I don't know any, but If I may give you an advice, get lost there. As a reward, you will see considerably more of old Venice life rather than other tourist backpacks.
Hope you have more than one day for visiting Venice also, it is worth it. I spent a week there and I still feel I missed much. Although I went in single and out engaged, so I guess I did not missed that important stuff.
So I just got back today and...I found a shop .
It is called Degani and you can find it in the right corner of San Marco Square. Some fairly inflated prices but so is the gin&tonic in sold in the square (25 euros!!!).