Laffort’s Jillian Johnson DeLeon Outlines Strategic Yeast Nutrition and Fermentation Protocols
In an interview featured by Wine Industry Advisor, Laffort expert Jillian Johnson DeLeon detailed best practices for yeast nitrogen nutrition, fermentation timing, and early malolactic co-inoculation to prevent stuck ferments and control wine aroma profiles.
In a technical discussion on the Inside Winemaking Podcast featured by Wine Industry Advisor, Jillian Johnson DeLeon of winemaking product supplier Laffort presented operational strategies for managing yeast nutrition and fermentation dynamics in commercial winemaking.
DeLeon highlighted the primary structural differences between organic, amino-acid-based nitrogen sources and inorganic diammonium phosphate (DAP). To ensure complete fermentation, she detailed a two-addition nitrogen protocol tailored to yeast biological phases. The initial nutrient addition should take place within 24 hours of yeast inoculation—or at the first signs of cap formation in native ferments—to support yeast population growth. A second addition is applied near mid-fermentation to guide yeast to dryness while preventing hydrogen sulfide development. DeLeon recommended a dosing ratio of one-third organic nitrogen to two-thirds DAP for this second addition.
Total nitrogen requirements vary based on the specific yeast strain and its biomass production level. DeLeon explained that fermentation temperature directly impacts aromatic outcomes, notably shifting expression between esters and thiols. She warned that both under-dosing and over-dosing nutrients carry risks to fermentation clean balance and completion.
To manage spoilage risks and avoid stuck ferments, DeLeon advocated for early co-inoculation with malolactic bacteria. She also discussed field-tested Brix-to-potential-alcohol conversion metrics and provided an overview of Laffort's commercial offerings, which include oak alternatives and vineyard applications.
The featured discussion was sponsored by InnoVint, a developer of winery management operating software used to track vineyard metrics, manage cellar production processes, and automate compliance reporting.
Key facts
- Jillian Johnson DeLeon of Laffort outlined yeast nutrition strategies on the Inside Winemaking Podcast.
- A two-addition nitrogen strategy is recommended: the first dose within 24 hours of pitch (or cap formation in native ferments) and the second near mid-fermentation.
- The second nutrient addition utilizes a recommended heuristic ratio of one-third organic nitrogen to two-thirds DAP.
- Proper nitrogen dosing prevents hydrogen sulfide production and stuck ferments.
- Fermentation temperature influences ester versus thiol aromatic expression.
- Early co-inoculation with malolactic bacteria reduces spoilage risk and prevents stuck ferments.
- Laffort offers product lines ranging from vineyard applications to oak alternatives.
- InnoVint sponsored the episode featuring Laffort.
Why it matters
Efficient yeast nutrition management and fermentation controls are critical commercial parameters for wineries. Implementing precise nitrogen timing and co-inoculation techniques reduces the financial and operational risks associated with stuck ferments, spoilage, and off-odors like hydrogen sulfide, while enabling winemakers to predictably shape aromatic profiles.
- Wine Industry Advisor — 2026-09-22: “🎧222: Jillian Johnson DeLeon – Laffort”
This article was prepared by WBI.org from the sources listed above with the assistance of AI and reviewed by a WBI editor before publication. Information is attributed to its original sources.