WINETECH Technical Yearbook 2020

TABLE 1. The metal composition of different stainless steel grades.

rusting of stainless steel. It is consequently recommended that a weak caustic soda solution is used for cleaning, followed by a water rinse, before it is dried. Stainless steel must never be left wet and must also be left open for ventilation. Apart from the cleaning of stainless steel tanks, it must always be remembered to leave the vents open before transferring wine from it to prevent the imploding of the tank (Szentpeteri, 2018). REFERENCE Szentpeteri, C., 2018. Steel yourself for double duty tanks. Australian and New Zealand Grapegrower and Winemaker , September 2018: 60-62.

Grade Chromium % Nickel % Molybdenum % Carbon %

304

18,0-20,0

8,0-10,5

–

0,08 max

304L

18,0-20,0

8,0-10,5

–

0,03 max

316

16,0-18,0

10,0-14,0

2,0-3,0

0,08 max

316L

16,0-18,0

10,0-14,0

2,0-3,0

0,03 max

water is not left in stainless steel tanks. Depending on its salt concentration, it can especially during the summer months evaporate and concentrate the salt con­ centration in the remaining water. This creates an environment that will cause the

and price advantage. If larger tanks are preferred, it is recommended to use stronger duplex types. The cleaning and maintenance of stainless steel tanks are essential to extend their lifetime. It is important that untreated

unnecessary in most cases, because the ullage space is usually filled with inert gas. Although both grades are acceptable for wine cellar tanks, unless high acid concentrations are stored, 304 is usually preferred as a result of its characteristics

WINETECH TECHNICAL YEARBOOK 2020 167