The main producing areas salts in Northern Europe were Luneburg, the Low Countries, and Lincolnshire in England, during the early C14th and were very similar in quality. However the type of salt at each area was different. At Luneburg, the salters boiled their brine over fast burning fires, which produced small-grained salt. In the Low Countries and Lincolnshire, a slow burning process was used and the resulting salt was large-grained. All of these productions were synchronised with the herring season, this resulted in salt being produced virtually all summer.
England is said to have had lower production costs than others and so could export more cheaply. Evidence for this in the C14th is however meagre. All that is suggested is that the producers only traded within their spheres of influence. In the C14th the Baltic was niether a market for foreiegn salt or a source of foreign supply. With the Baltic virtually closed to trade by sea, the salt from the Low Countries travelled in other directions, But very little appears to have gone to England. England was also a large exporter of salt at this time(mid C14th), to Norway, Zealand, Flanders, Normandy, and Germany. This is supported by the fact that output from England was £500 - £600 a year, while import was only £80 - £90.
After the mid. C14th, the potential market for English salt expanded greatly, as the Low Countries began to realise their indigenous supplies were not endless. Also Luneburg, was falling in exports, as the expanding port of Danzig was penetrating the markets of Poland and Russia. By the end of teh C14th Luneburg was less able, or willing, to supply salt adequately.
In 1370, the 'Treaty of Stralsund' secured the freedom of the sound and so the sea-route to the Baltic was thus open. However England could not produce this salt, as there was a rev. in England which had diverted salt-makers to cloth production and economic life had changed, as wages had gone up. This affected the English salt making in two ways:
By the late C14th, western Europe was no longer able to supply itself from the established salt making regions. The Baltic ceased to be self-suffient, and England and the Low Countries began needing more salt than they could produce.
In the early C15th, Denmarks disruption and wars in the Baltic, had caused piracy. Thus salt trade was organised into convoys. The biggest of these Northern traders was 'The Bay fleet', which travelled from the Hanse, to Bourgneuf Bay. It contained both Hanse and Non-Hanse owned ships, and some sailed on to La Rochelle and Spain. In addition to this a Dutch fleet follwed, and began to rival the Hanse fleet, as the principle cargo for the Dutch was salt. Bourgneuf Bay quickly became an important salt market and an entrepot for neighbouring regions.
From Bourgneuf Bay the fleet sailed North to the Low Countries, eg. Middleburg, Antwerp, and Bruges. The fleet then carried on north to Scania, but mainly Danzig, Riga, and Reval, where great salt markets were set up. The salt was usually sold loose and distributed from entrepots by sea.