Only possible thing I can think of is that they are meant to be harvested young, but I don't know the variety. Was there a particularly long time between pulling them?
The only experience I've got in growing carrots in containers was Amsterdam forcing. I was quite disappointed in the taste as I could swear it was soapy.
The early outdoor ones (Nantes) are also a bit soapy if you eat the thinnings but get sweeter as they get bigger. This is the logic behind baby veg seed - they are bred to get the sugars earlier than they normally would, hence tasting mature when they're still tiny. After that they lose it again. My baby sweetcorn are awful once they get too big. Woody tasting.
Perhaps there's an optimum window with the carrots - outside which you get nasty tasting veg?
Just guessing...
moonbells
