When I buy a bag of carrots, some taste sweet and some taste like they'd been stored in Courtney Love's closet!
Answers:
carrots are weird little things. you know how there's a darker center of the carrot? that's vascular tissue and some structural cells. the outer lighter part? storage for sugar - this is the part that tastes deelicious.
things i suspect that are going on:
1. some farmer's market carrots are called 'cored' carrots because that center is so bad and tough you must discard it before eating the rest. lots of folks don't know about this. they're like carrot varietal sneaker bombs.
2. carrots in the grocery store, like most things in the grocery store, are bred to produce something beautiful instead of something that is tasty (see: tomatoes). big, straight carrots are grown in an environment that doesn't stockpile sugars well. keeping carrots unrefrigerated, in bags, and machine-washed all contribute to aerobic conditions or bacterial growth, things that decrease sugar content before they get to your mouth. older carrots have more time to use their stored sugars or develop bacteria that will.
here's what i think you should do.
avoid the regular old carrots. every grocery store sells them - the variety is imperator - and they're bred for size, not flavor. try to find any carrot that's not regular old. you'll probably have the most luck with nantes.
buy carrots that are cold and from somewhere nearby. dig for the ones on the dark, cold bottom of the display, especially if they still have their greens.
don't ever buy bagged carrots. (p.s. - baby carrots are just the same giant, tasteless carrots cut up. i know. i cried when i found that out, too).
if you buy carrots at the farmer's market, ask for samples and ask if they're cored. also try to go for shorter, chubbier carrots. i like to think those guys invested more energy in producing sugars than producing length. i don't have literature to back this up, but it hasn't failed me.
look at quality before purchase