How Oculyze yeast cell counter works? Watch video demo!

Five minutes in the lab
can be more important
than five days in the field

Worldwide shipping available from our online store

Five minutes in the lab can be more important than five days in the field

Worldwide shipping available from our online store


Stuck or sluggish fermentation affect
up to 20% of the global wine fermentations

Stuck or sluggish fermentations occur in the cellar. The yeast struggle to convert sugar to alcohol and carbon dioxide (sluggish) or become completely dormant (stuck).

This can cause a myriad of problems:

  • Bacteria can take over the fermentation, resulting in off-flavors

  • A wine destined for dryness will not be able to finish fermentation without adding additional yeast, leaving residual sugar and leading to undesirable sweetness

  • Oxidation, resulting in off-flavors

  • Dead yeast/autolysis and the consequent off-flavors

It can occur for a number of reasons including:

  • Insufficient living yeast cells at the start of fermentation

  • Insufficient nutrients (e.g., nitrogen deficiency)

  • Poor inoculation technique

  • Lack of oxygen at the start of fermentation

  • Sugar levels are too high

  • Alcohol level is too high

  • Temperature too cold or too hot

  • pH is too low

  • Biochemical communication: bacteria affecting yeasts’ ability to consume sugar


Oculyze Fermentation Wine

Oculyze offers a smart, technology driven solution to the age-old problem of manual yeast counting and is now automating yeast analysis for hundreds of customers in over 40 countries.

Oculyze Fermentation Wine (FW) combines a 400x optical magnification with cloud-based image analysis software to enable you to accurately, easily and instantly analyze yeast concentrations onsite before and during the fermentation process. No special expertise or training is required.

Yeast cell counter is a very small investment to ensure your vintage achieves the potential of your grapes. You can’t control the sun or the rain, but you can control your fermentation.

Oculyze FW

Oculyze FW automated cellcounter was designed specifically with and for vintners. The automated yeast counting system determines concentration and viability helping winemakers to control their yeast by increasing reproducibility and removing human error. and it does so for a price well below the competition.

The Oculyze FW is a small investment to ensure your must reaches its full potential and significantly more affordable than benchtop cell counters.

Learn how to prevent stuck fermentations with FWC!

Are you interested in downloading our cell counter market comparison?


Key Features

  • Oculyze FW helps improve quality and consistency in your wine-making process

  • Concentration and viability analysis in less than one minute

  • Quick and easy to use and delivers accurate and immediate on-site results

  • Assists winemakers understand the progression of their fermentation so they can identify and rectify problematic fermentations at the earliest possible stage

  • Automated warnings will automatically interpret the data and warn you of potentially stuck fermentations – Coming soon!


We analyze the same volume as in a counting chamber (hemocytometer) but are 10 times faster and have no human error. Additionally, yeast viability is determined by differentiating between live and dead cells with methylene violet staining.

An integrated separation of clumped cells allows an accurate analysis; budding cells are automatically identified and provided as a separate value.

Our data management system allows you to access all of your yeast concentration and viability results. Review your analysis history from anywhere, anytime.

View and analyze your measurements from any connected device. The web app allows you to generate customized reports, view historical data, track your yeast over time and increase statistical accuracy by creating averages of different measurements.

Additional features

Methylene violet in wine fermentation

You can choose between Methylene Violet and Blue for your viability measurements. We send methylene violet with every purchase. Methylene Violet can offer advantages; it performs better in growing phases of yeast cells (i.e. exponential and stationary) as well as for cultures with low viability and totally dead cultures.

Sharpness indicator in wine fermentation

This feature improves image quality and helps guide you to find the sharpest possible image. As you begin your measurements and turn the microscope knob, you will see the sharpness indicator changing values, once you have found the highest value possible – you’ve found your sharpest image and you’re ready to capture!

Manual Counting

Oculyze FW includes the option to manually count your yeast. This function adds a counting grid to your yeast images to mimic a hemocytometer/Thoma Chamber. This also affords you the opportunity to see what other microbes are in your must!

Discerning Cells

The Oculyze analysis will report on the varying sizes of your yeast. In addition, the algorithm will also identifying the percentage of cells that are budding which can be an indication of good yeast health as well as the stage of fermentation. Finally, Oculyze analyses can identify clustered cells, a task most automated cell counters struggle with.

