The purpose of this page is to collect a variety of journals and research work that is relevant to the detailed understanding of yeast health, nitrogen uptake, enzyme effects, and fermentation both in general and in specific to honey or fruit. Please only add journals that do not require log in credentials and to your best knowledge are not pirated in any way. Also, please include a brief description of the content covered and format additions in the same was as the others to keep legibility of the wiki page.
TODO: These need to be organized somehow
A dense study on nitrogen uptake, both organic and inorganic.
Key conclusions are that inorganic nitrogen promotes a lag time of only hours as do specific organic nitrogen sources, while some organic nitrogen sources take as long as 32 hours. The amount of nitrogen in the must failed to correlate with the rate or the efficiency of nitrogen utilization but does effect the total ethanol production with more nitrogen producing more ethanol.
A study on the production of methanol in grape wine with the intent to influence the removal of some sample analyses requirements for wineries.
Concludes that there is more methanol red wines than white due to the increased time on the skins for red wines due to natural pectinase
- A study on the production of methanol and ethanol yield in fruit wine due to pectinase.
- Concludes R. coreanus juice ethanol yield by pectinase treatment was increased by 8.60% without exceeding US limits for methanol in wine, although exceeding some methanol limits in other countries in both the control groups as well as the groups with added pectinase.
- A paper on aromatics and their links with fusel alcohols in relation to yeast flavor profiles to promote the metabolic engineering of yeast strains for the production of individual Ehrlich pathway products.
- Concludes little on it's own as it is more of a summary of sources than any experiment. States that many yeast specific flavor compounds are the result of both stress and specific nitrogen sources.
- Mead focused study on a low ABV DAP fed fermentation using QA23 and D47 with varied micronutrients
- Concludes that micronutrients reduce lag phase by up to 24 hours in the samples but did not have a significant effect on the overall time to final gravity.
- A study that added chili peppers and cloves to a 14% must with ~200 YAN or less provided by bee pollen and analysed fermentation with infrared measurements.
- 28g/gal of cloves were able to significantly impair fermentation rate and increase lag phase, and 18g/gal of chili were able to slightly boost fermentation rate to control. A combination of both resulted in a slightly slower ferment than the chili or control but not nearly as drastic as a negative impact as the clove. The experimental methods appeared to be a reasonable way to measure fermentation rate and mead health with further study.
- Notes: Figure 3 has a serious typo in the tittle block swapping fermentation 2 and 3. YAN is arguably a touch low for the fermentation and the chilies may be imparting some YAN. Both adjuncts were added in levels that are too high to be intended for consumption, with the clove being exceptionally excessive.
- A study where a ~11% potential must was supplemented with 267 YAN from DAP for two cultures with two cultures left for control. Overpitched D47 and QA23 were added to one of each culture. Fermentation rate was recorded and volatilizes were measured post ferment.
- Concludes that both musts fermented 60% faster with DAP. Acetaldehyde production increased with with DAP but was strain dependent with QA23 producing more than D47. Control QA23 produced the most esters. Fatty acid production was increased with DAP use, but all concentrations were below the threshold for human perception. The author notes that excessive YAN is known to cause increased medium‐chain fatty acids (The YAN nutrient calculator targets 187 YAN for 11% ABV). The only aromatic phenol that was at human thresholds was ethyl octanoate, which has a fruity and sweet taste, with the DAP supplemented musts having 3-4 times the control must, and 10 times the detection threshold.
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- A study where high ABV meads were sampled both dry and sweet. Aroma, sweetness, alcohol expression and general appreciation were compared.
- Concludes that higher residual sugars contribute well to aroma, sweetness and general appreciation. Alcohol expression was not significantly influenced (p>0.05) by ABV when ABV was artificially raised by brandy addition although small trends could be seen variation due to testing method put them under the limit for statistical significance. No gender distinctions for sweetness were observed.