as tight as you can get the band using your fingertips, no more.
SEALANT or SEALING COMPOUND: Located on the outer perimeter of the interior surface of the metal disc lid of the two part closure recommended for modern home canning products, is a red strip designed specifically to form an air-tight seal during the heating process of filled jars. As the jars and food products heat up, tiny bubbles of air are forced out of the top, which is why it is important to always process for the recommended period of time. As the jars cool, a vacuum seal is created, sealing your food products tightly.
SKIMMER: During the processing of certain home canning project, such as pickles, it will be necessary to put the cooked cucumbers into the hot, sterilized jars. This will require dipping the hot cucumbers out of the boiling liquid. A long-handled, slotted spoon or other utensil with holes large enough to allow the liquid to drain through, but small enough to keep the food from slipping through is known as a skimmer. Skimmers are also useful when cooking jams and jellies to separate the foam that forms during rapid boiling from the finished product before filling into the jars.
SMOKE CURING: One of the first methods used by our ancestors to preserve meat and fish was to slowly cook the fresh meat in confined areas, suspended over a continuous, slow, smokey fire for long periods of time. The smoke imparts a distinctive flavor throughout the meat, which can vary, depending on what wood is used. Popular choices have always been hickory, mesquite, apple and maple wood. I must note that there has been considerable debate lately regarding the safety of eating such smoke-cured meats, siting studies regarding the consumption of the compounds known to be found in the smoke.
SPICE BAG: Some recipes require that the spices used be put into a muslin or cheesecloth bag in order to impart the flavors of the spices into the food product without having to filter them out of the finished canned project. The easiest way to do this is to cut a few layers of cheesecloth into a 4" square, place the required spices in the center and tie the ends together to for a spice "tea bag" with twine. Commercially made spice bags are available, usually where home canning supplies are sold, but cheesecloth is more readily available in my area and is useful in a wide variety of ways.
SPOILAGE: If at any time you reach to open a jar of home canned goods and notice that the jar has a broken seal, there is mold floating on the surface, the liquids seem cloudy or bubbly or are spurting or seeping from the jar, or yeast growth, fermentation, slime or disagreeable odors are present in the jar, DO NOT CONSUME! These are signs of spoilage, which can cause severe gastric intestinal poisoning and should be avoided at all costs. If there is ANY doubt...throw it out! Dispose of the contents in a manner that will assure that no other person or animal will be able to consume it, such as in a tightly-covered trash container.
STERILIZATION: In home canning, killing of harmful microorganisms through heat is called sterilization. All jars to be used should be boiled in hot water, the lids soaked in hot water and the filled jars processed in either a boiling water bath or pressure cooker/canner. This is extremely important in order to lower the risks of contamination or spoilage.
STORAGE: A relatively cool, dark place which is dry and convenient is an excellent place to store home canned goods until you are ready to use them. A cupboard in the kitchen or pantry is perfect.
SUGAR CURED: Large quantities of sugar, like salt, have the ability to slow down microorganism growth. This technique is used for hams and other meats. Citrus slices are commonly coated in sugar and dehydrated to make a beautiful snack! Confectioners often dust flower pedals with sugar to make beautiful accents on cakes and other treats!
SYRUP, or CANNING SYRUP: A mixture of water and sugar in different concentrations (light, medium or heavy) are often added to canned fruits to add liquid and help preserve their texture and color. The syrup concentration is usually recipe specific, and will be discussed for each recipe.
THERMAL SHOCK BREAKAGE: Glass jars, when exposed to extremes of temperatures, are weakened by the stress and are likely to break along the bottom of the jar. Checking your jars for chips and cracks before starting the canning process will help prevent this shock and keeping the jars hot while cooking the canning ingredients will also lessen the chance of sudden breakage due to extreme temperature changes.
TWO PIECE CLOSURE: Specially designed jar closures consisting of a metal disc lid and a round, threaded screw band are referred to as two piece closures. The top is a metal disc coated on the inner surface to protect foods from metal exposure and a sealing compound that is designed to form a thermal, air-tight seal when the filled jars are heat processed. The screw band is designed to hold the lid in place during the canning process. After the required processing time, the jars are set out to cool and seal. After 24 hours or so you should know if the jars were properly sealed. At this point it is recommended to remove the screw bands to make sure the seal is tight and to clean the surfaces under the screw band to remove any food that might have accumulated during the filling or processing of the jars. I prefer to replace the screw bands after I have checked the seal and wiped the threads clean to help protect the lid in the event that the jars are knocked together or handled roughly. This is particularly important for straight sided jars whose tops are more vulnerable to nicks.
VACUUM SEAL: During the heating process in either a boiling water bath or pressure cooker/canner the food products expand slightly, forcing small amounts of air out of the jars from under the lid. As the home canning jars cool, the food products cool and retreat back to the original fill line, forming a vacuum in the head space, drawing the lid down. This is the reason that the proper head space should always be followed as per the recipe being used. An audible pop will signal that the lid has sealed. The specially designed sealing compound found on the inner perimeter of the lid forms around the top of the jar keeping out any air that might seep back in, which could recontaminate the food products. For this reason it is NOT recommended that the lids ever be reused, as the sealing strip could be compromised.
VENTING: The process of releasing heated air from the filled jars being processed to form an air tight vacuum seal is referred to as venting. This term is also used to refer to the releasing of air from the pressure cooker/canner to keep the desired pressure required in the recipe.
VINEGAR: The result of a chemical change, known as fermentation, to form a weak alcohol using the juice of almost any fruit, berry, grain, or wine to produce an acidic liquid known as vinegar. The color and flavor depends upon which juice is used.
CIDER VINEGAR: An acidic liquid made from cider, the partially, or fully fermented juice of apples, is called cider vinegar. It has a milder acidic taste than white, distilled vinegar, imparting a slight apple taste and is a golden amber in color. It is perfectly suited for home canning projects, as long as the acidic content is 5%. Keep in mind that the color of the vinegar will impart a golden hue to the home canning food, particularly in white or lightly colored fruits or vegetables.
DISTILLED, WHITE VINEGAR: A colorless, pungent acidic liquid made from the distillation of grain alcohol is called white or clear vinegar. In home canning, this vinegar is perfectly suitable to use, because the taste of the vinegar does not compete with the other ingredients, the way malt, wine or cider vinegars can. The acidity level should be 5%. Because the vinegar is clear, the color of the food products stay light.
WINE VINEGAR: An acidic liquid derived from wine is called wine vinegar. They can be made from white or red wine and the color is either red or a very light amber and taste imparts a mild wine flavor.