Thanks to several players who did some extesive research last year we now know that you can influence the goods that will be offered in your new porduction town.
You have to generate a shortage of the first good to be offered the second good in the porduction town. Caveat: not all goods are given equal importance. If you are offered a good you don't want then increase the production of the associated good and check again. You actually can obtain all three goods to suit your Hanse.
Beer-IG
Ore-wool
IG-honey
Skins (furs)-fish
Timber – cloth
Honey – grain
Pottery – bricks
Salt – ore
Whale oil – grain + import of furs
Wine – pottery
Wool – wine
Fish – beer
Hemp – whale oil + fish
Pitch – hemp
Grain – meat/leather
Spice – no effect
Cloth – salt
Bricks – pitch
Meat/leather - timber