variable volume Stainless steel tank

[Alon Philosof]

I'm thinking of using variable volume Stainless steel tanks with floating lid. these are widely common amongst wineries on a budget
and are relatively cheap. they can be found with either flat or dished bottom.
http://www.brouwland.com/content/assets ... 177801.jpg
Has anybody tried these with beer or have any strong arguments against using them?

Cheers,

Alon

[Moonlight]

I would venture that the wine is not carbonated, and a carbonated beverage such as beer, would not hold pressure in these tanks. I would also be concerned about air pick up which is more critical in beer.
Besides, aren't they more expensive than a solid tank?
Then again, wine tanks are not made to be as sanitary as beer tanks need to be. The polish on the welds is most often coarser so difficult to get as sanitary clean as one needs for beer. With the lower pH and higher alcohol wine is far less prone to spoilage from infection.

[Alon Philosof]

I would venture that the wine is not carbonated, and a carbonated beverage such as beer, would not hold pressure in these tanks. I would also be concerned about air pick up which is more critical in beer.
Besides, aren't they more expensive than a solid tank?
Then again, wine tanks are not made to be as sanitary as beer tanks need to be. The polish on the welds is most often coarser so difficult to get as sanitary clean as one needs for beer. With the lower pH and higher alcohol wine is far less prone to spoilage from infection.

In fact that are used in primary fermentations in wineries as well. they can handle some pressure. While these tanks cannot substitute brite tanks they can maintain the required positive co2 pressure in bot primary and secondary fermentations.
As for the welds, thats a matter of manufacturing and money. fittings can be easily replaced with sanitary ones.
I am told air pickup is minimal but I don't know whether it can be eliminated entirely.
Has anyone seen these in use in a brewery before?