How to Choose Produce
In order to have the best canned product possible you will want to know how to choose your foods at the peak of their ripeness and then you will want to can them as soon as possible. You will not want blemishes or bruises on your produce. Be sure all the produce is washed very well. Then it will need to be cut up with knives.
Here are just a few fruits and veggies to give you some ideas on how to choose and prepare them for canning:
Apples: For applesauce, keep in mind that green apples make sour sauce, while overripe apples will make a bland, watery sauce.
Beans, green and yellow wax: beans wilt quickly after harvest so they need to be as fresh as possible at canning time. Beans need to be mature and crispy, but not woody or stringy. Trim off the stem end before using.
Beets: Best when they are around 2 to 3 inches in diameter. There a few types that will stay tender when they are larger and those can be canned as well.
Bell Peppers: Remove the stem, core, and seeds before chopping. Red, orange, and yellow bell peppers can be used interchangeably, however, green bell peppers have a unique flavor and cannot be used interchangeably.
Berries (blackberries, raspberries, dewberries, and similar): Need to be harvested in shallow trays or pans so that they are not crushed. Can berries the day of picking or quickly cool them to mid 30 degrees F. and hold at that temperature overnight.
Carrots: trim ends and peel them before slicing, grating, or chopping. Medium or small carrots are best; large carrots can have woody cores and a spongy texture that makes for soft pickles.
Cherries: need to be canned within four hours of picking; otherwise quickly cool them to mid 30 degrees F. Cherries should be picked when red-ripe, sound, and not overly soft.
Chile Peppers, Hot: If making preserves, you will want to remove the seeds from the peppers before chopping. Otherwise, follow the recipe instructions.
Citrus Fruits: Choose fruit that have a taut, shiny skin that feel heavy for their size.
Corn: Do not pick corn until you are ready to can it. It needs to be canned within 4 hours of being picked, before the sugar is turned to starch. If the corn is immature it will be watery and tasteless, if it is too mature it will be starchy and tasteless. Corn is at its peak ripeness when the kernels are milky, plump, and bright.
Cucumbers, field: Choose small or medium cucumbers that feel heavy for their size; larger ones tend to be softer and spongy. For best results look for field cucumbers that have not been waxed. Before chopping field cucumbers you will want to cut them in half lengthwise and scoop out the tough seeds before chopping.
Cucumbers, pickling: Use cucumbers up to about 6 inches in length (unless your recipe lists a preferred size). Use only firm cucumbers with no blemishes, splits, or soft spots. It is best to use pickling cucumbers within a day or two of harvesting.
Eggplant: Small or medium eggplants that feel heavy for their size are best. They should have tight, shiny skin. An overly large or wrinkled eggplant can be spongy and also can have very tough and bitter seeds.
Garlic: Use the freshest garlic possible. Heads need to be tightly closed and show no signs of mold or sprouting. If there are any green sprouts, they need to be removed to prevent a bitter flavor.
Gingerroot: Needs to be plump with shiny skin and no signs of rot or mold.
Gooseberries: Berries should be full-sized, but still green when picked. Should be canned same day as harvested. Otherwise keep them at 40 degrees overnight.
Greens (mustard, spinach, kale, & collard): Use young, tender leaves. Kale is best when harvested after a frost.
Herbs: Herbs need to be as fresh as possible. Just before using, herbs need to be rinsed well under cool running water. Pat dry with a towel or use a salad spinner to remove excess moisture.
Lima Beans: These are best when the pods are well filled and the seed is firm, but not hard.
Mangos, green: Green mangos are firm and tart. They will never ripen into sweet fragrant mangos. However, they can be peeled and cut in the same way as sweet mangos.
Mangos, sweet: When sweet mangos are ripe they have a fragrant aroma and the skin yields slightly to pressure when gently squeezed. Do not use mangos that are wrinkled or have soft spots.
Mushrooms: It is best to wipe mushrooms individually with a damp paper towel to remove any dirt. Do this right before using them. Best used for preserves as soon as possible after harvest. (Portabello mushrooms should be avoided in canning, they will turn any pickling liquid black.)
Nuts: Use only the freshest nuts possible. Nuts can be toasted before use for more added flavor.
Okra: Pods should be picked when they are around 2 to 3 inches long.
Onions: Onions need to be fresh and firm with no signs of sponginess or mold.
Peaches: Ripe but firm peaches feel heavy for their size and yield slightly to pressure when gently squeezed and have a fragrant aroma.
Pears: should not be ripened on the tree, ripening on the tree can cause pears to rot inside and they will spoil very rapidly. Pick pears when they are full-sized, a mature green, and when they are easily picked from the tree. Be sure to be gentle in order to avoid bruising or damaging as pears are quite sensitive and will spoil fast. Store the pears in cool place that is free of odors until they are ripe.
Peas: When they are mature enough to be shelled is when these need to be picked.
Plums: Need to be tree-ripened for the best flavor, with a deep color and a powdery bloom. Plums need to be canned quickly as they become over soft and mushy rather quickly.
Snap Peas: Need to be harvested when they snap readily due to crispness.
Tomatoes: Need to be firm and ripe. They should not have any bruises, spots, decay, molds, cracks, and/or growths.
Zucchini: Fresh zucchini has shiny, smooth skin, and no signs of decay or soft spots. If a larger zucchini's seed portion is soft you may want to remove it.