The use of direct inoculation yeast is less effective and safe than rehydrated yeast

Since the development of active dry yeasts for wine in the 70’s, to get the best of them, the best practice has been to rehydrate them in water at 37 °C for a short time, before inoculation of the juice or must to be fermented.

However, there is a new trend for so-called “direct inoculation” dry yeasts that are now appearing on the market, supposedly without the need for rehydration. And understandably so, winemakers might be tempted by this ease of use.
But the use of direct inoculation yeast is less effective and safe than rehydrated yeast.
We conducted numerous rigorous experiments to compare these yeasts with “conventional” WADY (Wine Active Dry Yeasts) for which rehydration is recommended