YAN testing

[cmason1957]

I would think YAN would be very useful. There are some magic numbers out there that you want to hit with your Nutrient additions. Normally, I just guess and add whatever the package says to add per gallon. Having the numbers would allow you to make sure you add enough, without adding to much. It is best if it is all used up by the fermentation, so none is left over for bacteria to munch on and grow after the fact.

This link: Yeast Assimilable Nitrogen (YAN) - The Australian Wine Research Institute

Recommended YAN levels in grapes/musts/juices
Minimum YAN requirement for low risk fermentation:

• Whites – approx. 150 mg/L
• Reds – approx. 100 mg/L

YAN requirement for clean/fruity flavour:

• Whites – approx. 250 to 350 mg/L
• Reds – unknown (research in progress)

Maximum YAN demand:

• Mean = 400 mg/L
• Range = 330 to 470 mg/L

 

[tmcfadden932]

I would think YAN would be very useful. There are some magic numbers out there that you want to hit with your Nutrient additions. Normally, I just guess and add whatever the package says to add per gallon. Having the numbers would allow you to make sure you add enough, without adding to much. It is best if it is all used up by the fermentation, so none is left over for bacteria to munch on and grow after the fact.

This link: Yeast Assimilable Nitrogen (YAN) - The Australian Wine Research Institute

The best way is to use your nose. If you can smell hydrogen sulfide, rotten egg smell, then you haven't added enough. Some of the master wine makers, in and around Lodi, Ca. that I have talked to, recommend 225 to 250ppm in reds and about 2/3rds of that in whites with lower alcohol content.

 

[Rice_Guy]

Whites are the must which has the reputation for running short on nitrogen. Not reds. What would be the logic on using less on whites? ,,,,

The best way is to use your nose. If you can smell hydrogen sulfide, rotten egg smell, then you haven't added enough. Some of the master wine makers, in and around Lodi, Ca. that I have talked to, recommend 225 to 250ppm in reds and about 2/3rds of that in whites with lower alcohol content.

I talked to Vinmetrica today. * Their kit is the proper tool for running YAN on juice. * The test can be run with any pH meter with two place accuracy. My assumption is that yeast need similar nutrition any time they ferment. ,,, It will be interesting to see the YAN difference between reds and whites and several grape varieties.

 

[Tin_Man]

Hello all,

Attached below is one of my lab manuals that walks-you-through a YAN testing procedure using a Formol Titration. Hope it helps.
You'll need some basic glassware, a pH meter, NaOH, and 37% Formaldehyde (Formalin).

 

[tmcfadden932]

Those that are lucky enough to live near Lodi, Ca have the Wine Lab were a juice panel report is only $15 to wine club members. YAN is one of the components reported. Lodi Wine Labs - Analysis | Wine | Beer