Serac

The smoke found its way out of the holes in the roof as it liked best; and nearly over the fire was a black smoky shelf, supporting several masses of that inferior white cheese, called Serac.

Source: wiktionary

Here and elsewhere the sérac, which is something between curd and cheese, may be advantageously taken instead of butter, which is almost always bad.

Source: wiktionary

Note the Alpine cheese dairy on the Iseltenalp, where fresh dairy produce are made every day (milk, butter, cheese and serac).

Source: wiktionary

Perhaps the finest part of it [the Lysjoch] is the grand sérac scenery of the Zwillinge Glacier. In August, 1876, a party of four, having missed the right track in crossing this pass when the snow was in very bad condition, were carried down in an avalanche of loose snow probably started by their own weight.

Source: wiktionary