why have I got zinc sulfate

[tubthumper]

I bought some zinc sulfate and according to the recipit it was in nov last year
howeve I have not brewed since then and was wondering why I got it
I hace googled and binged but no real results I can only think it was something to do with yeast harvesting or growing
anyone can throw any light on this please

 

[Vossy1]

I can only think it was something to do with yeast harvesting or growing
anyone can throw any light on this please

Yep, that's the one. All grain wort is often limited in zinc and it's very important for cell reproduction and other enzymatic activity.

 

[tubthumper]

now for the complicated bit
how much do I use

I wish I had kept the info on why I got it in the first place

was going to try and get the yeast from a bottle of the shelf as now seems to be lots of new bottle conditioned beers availible
so will see who has best yeast while testing them.

 

[Aleman]

Zinc is required for healthy yeast growth . . . . In the order of micrograms per litre.

How to use :hmm: :hmm: You need a very dilute solution

What you probably have is Zinc Sulphate Heptahydrate (ZnSO4·7H2O) which has a molecular mass of 287.53g and will contain 65.38g of Zinc Now if you put 1 g of zinc sulphate in a vessel and make it up to 1 litre you will have a solution with 65.38/287.53g (0.23g) of zinc in solution which is 227ppm (mg/l) zinc . . .remember I said that you need it in the order of micrograms so take 1ml of your solution and make it up to 1L you now have 227 ppb and if we go for say an additional level of 2ppb you have enough to treat 100l of brewing liquor

to treat a smaller volume say 40 L you need to add 400ml of your solution to the liquor to treat 5L for yeast culturing you need to use 5ml of the (second) solution


You pot of zinc sulphate will last some time :rofl:

 

[tubthumper]

thanks for info
now from that I can deduce that the amount I have will last me at least ten life times
it is 100g pack
zinc sulfate heptahydrate 98+%

so if any one is near croydon and wants some let me know