D47 Nutrient Demands
Posted 02 September 2010 - 09:12 AM
Everything I've read about D47 says that it has low nutrient demands and it produces little H2S. Since I'm working with desert grown grapes and the soil around here is marginal, it could be that my grapes are exceptionally low in nitrogen or something else the yeast needs.
I've tried several different combinations of nutrients, and I've experimented with adding nutrients at various times during fermentation, but still, this H2S problem occurs every few batches. Since the H2S shows up later in the fermentation, I'm thinking about starting out with D47, but as the SG drops to 1.040, pitching a healthy starter of EC-1118.
So, does anyone have nutrient recommendations to make and what do you think about my idea of finishing with EC-1118?
Posted 02 September 2010 - 09:34 AM
D47 is used frequently with meads, and usually doesn't get too stinky even when the nutrients are sparse, however, it does happen sometimes. Although it is reported to have low nutrient requirements, I find that ensuring it 200 ppm YAN and all the micronutrients normally keeps it happy. I usually accomplish this with 2/3 from Fermaid K, and 1/3 from DAP.
Toward the end of Fermentation if it gets smelly, I usually treat with some Fermaid 2133 and/or some yeast hulls (1 g per gallon), and that has always corrected the issue for me when H2S has developed with D47.
Temp control and pH may also be factors. I've had more issue with H2S at high temps and really low pH. I don't know if that could be a factor with your musts.
(Past years are always better)
Posted 02 September 2010 - 11:54 AM
It worked better in my two carboys of Cayuga, although I think one of those has a trace of sulfide as its finishing up.
pH may be an issue in my case. My Traminette was 3.1, the Cayuga was higher at 3.34 but I'd added a little acid blend so it might be slightly lower.
Secondary: Concord, Cayuga, Traminette, Norton, Chambourcin
Barreled: WE SI Brunello, Dornfelder, Sangiovese/Merlot 3:1
Posted 02 September 2010 - 09:57 PM
In Vino Veritas
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