The hours spent in late August and September canning another year's worth of relishes, pickles, juices, sauces, jams and preserves are among the most cherished I spend at the stove. It is not only simple, though time consuming, to put up your own supply of food for winter, but also most satisfying.

The literature on canning is so full of warnings and cautions that many would-be canners are scared off before they begin. Put your fears to rest right now.

Botulism, the culprit, occurs primarily in low-acid foods -- rarely in high-acid pickled foods or in high-sugar products such as jams and preserves -- and there really is no reason today for canning low-acid foods. They are far better when preserved by freezing.

Certainly there should be concern about safety -- jars, lids and other essential equipment should be inspected carefully. Also, processing in the water bath should be for the full time designated in the recipes, and afterward the processing seals should be checked.

But that's all that's really necessary for safe canning, and all of the safety measures are clearly explained in the master recipe. Essential Equipment

The most important piece of equipment, which will cost between $25 and $35, is a 33-quart canner kettle equipped with a seven-compartment rack capable of holding quart jars. While any very large pot with a cake rack rigged into the bottom could be used, a jerryrigged setup is not safe and will discourage the first-time canner from ever trying again. A second necessity is a jar-lifter, which is a special set of tongs (about $4) for lifting the jars out of the boiling water bath simply and safely.

Of course, a supply of Mason or Ball jars is necessary, preferably of the wide-mouthed type. The regular narrow-mouthed jars are a little more difficult to handle.

The jars are sealed with dome lids (flat metal discs with a sealing compound on the perimeter of one side) and threaded ring bands. The lids (always use new lids) are secured in place by the threaded bands (which are reusable) before processing, then the bands can be removed after the seal has been checked and found secure. During the processing, the heated food in the jar causes the lids to dome slightly and the air inside is thus driven out. When the jars begin to cool, a vacuum forms inside. This is indicated by the domed lid clicking as it moves from convex to concave in shape.

While there are several other types of jars available, with other types of sealing mechanisms, these seem to be most widely available and the easiest and safest to use. But, whatever type you use, never can in anything but jars specially made for canning.

You'll need a candy or jelly thermometer that has a clip on it so it can be attached to the side of the pot for making preserves, some large wooden spoons (the wood acts as an insulator for long periods of stirring), and a canning funnel (available in kitchenware shops, hardware stores or from some kitchen-equipment catalogues). The First Day

Expect every place you work to be splattered or dripped upon. There is just no way to keep the kitchen immaculate.

Expect the canning to take twice as long as you plan. Canning is not something you can rush.

Expect to get burned, and probably in more than one spot (though not seriously), from hot sputtering preserves or spilled pickle relish. You'll be amazed at how far a pot of hot jam can spatter, so wear long sleeves, jeans or long pants (not shorts or skirts) and socks with an old pair of shoes.

Don't expect to produce a whole cupboard of canned goods on your first day. Start out slowly. Never double a recipe. Recipes that produce about 6-8 pints are just the right size for a normally equipped kitchen. More than that and you probably won't have enough burners for the cooking or enough arms for the stirring. For First-Timers

Start slowly (good advice for veterans, too), invest in the necessary equipment to make your job easy, and remember, there will be other weekends for canning. There is more to can than peaches and raspberries in August; there are apple relishes and pear preserves that can be put up even as late as October or November.

The first day should be dedicated to only two products -- one preserve and one relish in a vinegar-and-sugar solution that requires only the most minimal stirring and preparation. That's two different kinds of canned foods and just enough for a really satisfying day of canning. Unbreakable Rules

1. Never can alone. On the other hand, don't invite half the neighborhood to come by. One friend to help stir and keep the conversation going is all that is necessary or helpful.

2. Plan to spend the whole day canning. Go shopping before 9 a.m. and don't consider stopping until everything has been done and the kitchen is cleaned and back to normal.

3. Don't buy more produce than can be used in a single recipe. Forget having big eyes or wanting to do more than the single recipe suggests. DAMSON PLUM PRESERVES (Master Recipe) (Makes about 14 half-pint jars)

This Master Recipe can be followed as a guide for all canning and preserving, for once you've mastered the basic techniques, there really isn't much difference between a peach jam and a plum preserve -- and except for watching for the jellying point, no real difference between peach jam and corn relish.

6 pounds damson plums

5 pounds sugar

Juice of 7 lemons

2 tablespoons unsalted butter

Inspect the jars; be certain that none is cracked or chipped at the rim. Cracks will cause the jars to break from the heat, chipping on the threading or rims will prevent proper sealing. If any jars are cracked or chipped, discard them.

Examine the lids; these must be new, never used. The lids should be flat. If they are bent from storage they will not seal properly. Also, inspect the sealing compounds, the perimeter on the bottom of the lids. These should be clean in appearance, showing no signs of rust or mold. If dirty, rusted or moldy, rinse under running hot water and wipe gently. If not absolutely clean after this rinsing, discard.

Examine the bands; check to see that the threaded bands are clean and that none has been bent out of shape. These can be washed in hot water with some kitchen detergent, if dirty. If bent, discard because you will not be able to fasten them to the jars properly.

