….AND ABSTRACTS: STAINLESS STEEL IN THE WINE INDUSTRY

50 Years Ago

Surface Finish and Ease of Cleaning

  1. TROOST and K. FETTER: Stainless Steels in the Wine Industry with Special Reference to their Surface Condition. Weinblatt, 1966. Vol. 61, No. 35-6, pp. 797-801.

The study forming the subject of the paper was undertaken in the context of the growing use of chromium-nickel austenitic stainless steels in the German wine industry.  Four grades of steel – 18/10, 18/10 Ti, 18/12-2.3 Mo and 17/12-2.3 Mo-Ti – have been found particularly satisfactory and tanks storing wine at atmospheric or high pressure at temperatures ranging from -5 to +95 degrees Centigrade have been in use since 1953 with no sign of corrosion.  An important advantage of stainless steel in this application is that it has no effect on the taste of the wine.

Because ease of cleaning of tanks is important, the authors investigated the effect of surface finish on the amount of tartar deposited on such steel, its adhesion and the ease with which it can be removed by cleaning.  Specimens in eight conditions of surface finish, ranging from highly polished to hot-rolled, heat-treated and pickled, were suspended in a 6000-l must tank during fermentation, and the tartar deposit was weighed and the ease of cleaning by spraying and washing with water assessed.

It was found that the amount of tartar deposit increased with surface roughness and that the deposit was more easily removed from highly polished surfaces.  This type of surface is, however, the most expensive to achieve, and not economically viable, and the authors therefore suggest that the surfaces of fittings and pipelines should be polished to 320-180 grain and that sheet for tanks should be used in the cold-rolled, heat-treated and pickled condition.

Stainless Steel magazine May – June 1967