How to reduce H2S and DMS off flavours

Flavour Modification with Zetolite

It is well known in the brewing world that zinc and copper are required by yeast in trace amounts for cell growth, respiration and reproduction. They enjoy better viability and vitality when these compounds are present in the nutritional mix presented to the yeast.

Murphy & Son Ltd in conjunction with the Zetol Cooperation have developed a product called Zetolite that can be added to wort at the start of fermentation or to beer at the start of maturation to assist in the healthy growth of yeast and in particular to either prevent or reduce the incidence of sulphidic compounds such as hydrogen sulphide or dimethyl sulphide.

Zetolite consists of an aluminosilicate carrier, commonly called zeolite, which is impregnated with either zinc or copper ions. It is a pale pink/red or dark grey powder and is dosed at low levels. There are two types of Zetolite, 63 and 65 being copper and zinc respectively.

Zetolite 65

The zinc-based product, is dosed to wort prior to fermentation at a rate of 0.25 – 1.0g/hl. It prevents the formation of these sulphidic and sulphitic off-flavours/aromas.

Zetolite 63

The copper-based product and is dosed to beer at the end of fermentation or at the start of cold maturation. Dosage rates are typically 2.0 – 3.0g/hl. It may be so that sulphur-based off-aromas have been detected in the cold beer but with low temperatures, the brewer cannot wait the time necessary to naturally remove the unwanted volatiles. By dosing Zetolite 63 into the cold beer, the residual yeast is stimulated in the presence of the copper to metabolise the sulphur off-flavours quickly away.

We sell this product in 250g, 10kg or 20kg packs.

For more information regarding Zetolites please do not hesitate to contact frances.maud@murphyandson.co.uk