To wash the jars and bands, place them (but not the lids) in the dishwasher and run through a full cycle. This will ensure that the jars and bands are spotless and are sterile. Add a quarter cup of household bleach to the dishwasher just before turning it on to feel absolutely secure that the jars are sterile.

Once the dishwasher has been started, take out all the other equipment needed. Place the lids on a shallow saucepan and add enough hot tap water to just cover. Set outside.

Wash out the canner kettle and place it on the back burner, filled with enough hot water to come to at least 2 inches above the jars when they are lowered to the bottom on the rack. Place an extra empty jar in the rack, lower it into the kettle, and check to be sure there is enough water. Cover the kettle and just leave it on the back burner for now.

Next, place the jar-lifter in a convenient place and wash the funnel with lots of soapy detergent and the hottest tap water you can tolerate. Place the funnel in a bowl and cover with hot tap water to keep it basically sterile until time to use it.

When all the equipment is ready, clean the plums. Take a small handful at a time and hold them under running cold water, rubbing them gently with your hands to ensure that dirt or mold on the surface is cleaned off them. Dirt is a good hiding place for bacteria, so be certain that all the fruits are rinsed thoroughly. Next, either cut the plums with a sharp paring knife and remove the pits, or if the plums are ripe enough, just squeeze them so that the pit pops out. Place the cleaned and pitted plums in a large mixing bowl while the remaining fruits are washed and pitted.

When all of the fruit is ready, transfer it in small batches to a well-washed food processor fitted with the metal blade and process until very finely chopped and fluid. Pour the pure'ed fruit into a large nonreactive pot or kettle (stainless steel or enamel surfaces are nonreactive; do not use aluminum).

Add the lemon juice and sugar and place over high heat. Stir frequently during the first few minutes until the sugar is dissolved, scraping the bottom of the pot each time you stir. Once the sugar is dissolved, clamp the thermometer to the inside of the pot so that it is well inside the liquid but so that the temperature reading around the boiling point is visible.

Add the butter, which will melt and remain on the top of the mixture and which will prevent the mixture from frothing up and over the top of the pot.

Boil the plum mixture rapidly, stirring often, and being certain to scrape the bottom of the pot each time. As the temperature rises to about 215 degrees the bubbling will change in both sound and appearance, a sign that the liquid is near the jellying point. The bubbles will become smaller and will be distributed more evenly throughout the surface of the liquid, no longer gushing.

At that point, skim the scum off the surface of the mixture and stir frequently to prevent scorching.

When the temperature reaches 218 degrees (most preserves jell at 220 degrees, but plums are very high in pectin and their jelly point is a couple of degrees lower than most other fruits) it is ready for the jars. Turn off the heat and remove the pot from the burner. Take the thermometer off the side of the pot.

Filling the jars: Remove seven jars and bands from the dishwasher, as well as the ladle.

Place the saucepan with the lids on a burner set at high and bring it to just under the boiling point. Remove from heat. This is to soften the sealing compound, to ensure complete sealing.

Arrange the jars on the counter and place the kettle close by. Insert the funnel, which can be shaken dry, into one of the jars and ladle it full with the hot preserves. Add preserves to within 1/4-inch of the top of the jar. This is called leaving a quarter of inch "headway." If you let the top edge of the funnel touch the pot, you can ladle the jars full with only a minimal amount of dripping onto the counter. The crease in the bottom of the funnel is at exactly the same point as the top of the jar, so use that as a guide for how high to fill the jars.

Wrap a clean kitchen towel or paper towel around your index finger and dip into hot water. Rub the wet towel around the top edge of each jar to ensure that the surface is clean and free of any dripped preserves.

Carefully lift the lids out of the scalding water and place them, sealing compound side down, on top of the jars. Screw a band onto the jar, tightening it firmly in place. When the band is tight, the lid will have just enough give to let the air escape during the processing. Cover the remaining jars in the same way. Do only seven.

To process, carefully lift the rack in the canner kettle up and hang it on the sides of the kettle. Place the first jar in the center well of the rack so it will remain balanced, then add the remaining jars.

Lower the rack to the bottom of the pot then release the handles. Cover and process the preserves for exactly 10 minutes from the time the water returns to a full rolling boil.

While the first batch of jars is processing, bring the remaining preserves back to a boil and fill the next set of seven jars in the same way you did the first batch.

After the full 10 minutes of processing, lift the handles off the rack out of the water and secure them on the side of the kettle. Using the jar-lifter, remove the preserves, one jar at a time, from the rack and place them on a large cake rack or wood surface, (or formica) leaving plenty of space between them to cool.

Do not place the jars in a draft or on a cold surface, which could cause the jars to crack. Do not tighten the bands after the jars are removed from the processing bath as this will cause the seals to break.

As you lift the jars out of the water, some of the lids may make a clicking sound, indicating that the seal is complete. Some will not pop until the preserves are considerably cooler.

Bring the water back to a boil, then process the remaining preserves in the same way.

