Test each rubber before you use it by pressing it firmly between the thumbs and forefingers, stretching it very slightly.  If it seems soft and spongy discard it.  All rubbers fit for canning should be firm, elastic, and should endure a stretching pull without breaking.  A good rubber ring will return promptly to place without changing the inside diameter.

A great many women are laboring under the wrong impression that color affects the quality of a ring.  Some women insist on red, and others on white.  Color is given to rings by adding coloring matter during the manufacturing process.  The color of the ring is no index to its usefulness in home canning.

Use only fresh, sound strawberries or other berries.  There is a little knack about preparing the strawberries that few housewives know.  Hull the berries by twisting the berries off the hull, instead of pulling the hull from the berry as most women do.  You will have a better-looking berry if you will be careful about this.  Place the berries in a strainer and pour cold water over them to cleanse them.

HOW TO ADJUST THE COVERS

Never allow the berries or any fruit to stand in water, as the flavor and color are destroyed by water-soaking.  Pack in glass jars, pressing the berries down tightly, but without crushing them.  Put the rubber on the jar if you are using a jar requiring a rubber.  Pour hot sirup over the berries.  Put the top of the jar in place, but only partially tighten it.

If using the screw-top jars, such as the Mason, screw down with the thumb and little finger, not using force but stopping when the cover catches.

If using vacuum-seal jars put the cover on and the spring in place.  The spring will give enough to allow the steam to escape.

In using glass-top jars with the patent wire snap, put the cover in place, the wire over the top and leave the clamp up.

The cover on a glass jar must not be tight while the product is cooking, because the air will expand when heated, and if the cover is not loose enough to allow the steam to escape the pressure may blow the rubber out or break the jar.

The product is now ready for the canner.

STERILIZING

If you are using the homemade outfit, such as wash-boiler or garbage pail, all berries and soft fruits are sterilized sixteen minutes; in all commercial hot-water-bath outfits and in condensed steam, sixteen minutes; in the water-seal, twelve minutes; in the steam pressure under five pounds of steam, ten minutes; and in the pressure cooker under ten pounds of steam, five minutes.  Do not allow the pressure to run above ten pounds for soft fruits; fifteen pounds makes them mushy.

If you use any type of hot-water-bath outfit be sure the water is boiling when the fruit is lowered into the canner, and keep it boiling vigorously for the entire sixteen minutes.  At the end of the sterilizing time, immediately remove the jars from the canner.