“You just opened up an old can of worms that fosters a lot of debate on these forums. Prepare for sh!t to hit the fan soon.
To sum up the argument, modern Americans and old and new Europeans have different understandings of these terms, with Americans focusing on type of yeast and Europeans focusing on process used.”
Most beers marketed as Kölsch taste nothing like Kölsch tho. And they definitely can’t call it a Kölsch, at least until Brexit maybe. I can find no mention of “Steinfurter” being a thing, other than in this case. Several places call it a Köln/Cologne-style beer…
Given the origin of the beer (in the nearby of Münster) and the description you made, looks like a Münsterländer Altbier, even if not sour. (maybe the one you are referring to had not secondary fermentation).
" Heavily-hopped, beers of 12-18º Plato.(…) Münsterländer Altbier were the best-known beers of this type. They became sour much like Porter - through a long secondary fermentation. Bacteria in the lagering vessels slowly changed the beer’s character. They needed to be stored for at least a year for this process to take place. At the end of the primary fermentation the beer it was not sour at all. The only beer of this type to survive is Münsterländer Altbier - stilll brewed by Pinkus Müller in Münster today."
Otherwise, always from the same source, maybe a Keut
As early as the 16th century Münster) was a renowned brewing centre. The main product of the town’s breweries was Keut , a beer brewed from wheat, barley and hops. During the 1500’s it had gradually pushed out the older Grutbier (or Grussink ). In 1591 the town boasted 56 Keut brewers, who exported as far as Emden, Osnabrück and Ravensberg. The trade became a major source of income and local officials checked the quality of every barrel before it left the town gates.
Keut Keut had developed in the low countries during the late Middle Ages, where it was called " Koyt " or " Koit ". It was originally unhopped, being flavoured with a mixture of herbs called “gruit” (or “grut”) and brewed from a combination of oats, wheat and barley. In the Netherlands, beer firm Jopen markets a Koyt inspired by a 15th century recipe from Haarlem.