If there are enough preserves left after the second batch to process another jar or two, by all means fill and process them. If only a portion of a jar is left over, simply store it in the refrigerator and use first. Whatever amount is left over is called the taster, for everyone will want to taste the preserves.

Once the jars have cooled completely, check the seals. Do this by tapping on the top of the lids. If the lids make no sound, or if there is a click and the lids stay down, the seals are complete. If the lid pops up and and down when you tap on it, the seal is not complete.

Any jar that has not sealed completely, for whatever the reason, can be emptied, the preserves brought back to a boil, and then poured into a new sterile jar and capped and processed again. Or, if you prefer, just place it in the refrigerator and use it within one month.

Label the jars as to contents and date them.

Store the jars in a dark cool place. Ideally the temperature should be about 60 degrees or less. Light will cause the preserves to discolor, as can too warm a temperature. But even under less than ideal storage conditions (I usually store mine in cardboard boxes in the bottom of a closet) the preserves will last 2 or 3 years. Label the sides of the jars if storing on open shelving, write the label directly onto the lids if storing in boxes.

Variations:

Peach preserves: Use 6 pounds of peaches, washed and pitted, with 4 pounds of sugar and cook with 2 or 3 sticks of cinnamon, each about 2 1/2 inches long.

Gingered peach preserves: Just before ladling the preserves into sterile jars, mix 12 nuggets of finely chopped preserved ginger into the preserves. DAVID'S DILLED GREEN BEANS (Makes about 6 pints)

Dilled green beans are made just like pickles, but the change from cucumbers to green beans makes them a welcome and wonderful surprise. Serve anytime you'd normally serve pickles.

6 bushy stems of fresh dill, thoroughly rinsed under running cold water

12 plump, large garlic cloves

2 tablespoons each dill seeds, mustard seeds, celery seeds, and dried oregano

3 pounds tender young green beans, washed and snapped (when picking the beans at the market, try to have them all the same diameter so they will all cook to the same degree of doneness during the processing)

3 cups water

3 cups cider vinegar

6 tablespoons pickling salt

Into each of 6 sterile jars (see master recipe), place the top 3 to 4 inches of a single stem of fresh dill, 2 garlic cloves, and a scant 1/2 teaspoon each of dill seeds, mustard seeds, celery seeds and dried oregano. Line the beans up next to each other in small bunches, then pack as tightly as you can into the jars with the beans standing upright.

Bring the water, vinegar and salt to a full boil and ladle over the beans, leaving 1/4-inch headway. Wrap the jars on the counter to remove any bubbles, then check the headspace. Cover, seal and process as directed in the master recipe -- process very young beans for 10 minutes, medium-sized, less tender beans for 16 minutes. MYRA BURNETT'S ENGLISH MINT CHUTNEY SAUCE (Makes about 5 pints)

This simple-to-prepare, chunky mint-flavored chutney was a traditional accompaniment for lamb for the Burnett family, but has now become a Burnett summer favorite with all kinds of game and poultry as well. Try some with cold poached salmon for a very special treat.

3 cups 5% acid cider vinegar

2 cups sugar 2 teaspoons dry mustard

2 pounds ripe (preferably homegrown) tomatoes, cored and coarsely chopped

2 pounds tart apples, stems removed, cored and cut in 1/4-inch dices

3 large sweet green bell peppers, cored, seeded and coarsely chopped

6 small onions

1 cup finely chopped fresh mint

1 1/2 cups golden raisins

In a large nonaluminum pot, bring the vinegar, sugar and mustard to a boil. Add the tomatoes, apples, peppers, onion, mint and raisins. Stir well, then cover and bring back to a boil.

Ladle into sterile jars (see master recipe), leaving 1/4-inch headway. Wrap the jars on the counter to remove any bubbles, then check the headspace. Cover, seal, and process in a water bath for 10 minutes as directed in the master recipe. AUNT NELLIE CUNNINGHAM'S SWEET AND SOUR CORN RELISH (Makes about 7 pints)

Most great canning recipes are old family recipes (this one was given to me by a friend whose family has lived in the D.C. area for four generations). This is a great corn relish, as classic as succotash and apple cider to American cooking. It can be made with yellow corn, of course, but Mrs. Cunningham says it is best with tender sweet white corn.

20 ears of sweet corn (silver queen, if possible), about 1/4 bushel

2 cups each coarsely chopped green sweet peppers, red peppers, onion and celery

2 cups sugar

1 1/2 tablespoons each pickling salt, mustard seed, celery seed

2 teaspoons dill seed

3 3/4 cups 5% acid cider vinegar

Shuck the corn and carefully remove all the silk adhering to the ears. Rinse under running cold water, then, with a paring knife or a special device for removing the niblets from an ear of corn, cut the niblets off the stalks. Combine with the peppers, onion and celery in a large bowl and mix well.

Combine the remaining ingredients in a large nonreactive pot and bring to a rapid boil. Add the vegetable mixture and bring back to a boil.

Ladle into sterile jars, leaving 1/4-inch headway. Wrap the jars on a counter to remove any air bubbles, then check the headway. Cover, seal and process for 10 minutes as directed in the master recipe.