Thoroughly tested

“The results of the cell counting with the Oculyze system are very closely comparable with those obtained using a Thoma chamber… The Oculyze system does not require a laboratory microscope or trained staff… The Oculyze system is faster due to the automated measurement and analysis.”External validation by the Research and Teaching Institute for Brewing in Berlin (VLB)
Complete report as PDF

What is included in every fermentation wine (FW) package?

  • measuring cylinder
  • methylene violet
  • pasteur pipettes
  • reaction containers
  • cleaning cotton swabs
  • sample chambers
  • plastic syringes
  • bellows

Online Store
  • Oculyze FW
  • Sturdy compact case

Automated yeast analysis for wine fermentation
without the high price tag

Starting at 999

Suitable for Large Wineries

Unlimited Pro

  • Prepay unlimited analysis for 12 months
  • Get the microscope for free!

Suitable for Moderate Wineries Most Popular!

500 Analyses

  • Prepay for 500 analyses
  • Get the microscope for half price!

Suitable for Small Wineries

Oculyze FW

  • Oculyze Fermentation Wine microscope
  • 15 FREE analyses!
Please send me more information

Gold Medal winner at Intervitis Interfructa Horitechnica (IIH) 2018

Oculyze was awarded the prestigious Gold medal for its enhanced technology at the 2018 IIH held in
Stuttgart, Germany.Winner: Innovation Prize 2018

Prevent stuck fermentations

To learn more about stuck fermentations download article or if you understand the problem already visit our webshop!

To prevent stalled or stuck fermentations and avoid risking the contents of an entire tank or vintage it is fundamental to control the fermentation on a daily basis. Commonly this is done by refractometers and density meters. The challenge with these methods is that density follows the metabolic activity of yeast and if you wait for your sugar content to deviate from your expectations your fermentation is already sluggish if not stuck. By means of a microscope, counting chamber and staining agent you can keep an eye on your yeast population, allowing you to react early to fermentation problems- if you are experienced enough to spot them. Determining concentration and viability requires a lot of practice There is quite a bit of subjectivity involved when it comes to counting cells and determining viability. Which is why the analysis should be conducted by the same person every time. One of the main reasons wine makers stop doing this time consuming analysis is that the manual measurements vary so much that the results cannot be trusted from one measurement to the next- let alone from one year to another. This problem can be solved by automated cell counters for yeast but besides being expensive they are not desinged with wine makers in mind. Do to its very rich microbiologial diversity wine fermentations are particularly interesting and challenging.

Figure: Example comparison of stuck and normal fermentation and problem detection time frame by method

Figure 1 shows 2 yeast concentration curves (orange and dotted orange) and two density curves (blue and dotted blue). While the dotted lines show how a normal fermentation without problems would have developed, the colored lines show a stuck fermentation. Starting from day 3 onwards problems with the yeast become visible via the Oculyze FW-C (magenta bar), around day 7 these problems can be detected via traditional density meters (grey bar). Using Oculyze FW-C the problem will be detected up to 6 days earlier than by only analyzing the density. The FW-C prediction models use a combination of yeast parameters including viability (not shown in the graph above), as well as the density readings.

Fermentation Wine Consultant (FWC)

Another challenge in tracking fermentations the old fashioned way is that even if you have an accurate cell count it takes many years of experience to interpret the value and correlate it with temperature, pH and density.

Oculyze’s FWC cloud based Artificial Intelligence (AI) models bundle years of research and must related data to give the wine maker a tool that not only provides raw data about yeast but puts it in context of the fermentation – just like a consultant would.

FWC enables wine makers to quickly interpret the results of their cell counts by means of warnings if something seems to be off. They no longer need 20 years of experience to know what the cell concentration means for them, they now have a tool in their hand to prevent stuck fermentations.
You can’t control the weather but with FWC you can control your fermentations. You can order the FWC-addon to your Fermentation Wine cell counter here.

Looking for more information?
Click one of the links below.

Article: Viability and Vitality in
Click here
Article: Stuck and Sluggish Fermentations and the Canary in the Coalmine
Click here
Article: Yeast monitoring helps to reach the full potential of wine
Click here