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THE FOOD ARTICLE by John Daumé FERMENTATION NUTRIENTS: SUPER-SUPER FOOD: Super Food by itself is a blend of Yeast Hulls, DAP, Yeast Extract, Vitamins, Minerals. To this is added extra DAP and Vitamins.
Recommended dosage is 6 lbs/1000 gallons. or 1/2 oz/5 gallons. Add Super-Super Food for yeast growth in nutrient deficient
must and whenever adding M/L bacteria. The following is a re-cap of some really good advise from
The Wine Lab in Napa Valley by Lisa Van De Water called "Lessons
From Harvest 1996". Last year, surprises were the norm. Wave after wave of searing heat. Unripe fruit dehydrated on the vine. Green Chardonnay with soft seeds. Merlot with hard tannins. Both shriveling prematurely to 25+ Brix. Others were mature but sailed past optimal sugars. Then came a cool spell, but many vines had already shut down. Ripening came slowly and painfully. Potassium uptake climbed, acids dropped, pH's soared. Well that's what Tartaric Acid is for. With the high potassium, it falls out anyway, taming the pH in the process. However, reds not tested (esp. after soaking on skins) were sometimes left too high in pH during ferment, encouraging various spoilage mechanisms. In the Central Coast, bad heat spells meant lower grape nitrogens, and a lack of other nutrients as well. Certainly, stressed vines that cannot bring water up through their tissues cannot move nutrients into the grapes. This brought grapes that needed even more nutrient supplementation than normal. Severe vine stress, nutrient-deficient grapes, and unexpectedly high sugars spawned a record number of stuck fermentations. With fermentation is under stress, even a small increase in an inhibitory factor can tip the balance away from yeast survival. Musts that might have finished fermenting at slightly lower alcohols, or with a more vigorous yeast, or with greater nutrient supplementation, instead struggled until the combination of negative influences overcame them. Timing of M/L inoculation also becomes more critical.
Even the most benign Leuconostoc bacteria can compete with growing yeast
for nutrients and vitamins in a deficient must. Conversely, nutrient-hogging
yeast can deplete a must so thoroughly that M/L bacteria have no chance
until the yeasts die and release stored nutrients. If problems are expected,
it may be best to wait until after yeast fermentation to inoculate for
MLF. In a healthy fermentation by a vigorous byanus strain (Pries de Mouse/Premiere
Cuvee group), early inoculation, plus Super-Super Food, is usually preferable.
M/L Recommendations: M/L add at beginning of fermentation when:
M/L add after fermentation when:
Of course, 1996 had its share of opportunistic bacteria. In any year, no-SO2 red fermentations are always at high risk for attack by aggressive Lactobacilli from vineyard or winery. They make acetic acid from sugar, stopping yeast fermentation and killing M/L bacteria. Adding 30-35 ppm SO2 at crush prevents this dreadful spoilage, if SO2 is mixed throughout the must, and pH is reasonable (<3.6 after soaking overnight). But, when trying to restart a stuck yeast ferment, Lactobacilli
can become acclimated, encouraged by now-low SO2, warm temps, O2, and late-added
nutrients. All too frequently, reds stuck for other reasons subsequently
spoil from Lactobacilli while waiting to go dry. These comments from Lisa remind us:
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