Lesson learned on yeast nutrient

[joea132]

I'm currently still fermenting a cabernet that started around 26 brix. Added my yeast and let it get fermenting nicely. At about 1/3 fermentation I added 1g per gallon of fermaid k. Having had that be enough in the past I didn't think about adding any more. My fermentation slowed almost to a stall around 5 brix. I reluctantly added another .5g per gallon and watched the fermentation take off again.

The takeaway:
High brix must needs more nutrients to help the yeast consume the high sugar content. I fell into the "this always worked for me" attitude and almost stalled. Most nutrients suggest considering a second addition around 2/3 sugar consumption. Rule of thumb is not to add nutrients after that point but I had no choice. Now I'm waiting for my brix to come down to 1 so I can press it off the skins and not have too many tannins imparted. I thought you might like to know my learned lesson. Winemaking is a very humbling hobby!

 

[joea132]

By the way early detection, understanding, and quick action meant my wine still has a clean nose and no unusual tastes.

 

[Julie]

Thanks Joe, that is good tidbit to know.

 

[Boatboy24]

Thanks for the lesson, Joe. That just confirms: while many fermentations are very similar, no two are ever the same. And like you said, just because something worked in the past doesn't mean it'll work today.

 

[JohnT]

I am convinced that yeast cells are psycic and vindictive. They can sense when you need an attitude adjustment.

Great lesson. No amount of knowledge can replace simply staying on top of what is going on during fermentation.

 

[ibglowin]

Fermaid-K instructions do say add the full amount at 1/3 sugar depletion. I have been adding 1/2 the dosage at 1/3 depletion and then the other half at 2/3 depletion.

Only been making wine from fresh grapes for three years now but so far this addition regimen has worked well with no stuck or sluggish fermentations.

The biggest test was my Petit Syrah that I will press this AM. It started out at 26 Brix and finished out to 1.000 without incident (on two separate yeast strains).

 

[Rock]

Well you should be adding your first dose at lag phase then again at 1/3 sugar depletion.

 

[oldwhiskers]

I have been noticing the same thing recently on a few batches. I had just determined that I would be adding more at the 2/3 mark from now on to push it on over the finish line without coasting to a stop or stalling before getting there.

 

[altavino]

fermaid should be added just after lag phase , at the first signs of a cap forming. so you add 0.5/g per gallon at this time.

then you add the second dose 0.5 grams per gallon at 1/3 dry . and none should be added after the 50% dry mark . this allows the yeast to have a steady fermentation curve.

adding all of your nitrogen at 1/3 creats a big spike of heat and activity , followed by a big crash and possibly a stuck ferment. you want an nice smooth linear fermentation curve.

nutirent added past the 50% mark , especialy inorganic nitorgen can't be metabolised by yeast . any nitrogen not consumed is left in the wine as food for spoilage organisims

following the lallmand instructions for the use of fermaid (laid out above) is the surest way of not having problems with your ferment.

as long as the ferment doesn't actualy get stuck ( no movement in drop of brix over 3 days) your best cource of action is just to stir it up ( all the yeast on the bottom, as well as punching down the cap) well and let it finnish , slowing down towards the end is pretty normal , the last 3 brix can take longer than the previous 10 .


lallmands instructions cut and pasted from their site

If Fermaid K complex yeast nutrient is used, the recommended dosage is as follows: ( NOT 1/3 and then 2/3 nor all of it at 1/3 )

Add 12.5 g/hL (1 lb/1000 gal) FERMAID® K at the end of the lag phase (beginning of alcoholic fermentation).

and


Add 12.5 g/hL (1 lb/1000 gal) FERMAID® K around 1/3 sugar depletion.

http://www.lallemandwine.us/products/nutrient_strains.php