I have a hard time keeping basil.
When I buy it from a local grocery store, it is perfectly fresh, but when I take it home it withers in a couple of days.
I have tried keeping it in fresh water and trimming the stems, but that only extends its life about 48 hours. My current record is 3 days before it goes bad, and I only got that by trimming and replacing water every 16 hours.
What is the secret here? How can I keep the basil alive?
Don't try and keep it alive. Wrap it in plastic wrap and freeze it. It will thaw in seconds under running water. Freezing will do little harm to the flavour.
I have had more success with basil that has the roots intact, placed in a tall vase and completely changing the water every 2-3 days, and lasting as long as two weeks. When that's not available, I can make it last 4-5 days by separating the bunch, trimming much of the stem, and spreading it on a long sheet of dry paper towel, rolling loosely, placing in a plastic bag and keeping in the frig. Mind you, the second method is not always successful. If I'm planning to cook with it, I run it through the food processor with just olive oil and keep it in a container in the frig, drizzling a bit of oil on top to prevent darkening.
