A Method for the Consistent Estimation of Real Degree of Fermentation

Cutaia, Anthony J.; Munroe, J.

doi:10.1094/asbcj-37-0188

Cited by 6 publications

(5 citation statements)

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“…It can be measured a multitude of ways, but the most effective method given the resources is using near-infrared (NIR) detection on a density meter equipped with these capabilities [26]. Using this instrument, a researcher can accurately determine the real degree of fermentation (RDF), a direct correlation of the attenuation of a certain yeast taking into account variability in the gravity of the starting wort [27,28].…”

Section: Introductionmentioning

confidence: 99%

Dry-Hop Creep Potential of Various Saccharomyces Yeast Species and Strains

2021

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Previous research has shown that hops contain enzymes able to hydrolyze unfermentable dextrins into fermentable sugars when added during the dry-hopping process. In the presence of live yeast, these additional fermentable sugars can lead to an over-attenuation of the beer; a phenomenon known as “hop creep”. This study attempts to analyze the effect of different Saccharomyces yeast species and strains on hop creep, with the intent to find an ability to mitigate the effects of dry-hop creep by using a specific yeast. Thirty different yeast species and strains were chosen from commercial and academic collections and propagated for pilot fermentations. Brews were performed at the Anheuser-Busch Research Brewery (1.8 hL, 10 °P, 20 IBU) at UC Davis and split to 40 L cylindroconical fermenters, with one fermenter in each yeast pair receiving 10 g/L Centennial hop pellets towards the end of fermentation. Standard analytical measurements were performed over the course of fermentation, with real degrees of fermentation (RDF) and extract measured on an Anton Paar alcolyzer. In order to preemptively determine the amount of hop creep to be experienced with each unknown fermentation, bench-top fermentations with 20 g/L dry-hops were performed concurrently and compared to the pilot scale fermentations. RDF was significantly higher (p < 0.01) on dry-hopped than non-dry-hopped fermentations beginning two days post dry-hopping to the end of fermentation, with the exceptions of SafAle™ BE-134, a S. cerevisiae var. diastaticus, and UCDFST 11-510, a S. mikatae. No apparent correlation between flocculation and increased RDF was shown in dry-hopped treatments. pH was significantly different between the dry-hopped and non-hopped fermentations (p < 0.05 one day post dry-hop, p < 0.01 for all subsequent days); this may have impacted on additional attenuation. No yeasts in this study indicated their use for mitigation of dry-hop creep, but this is a first look at beer fermentation for some of the chosen yeasts. The results also present a new perspective on how hop creep varies in fermentation.

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Section: Introductionmentioning

confidence: 99%

Dry-Hop Creep Potential of Various Saccharomyces Yeast Species and Strains

2021

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“…The observed difference was reflected in the calculation of the degree of fermentation especially in the articles of American authors (Cutaia and Munroe, 1979). The relationship of Balling's alcohol factors to contemporary brewing has been addressed in our previous reports (Košin et al, 2013;Šavel et al, 2015).…”

Section: Introductionmentioning

confidence: 94%

Interpolation formulas for Balling´'s alcohol factors

Šavel

Košin

Brož

et al. 2020

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The article deals with the interpolation of the Balling alcohol factors, given at isolated points in 1% (m/m) increments ranging from 1 to 30% in the Hrach table published in 1927. Interpolation was necessery for the calculation of real (RDF) or apparent (ADF) degree of attenuation, according to which optimal barley varieties were selected for beer production. Analytica EBC initially preferred ADF, although it also reported RDF, used by ASBC. According to ASBC, the Balling RDF is multiplied by a correction factor or calculated using a modified calculation formula. Both ways gave the same results and increased Balling RDF values by 1-2% m/m. Refractometry with a pocket digital refractometer set to °Bx allows beer analysis from a minimum sample volume.

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“…which takes into account the amount of yeast and carbon dioxide removed during fermentation (Cutaia and Munroe, 1979). This correction is not necessary for fermentation in a closed container.…”

Section: Výpočtymentioning

confidence: 99%

“…V současnosti se používá skutečný stupeň prokvašení ve tvaru: 2,0665 A 6. RDF (EBC) = 100 -----------2,0665 A + n který bere v úvahu množství kvasnic a oxidu uhličitého, odstraněného během kvašení (Cutaia a Munroe, 1979). Při kvašení v uzavřené nádobce není tato korekce nutná.…”

Section: Effect Of Yeast Dose and Agitation On Pressure Growth Duringunclassified

Use of Laboratory Pressure Measurement for Fermentation Process Monitoring

Šavel¹,

Košin²,

Strejc³

et al. 2018

Kvasny Prum

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Laboratory pressure fermentation can be used for process monitoring such as measurement of yeast activity, its resistance to temperature, carbon dioxide, sanitation agents or determination of fermentation process yield. This method does not replace precise analytical methods but it can be used if they are economically or time demanding. This paper deals with the determination of fermentable sugars in brewing substrates, yeast activity kinetic measurement and rapid estimation of conditions influencing the fermentability determination. The advantages of pressure fermentation in a closed container are the elimination of volatile fermentation products escape including water vapor and the possibility of serial processing of large quantities of raw materials with simple equipment.

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A Method for the Consistent Estimation of Real Degree of Fermentation

Cited by 6 publications

References 0 publications

Dry-Hop Creep Potential of Various Saccharomyces Yeast Species and Strains

Dry-Hop Creep Potential of Various Saccharomyces Yeast Species and Strains

Interpolation formulas for Balling´'s alcohol factors

Use of Laboratory Pressure Measurement for Fermentation Process Monitoring

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