仙人掌果精酿啤酒发酵工艺及其品质分析

以仙人掌果、大麦芽、酒花等为原料,开发仙人掌果精酿啤酒。采用单因素试验探讨仙人掌果汁添加量、原麦汁浓度、酒花添加量对仙人掌果精酿啤酒感官评价的影响,应用正交试验确定发酵工艺,并对其品质分析。结果表明,发酵过程中各因素对感官评价的影响大小为:仙人掌果汁添加量酒花添加量原麦汁浓度;最佳发酵工艺为:仙人掌果汁添加量5%、原麦汁浓度12°P、酒花添加量为0.20%。此工艺制得仙人掌果精酿啤酒的感官综合得分为92.6分,其理化指标和卫生指标均符合国家标准,是一款独具特色的精酿啤酒。本研究结果为仙人掌果精酿啤酒的工业化生产提供技术支撑。     

响应面法优化帝国世涛啤酒酿造工艺的研究

以感官评分为主要评价指标,通过单因素和响应面试验,对帝国世涛啤酒酿造工艺参数（原麦汁浓度、发酵温度、白砂糖添加量）进行优化。结果表明,原麦汁浓度对帝国世涛啤酒品质的影响最大;帝国世涛啤酒的最佳工艺参数为：原麦汁浓度16 °P,发酵温度21 ℃,白砂糖添加量5.1%。在此最佳工艺条件下,帝国世涛啤酒的感官评分为95分,各项理化指标均符合啤酒国家标准;所酿造的帝国世涛啤酒呈现浓黑色,泡沫绵密而扎实,复合香气协调浓郁,酒体厚重,余味绵长,同时具有很强的包容性。     

低浓度啤酒酿造法

最近,麒麟啤酒公司发表特许公告“啤酒的酿造法”。该发明是采用特别提高啤酒发酵度的方法生产低浓度啤酒。取用原麦汁浓度为14～19°P的发酵高泡期的发酵液,当糖度降至原麦汁浓度的40～50%时,抽取麦汁发酵液与酒花提取液混合,再与原麦汗浓度为6—9°P的发酵     

干啤洒的研究

<正>干啤酒一般采用10%左右的原麦汁浓度;实际发酵度在75%左右,糖化时通常使用淀粉辅料和糖浆,发酵是使用高发酵度酵母菌种和     

酵母菌株对低浓度啤酒酿造的影响

啤酒酵母BY - 1,BY - 2 ,BY - 3和BY - 4分别接入 6°P、7°P、8°P麦汁中 ,10℃发酵。监控发酵过程中的酸度、pH值、酒精度 ,并对过滤啤酒进行感官品评。相同麦汁浓度下 ,4株酵母的发酵液酸度、pH、酒精度值无较大差异。发酵后 6°P麦汁pH值下降约 1.5 ,7°P、8°P麦汁下降约 1.2。发酵 6°P、7°P和 8°P麦汁时 ,BY - 2酵母所酿啤酒风味最佳。     

发酵度对7°P啤酒酿造的影响

低浓啤酒以其口味干净爽口、酒花香味明显、酒精少、热量低、营养丰富等特点越来越受到消费者的欢迎.该研究用7°P定型麦汁,采用下面发酵法酿造4种成品啤酒(发酵度分别为57.6%、63.4%、67.9%、72.5%).在相同条件下,进行发酵试验并跟踪主发酵过程总酸、pH、α-氨基酸、酒精度、还原糖与真正浓度的变化.发酵延滞期均为1d,总酸先降后升,pH、α-氨基酸、还原糖与真正浓度逐渐降低,酒精度逐渐升高.成品酒中α-氨基酸残留量随发酵度升高而增加,为麦汁的12.3%～19.4%;pH下降1.79～1.89;总酸、还原糖含量随发酵度升高而增加,分别为0.62～0.77mL/100mL、0.1mol/LNaOH与3.2～4.80g/L.浊度随发酵度的增加而降低,色度变化不大.感官品尝显示发酵度为57.6%时,7°P啤酒风味最佳.     

石榴精酿啤酒酿造工艺优化的研究

以石榴和大麦芽为主要原料,对石榴精酿啤酒进行发酵工艺优化。通过单因素试验研究原麦汁浓度、石榴汁添加量、石榴汁添加时间对石榴精酿啤酒品质的影响,以响应面法进行优化设计,以感官评分为响应值,进行发酵工艺优化。最佳发酵工艺为:原麦汁浓度为11.2 °P、石榴汁添加量为11.3%、石榴汁添加时间为主发酵第5天,在此条件下进行100 L发酵罐放大试验,获得了一款外观呈宝石红色,泡沫洁白细腻,口味纯正,酸甜爽口,有明显酒花香气的精酿啤酒。     

