Making wine in galvanized milk containers

A. No, it's not, John. Zinc is not a food-safe surface; it is too easily soluble in too many things. Possibly including milk, but certainly including wine. -- but are you sure they are galvanized, not tinned? Copper pots, etc., have been tinned for a long time, and tin is food safe.

A. In many countries, hot dip galvanized containers were used to collect milk from dairy farms, to transport it to milk processing bottling plants. Originally in horse drawn wagons. This practice of using these containers must have ceased more than 30-40 years ago in most countries though. Milk being fairly neutral probably picked up little if any zinc, but your wine will be acidic at times and acid will dissolve zinc readily and become zinc rich.
While humans cannot survive without zinc, excessive amounts are also not good, and to be avoided.
Many of these old milk containers (about a meter high- 39", and hold perhaps 75 liters - 15 gal) still exist and could be seen as a useful container. Today much milk is collected from farms in road tankers with stainless tanks. Wine too is sometimes made in stainless.

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Thanks for the education, Geoff :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

A. Well if the brass plate is on the exterior, mechanical abrasion would probably be the best bet. You're not going to be able to remove that brass plate without stripping any galvanized coating underneath, regardless of chemical or mechanical stripping. Zinc is just too energetic about reacting with stuff.