“Yeast derivative” is a term that is used to identify all the various products obtained from food grade yeast that have been inactivated via plasmolysis, autolysis, hydrolysis, etc. There are two main types: those where the soluble (yeast extracts) and insoluble parts (yeast hulls) are separated and those where these parts are not separated from each other (inactive yeast).
Yeast derivatives are very useful in winemaking thanks to their multiple uses which depend on the inactivation system used and the degree of protein hydrolysis, but also on the way they are separated and purified and their physical form (liquid, microgranulates, powder).
Laurence Van Nedervelde describes in his presentation the elaboration process and the enological interest of all the different yeast fractions in terms of absorbancy, tensoactive and colloidal effects, rigidity and permeability of the membrane and reactivity with tannins, etc.
Followingly, Etienne Dorignac highlights the different uses of yeast derivatives in winemaking and in particular the uses of the different physical forms and the different degrees of protein hydrolysis.
The seminars reproduced in these videos were presented at the 9th edition of Enoforum (Vicenza, Italy, 5-7 May 2015) in the session organized in collaboration with the company HTS Enologia-Fermentis
The video-seminar is conceived as a true professional update course lasting more than 15 minutes. Therefore, before starting to watch the video, we recommend that you prepare yourself for a uninterrupted session (ex. make sure you are free of all other engagements for the whole duration, turn off your cell phone and be equipped with materials to take notes).