When To Harvest Basil
If you prune your culinary basil plants often (see the care section), you can expect to get from 15 to 20 cups of leaves from each plant over the season. That's a fair amount of pesto.
Basil foliage can be harvested as soon as the plants is 6 to 10 inches tall, about 6 or 7 weeks after the seeds have been sown. Start pinching off individual leaves as soon as the plant can spare a few. Most culinary herbs are best picked early in the morning just as the dew evaporates. Picking the youngest shoots gives best flavor and helps keep the plant pruned. Cut just above a leaf nod where the leaf stem joins the main stem.
Basil will change its flavor late in the season when days get shorter and temperatures cool. Basil addicts will avoid this problem by starting some new plants in August and bring them inside as houseplants just before first frost.
You can dry basil in a dehydrator or in the microwave oven. Air drying works if you live in an area of the country with fairly low humidity. The foliage from one full-sized plant, dried and stored in an air-tight container, will yield a year’s supply for most families, unless like most of us you fall in love with pesto (see cooking section). The general rule for all kitchen herbs however, is that they should not be stored for more than six months before being thrown away and replaced.
There are several ways to store basil. Fresh basil foliage is best used immediately, but will keep for several days if it is stored while still on its stems in a jar of water covered with a plastic bag in the refrigerator. Fresh basil leaves can also be stored in olive oil, yielding a pungent cooking oil.
Frozen in plastic bags it retains its flavor but becomes discolored. It also freezes well when ground and mixed with butter or oil.