WATCH & QUESTION: Trading town

Schouwen and Duiveland used to be two islands. A wide creek called Gouwe flowed between them. Ebb and flow created tidal creeks. One of these creeks ended in the Schouwen country at Brijdorpe, then a village with a church. When the polder was embanked in the 12th century, a dam was placed in the creek and a sluice was built in the dam to drain the polder water. A village had to be built around that dam. Brouwershaven was built on the dikes.
Brouwershaven grew into a beautiful little town where a lot of trade was done. Barrels of herring and madder (for the red dye) were loaded from the market into the ships in the harbour using a wooden crane and transported to Brabant, Rotterdam and Antwerp, among other places. But mussels, shrimps and beer also made a lot of money. And at the scales, people weighed grain, flour and metal. Nowadays, there is not much trade, but the remains of this trading town are still present and clearly visible.
Question 1: What was mainly in the barrels that the wooden crane moved around the market? Madder and ... Write down the 1st letter.