Direct yeast inoculation
Direct yeast inoculation involves adding yeast directly to the must without prior rehydration. This method simplifies the fermentation process by eliminating the rehydration step.
What is direct yeast inoculation by Oenobrands?
We have pioneered this technology to help winemakers achieve consistent, high-quality results with every batch.
The story started in 2010 with the observation that poor rehydration of Active Dry Yeasts (ADY) might result in a slow or even stuck fermentation, which in turn will have an adverse effect on wine quality. In addition, this stage is time-consuming and prone to mistakes since something as seemingly harmless as yeasting may have a significant impact on cellar productivity and wine quality.
As an answer, we wanted to modernise this process for performance and repeatability. After the first trials, we concentrated on yeasts and how to make them more robust. And this is how the In-Line Ready yeast production process was developed: an adapted In-Line Ready recipe for dry yeasts, putting them in their optimal physiological state for the direct addition conditions that allow us to launch Fermivin In-Line Ready (ILR) products.
Introduced in 2013, the In-Line Ready Fermivin yeasts have been meticulously developed to resist direct inoculation while maintaining high viability and activity in the must.
What makes In-Line Ready Fermivin unique?
The key to In-Line Ready’s popularity is its distinctive multiplication and production process. This tailored approach strengthens the yeast, making it more resistant to the stresses experienced during direct addition, such as low temperatures and acidity. The result is a yeast that is more viable and adaptable than the classically produced corresponding yeast that is directly added. Also, this process makes yeast able to handle the challenges of fermentation with similar speed as matching Fermivin yeast, classically produced and added after a rehydration protocol.
How does direct inoculation affect wine quality?
Fermentation Consistency
Any research we conducted on fermentation kinetics demonstrated the performance of In-Line Ready Fermivin yeast.
We report results on whites, reds, and rosés wines that demonstrate similarities in viability and fermentation kinetics of ILR Fermivin yeasts put directly vs. the same yeast grown classically and inoculated after rehydration.
We show you here various results on various grapes and types of juice, meaning also various Fermivin strains available in classic and In-Line Ready production.
Fermentation monitoring of wines comparing In-Line Ready (ILR) Fermivin yeasts directly inoculated to the same strain, classically produced and added after rehydration.
QUALITATIVE WINES
Over the years, when we compared wines made with In-Line Ready (ILR) Fermivin yeast to those made with classic Fermivin yeasts added using a rehydration protocol, the aroma profiles were similar, whether we looked at them analytically or organoleptically.
- Focus on colour
The visual appeal of red wines fermented using In-Line Ready (ILR) Fermivin yeasts is somewhat different. These wines have a tendency to have more intense colours, bluer and violet hues, and a little different colour overall.
When compared to the corresponding classic Fermivin yeasts added after rehydration, this result demonstrates how direct inoculation influences the appearance of the end product.
- Focus on aroma
Our studies confirm that In-Line Ready (ILR) Fermivin yeasts produce wines with the same aromatic palette as classically produced Fermivin yeasts, as observed by users for over 10 years.
They do, however, highlight certain minor variations, primarily in terms of overall intensity and traits related to the grape variety.
Following this comment, we tested it by comparing In-Line Ready yeast production to standard production added after rehydration for different Fermivin strains in different conditions.
For Sauvignon blanc, we used the TS28 strain, which produces varietal thiols (3MH and 4MMP). Under our conditions, we observed a trend to have a higher amount of 3MH when the TS28 strain was used in the In-Line Ready (ILR) form with direct inoculation than when it was used in its classic form inoculated after being rehydrated.
For Chardonnay, we compared yeasts that produce high ester levels, namely the IT61 and AR2 strains. When the strains were used in In-Line Ready (ILR) production and direct inoculation, we didn’t observe any significant differences in terms of fermentative ester production, but the differences between strains were obvious.
Technical considerations for direct addition of In-Line Ready (ILR) yeasts:
- Inoculate the chosen ILR Fermivin yeast at 30 g/hL.
- When filling the fermentation tank.
- For red winemaking, you can also add the ILR yeast at the reception desk, when filling the tank with the crushed grapes, or at the top of the filled tank.
- The temperature of the juice inoculated with the ILR yeast must be 15°C or higher.
- The addition of Extraferm® D’tox helps to manage the turbidity level and its specific composition helps to maintain the viability and fermentative power of the yeast. We recommend a dose of 20 to 40 g/hL at the same time as the ILR yeast. The lower the turbidity, the higher the added dose.
- Carry out standard pumping over of the must for better homogenization of the yeast.
- To provide a high content of free amino acids in the fermenting must, we recommend you add Natuferm® Bright in white and rosé must and Natuferm Fruity in reds at a minimum of 20 g/hL.
Choosing the right yeast for direct inoculation
- Can I use any type of yeast for direct inoculation?
Not all yeast strains are suitable for direct inoculation. It’s important to use strains labelled In-Line Ready Fermivin, which are specifically developed for this purpose.
- What strains are available in In-Line Ready form?
Certain Fermivin strains are available in both classic and In-Line Ready forms. Initially, each Fermivin strain is selected for its fermentation characteristics and aromatic profile. When selecting a yeast strain, consider the wine style, the fermentations conditions, the desired aroma and flavours and the pack size of the product.
| Product name | Type of wines | Wine | ILR pack size |
|---|---|---|---|
 | Very aromatic fresh, green and crisp wines | W, Ro | 500 g |
 | Intense tropical with volume | W, Ro, C | 500 g |
 | Green and crisp thiol style wines | W, Ro | 500 g |
 | Mouthfeel & elegance for premium whites | W | 500 g |
 | Fruity round white and rosé wines | W, Ro, Sp, C, F | 500 g |
 | Intensely aromatic white and rosé wines | W, Ro, C, F | 500 g |
 | Premium dry white wines | W | 500 g |
 | Mineral, crisp and aromatic whites | W | 500 g |
W: white, Ro: rosé, Sp: Sparkling, C: cider, B: Brandy, F: Fruit wine
| Product name | Type of wines | Wine | ILR pack size |
|---|---|---|---|
 | Coloured concentrated fruit-forward red wines | R, Ro | 500 g |
 | Fresh & clean red fruit aromas | R, Ro | 500 g |
 | Mid-palate fruity structured red wines | R | 500 g 10 Kg |
 | Early release fruity red wines | R, Ro | 10 Kg |
 | Multipurpose yeast | W, Ro, R, Sp, C, F | 500 g 10 Kg |
 | Fruit wines and distillation | W, Ro, R, B, F | 500 g |
W: white, Ro: rosé, R: red, Sp: Sparkling, C: cider, B: Brandy, F: Fruit wine
Discover the FERMIVIN range
What about you?
With a highly qualified team of experts in many fields, Oenobrands strives to offer winemakers’ novel and scientifically sound solutions, as well as to highlight the positive synergies between its products.
Search your solution or product
Tell us about your difficulties, and we will answer you