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Wine Yeast Assimilable Nitrogen (YAN)

Yeast Assimilable Nitrogen (YAN), also known as Formol Number, is a measurement of Nitrogen in wines. Nitrogenous compounds such as ammonia are essential to the winemaking process. A sufficient concentration of nitrogen must be present in the grape juice for healthy yeast metabolism and an efficient fermentation. Low nitrogen levels can result in slow or incomplete fermentations. When nitrogen availability is too low in wine must, yeast may undergo less efficient, undesirable fermentation pathways possibly yielding hydrogen sulfide, a compound known for its ‘rotten egg’ odor

Typical nitrogen levels in grape must should be between 140-500 mg/L. Nitrogen can be supplemented with the use of diammonium phosphate (DAP), an Alcohol and Tobacco Tax and Trade Bureau (TTB) approved ammonium-based wine additive.


Titration Systems

A variety of titrations systems are available including one that is programmed with only wine methods including yeast assimilable nitrogen (Formol Number), total titratable acidity and free and total sulfur dioxide. Titration systems are available with 1 or 2 analog input boards that allow multiple sensors to be used. These systems can also be configured to have one or two dosing pumps. Having multiple dosing pumps allow for the use multiple titrants.

For high throughput some of the titration systems can be connected to an auto sampler for automated analysis of multiple samples.



Mini Titrators

Hanna Instruments pioneered the innovation of mini titrators for customers that were performing the formol number titrations manually to be able to use an automated system at a fraction of the price of the titration systems.

The mini titrators offer the precision of dosing by a syringe with the ease of pre-measured reagents and pre-standardized titrants.





A variety of pH electrodes are available that include application specific versions made specifically for grape juice and must. These versions feature a ground glass junction with a plastic sleeve. These features are part of Hanna CPS (clogging prevention system) technology to prevent clogging of the reference junction by solids found in grape juice and must.





Accessories include the spare parts for the mini-titrators. These include the replacement tubing with valve, syringe, beakers and stir bars.


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