Interested in giving dry yeast a try and have a rehydration question. From the instructions on Danstar's website, it states that distilled or reverse-osmosis water should not be used. For those of us with water unsuitable for brewing, any suggestions for a rehydration water recipe (salts, yeast nutrients) starting with RO water? Thanks in advance.
We do not recommend to use distilled or reverse-osmosis water because the yeast would be damaged by osmotic pressure. Tap water contains minerals which lower the osmotic pressure on the yeast. You could rehydrate the yeast in a 0.9 % saline solution.
We have a nutrient specifically developed for rehydration of dry yeast called GoFerm. This nutrient is widely used in the wine industry and supplies the yeast with sterols and minerals during rehydration process.
Forbes & Tobias