A little green mold in primary

From the descriptions, the nutrient is DAP and the energizer is predominantly, if not completely, yeast hulls.

FWIW, one teaspoon of DAP is approximately 4.0 grams and one teaspoon of the energizer is very likely around 2.75 grams (based on my yeast hulls assumption). So with one teaspoon of each, you haven't added very much nutrient at all.

Earthson said:

Ok, so how much should I be adding to the stalled mead? And how much to a new mead? ??? My brain hurts from all the learning :icon_scratch:

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Sorry, the calculations of how much nutrient to add are some of the most confusing in meadmaking - I can understand your problem.

Generally speaking, any mead or wine-strength fermentation can benefit from the addition of nutrients, especially yeast assimilable nitrogen, or YAN. Unfortunately given that you used the Wyeast Sweet Mead yeast in here, nutrients may not be sufficient to keep things going. You should strive for a target value of at least 225 ppm YAN (some from fruit if you use fruit in your recipe, and the rest from nutrient additions), and even more if the initial gravity is high or if the yeast strain that you use is a high nitrogen demand yeast.

I will get back to this later today and give you some specific recommendations for your batches (since I'm actually on travel this week and I've got to log off and get to "real work" shortly) although with a stuck batch it is often too late to get things fired up again simply from a nutrient addition. If someone like Medsen or Oskaar want to jump in here and provide you with more details in the interim, that would be fine, too! ;D

From looking at those nutrients, I'd probably add another 3 tsp of the nutrient and an additional 2 tsp of the energizer if the gravity is still above about 1.050. Beyond that point the nutrients may not be much help.

The pH may also be a problem here.

Thanks for stepping in with some dosing advice, Medsen! My apologies for not getting back sooner -- we worked until midnight last night and I was in no mood to fire up the laptop when I got back to my room.

Earthson, even though EC-1118 is a brute, you should follow re-start protocol and acclimate your yeast by adding a little of the already in-process must after you rehydrate the yeast and before you pitch it into the main batch. The idea is to gradually get the yeast used to the slightly alcoholic environment of the must rather than shocking them by hitting them with the full impact all at once. You're probably not far enough along to require a multiple succession of incremental additions. If you just add an amount of must equal to what you have of yeast slurry to the rehydrated yeast, then let that mixture set until you see signs of fermentation, then pitch, that should work for you.

Once you then see signs of activity in the main batch, add the nutrients as Medsen suggested.