English Other Poetry & Literature children's stories

In the fairy tale "The Ogre's Bride" (here is a slightly different version which can be read online: http://bit.ly/dTwAP ) retold by J.H. Gatty Ewing, there is a strange way of cooking hares:

By his daughter's desire the farmer now procured a large number of hares, and a barrel of white wine, which expenses completely emptied his slender moneybox, and on the day of the ogre's visit, she made a delicious and savoury stew with the hares in the biggest *pickling tub*.

Of course the story doesn't explain why she used a pickling tub to prepare a stew, but until today I had assumed a "pickling tub" was a tub for making pickles, not stew. Can anybody help me understand what it actually is?