YAN: Building a Smarter Nutrient Management Strategy in 2026

With shipping costs continuing to climb in 2026, wineries and winemakers are feeling the pressure to make every dollar count.

If we agree that you want to make the best wine possible with varietal flavor, good mouthfeel, and representative of all of the work that went into growing the grapes this year… then measuring and adjusting YAN is one of the best ways to ensure success through primary fermentation. 

In Fermentation Nutrition: What to Know and Why to Know It (free, open content), you can see average shipping costs from the Eastern U.S. to Western U.S. for shipping small, 60-mL samples back in 2017. I’m sure that many of you, like many DG Winemaking Clients, are noticing generally higher shipping costs. This raises the question: is measuring YAN worth a shipping investment or a laboratory investment? 

Is measuring and adjusting YAN beneficial for you?

For DG Winemaking Clients who’ve already made that investment, they clearly find benefits in wine quality when they move away from blanket nutrient additions during primary fermentation: less hydrogen sulfide development, better varietal character development and retention, and easier, reliable fermentations overall. Nutrient decisions that are targeted rather than speculative create less wasted product, better quality fermentations and wines, and become habitual instead of momentarily difficult after a winery figures out how to incorporate this strategic analysis. 

Why is YAN Important?

Yeast assimilable nitrogen (YAN) or yeast available nitrogen (YAN) is one of the most critical components of grape juice/must composition for a successful fermentation and wine quality. Nitrogen is the primary nutrient yeast need to grow, reproduce, and complete alcoholic fermentation. Without adequate nitrogen levels, yeast struggle to complete fermentation or increase the likelihood of developing off-flavors by the end of fermentation. 

But YAN isn’t just about having enough; it’s about having the right amount based on the fermentation parameters. Additional factors that influence YAN requirements for a healthy fermentation include the starting Brix concentration (sugar concentration), yeast strain selection, juice/must pH, fermentation temperature, vitamins and minerals content, and the desired wine style. All of these components need considered in order to adjust the nutrient content during primary fermentation properly. 

Getting YAN into that optimal window is one of the most impactful things a winemaker can do for fermentation health and final wine quality. Too little nitrogen to support the fermentation, and the fermentation can become sluggish or produce off-aromas like hydrogen sulfide. Too much nitrogen in the juice/must and fermentations can race out of control, generate excessive heat, reduce varietal character, and produce hydrogen sulfide. 

*The ranges listed here are estimates and ballpark values. For different wine yeasts, the low, medium, and high ranges will alter. Recommendations also shift with changing Brix concentrations or with various nutrient suppliers. Always consult recommendations provided by your yeast and nutrient supplier.

What can you do to measure YAN?

For wineries that opt to measure in-house, the best option to measure YAN is through enzymatic assay kits. Enzymatic assay kits exist to measure both organic and inorganic nitrogen, the combination of which creates YAN. Challenges associated with enzymatic assays include:

• Purchasing a spectrophotometer.
• Purchasing support equipment such as micropipettes, pipette tips, and enzymatic assay kits.
• Having personnel that feel confident running enzymatic assays and using the spectrophotometer and can justify spending time on assays.
• Maintaining the shelf life of the enzymatic assay, which does eventually expire.

Nonetheless, integrating enzymatic assays into the winery provides the following benefits:

• Spectrophotometers can be used to measure multiple wine components including acetic acid, malic acid, phenolic concentrations, glucose/fructose concentrations (residual sugar) and more making it a versatile workhorse throughout the winemaking year.
• Enzymatic assays provide same-day results, which means winemakers can make nutrient addition decisions in real time rather than waiting on laboratory results.
• Using enzymatic assays is usually financially viable within one-to-two seasons 
• With more frequent use, winery employees become more confident and efficient in using the analysis.
• Over time, use of such analyses provides an in-house dataset. This proprietary knowledge about the fruit used to make wine is priceless: patterns emerge, decisions get smarter, and most winemaking decisions become proactive instead of reactive.

For wineries serious about quality and consistency, instruments like a spectrophotometer are less about luxury and more about a logical extension of a thoughtful winemaking program. Furthermore, companies like Megazyme have developed “mini specs” (the MegaQuant™) that make purchasing a spectrophotometer more cost advantageous for many wineries. 

What YAN assessment is right for you?

Back to our initial question: which YAN investment, shipping or in-house testing, is right for you?

When evaluating whether to ship samples to an external laboratory or invest in in-house enzymatic testing, wineries need to think beyond the per-sample cost and consider the full picture. 

External lab analysis offers high accuracy and no equipment investment, but shipping costs — especially cross-country — plus analysis cost plus turnaround time add up quickly, particularly during the crush season when decisions need to be made fast. In-house enzymatic testing requires an upfront investment in a spectrophotometer and assay kits, but the per-sample cost drops significantly at volume, and results are available same-day. A winery processing a handful of lots per vintage may find external labs perfectly cost-effective; a winery managing dozens of lots across multiple varieties and vineyard blocks, or a winery incorporating “off-season fermentations,” will likely hit a crossover point where in-house testing pays for itself within a season or two. 

The right answer depends on your unique situation: volume, geography, and how central YAN-informed nutrient additions are to a winery’s program.

Either way, the cost of measuring YAN – making room to do this – is almost always less than the cost of a stuck fermentation, a wine stripped of its varietal character, or a wine with a hydrogen sulfide problem.

For more information on YAN, YAN analysis, and manipulating the YAN during primary fermentation, please consider joining the DGW Elite Membership program as we have several resources that can help you make better YAN adjustments during harvest. 

The views and opinions expressed through dgwinemaking.com are intended for general informational purposes only. Denise Gardner Winemaking does not assume any responsibility or liability for those winery, cidery, or alcohol-producing operations that choose to use any of the information seen here or within dgwinemaking.com.