发酵工艺参数对嫩啤酒抗氧化力的影响

为提高啤酒的抗氧化力及改善其风味稳定性,系统研究了麦汁发酵过程中抗氧化力的变化及发酵工艺参数包括麦汁浓度、酵母接种量、酵母代数与发酵温度对嫩啤酒抗氧化力的影响。结果表明:麦汁发酵过程中DPPH自由基清除活性、氧自由基吸收能力和还原力分别提高了6.27%、3.46%和31.38%。麦汁浓度从6°P增加到12°P,嫩啤酒的DPPH自由基清除活性、氧自由基吸收能力与还原力升高显著,浓度超过12°P后,抗氧化指标增速减缓或略有下降。酵母接种量在800～3200万个/mL之间的嫩啤酒抗氧化力随酵母接种量的增加而升高。1、2、4和5代酵母发酵嫩啤酒的抗氧化力随酵母代数的增加呈降低趋势。9、12和15℃发酵嫩啤酒的抗氧化力随发酵温度的升高而降低。因此,优化发酵工艺参数是提高啤酒抗氧化力的有效措施。     

蜂蜜艾尔精酿啤酒酿造工艺研究

以澳洲淡色艾尔大麦芽、澳洲水晶焦香麦芽、酒花和蜂蜜为原料,选用上面发酵的WB06型艾尔酵母进行发酵,酿制蜂蜜艾尔 精酿啤酒。以感官评分为评价指标,通过单因素试验和响应面试验研究了原麦汁浓度、发酵温度、葡萄糖添加量及蜂蜜添加量对蜂蜜 艾尔精酿啤酒感官品质的影响。结果显示,蜂蜜艾尔精酿啤酒的最佳酿造工艺条件为：原麦汁浓度12.56 °P,发酵温度18 ℃,葡萄糖添 加量7 g/L,蜂蜜添加量3.05%。 采用该工艺条件酿造的蜂蜜艾尔精酿啤酒产品,各项指标符合GB/T 4927—2008《啤酒》中特种啤酒质 量要求,啤酒的感官评分为96.64分,酒体呈琥珀色,泡沫丰富细腻,挂杯持久,麦香、酒花、蜂蜜香气协调,口感细腻,酒体饱满。     

上面酵母酿造特性的研究

采用4株上面发酵酵母酿造几批同等浓度(12°P)的啤酒,待起发后每天取样测定外观发酵度、真正发酵度、酒精度、双乙酰含量,绘制降糖曲线,然后利用高效液相色谱检测啤酒风味物质4-乙烯基愈创木酚含量。再利用全自动分析仪测定啤酒理化指标,结合感官品评,证明4株上面发酵酵母酿造特性良好。     

不同原浓啤酒中有机酸的含量分析

以相同原料配比,用下面发酵法酿造6 0、6 5、7 0、7 5、8 0与10 0°P啤酒。样品总酸随原浓上升而提高,原浓低于7 5°P时,啤酒酸味明显。用反相高效液相色谱(RP -HPLC)法在啤酒中检测出了10种有机酸:草酸、酒石酸、丙酮酸、苹果酸、α酮戊二酸、乳酸、乙酸、柠檬酸、富马酸与琥珀酸,总量为738 17～799 5 0mg/L ,各样品间有机酸含量差异明显。琥珀酸含量最高;其次是柠檬酸、苹果酸、丙酮酸、乳酸与草酸。草酸、丙酮酸随着原浓的增加而升高。7 0、7 5、8 0、10 0°P啤酒中乳酸含量相近,6 0、6 5°P啤酒中乳酸含量急剧上升。研究结果表明,啤酒酵母产酸受原浓与发酵度的影响     

Biological acidification and beer quality: addition of lactic acid bacteria isolated from malt

Two lactic acid bacteria, Pediococcus acidilactici HW01 and Leuconostoc citreum isolated from Pilsner malt, were added during mashing and the impact on fermentation examined. The pH of lactic acid bacteria supplemented (bioacidified) wort and finished beer were lower than that of the control. Bioacidified worts resulted in higher levels of free amino nitrogen, reducing sugars and alcohol in the corresponding beers. Foam stability of beers from P. acidilactici and L. citreum worts were increased by 19% and 26%, respectively. The filtration time was reduced in P. acidilactici treated beers but increased with L. citreum. The use of P. acidilactici and L. citreum as bioacidification agents resulted in beers with higher sensory quality. © 2020 The Institute of Brewing & Distilling     

Yeast Proteolytic Activity During High and Low Gravity Wort Fermentations and its Effect on Head Retention

The aim was to discover the effect of high gravity brewing on yeast protease activity during fermentation, on the loss of hydrophobic polypeptides from wort during fermentation, and on the foam stability of stored beer. The hydrophobic polypeptide content of low (10° Plato) gravity worts showed a steady decline throughout fermentation, but for the 20° Plato wort there was a rapid decline over the first 8 days of fermentation, followed by little change over the remaining period. The decrease in hydrophobic polypeptides was greater in the high gravity fermentation. Proteinase A increased during fermentations with the highest levels being present at the end of fermentations. High gravity fermentations exhibited levels of yeast protease that from the 3rd to 11th day of fermentation were at least twice the values of the low gravity fermentations. The high gravity brewed beer contained significantly higher levels of proteinase A activity than the low gravity brewed beer. The inclusion of FERMCAP™, an antifoam, in high gravity wort did not affect either the hydrophobic polypeptide levels or foam stability of the resultant beer. This suggests that proteinase A, rather than fermenter foaming, must be the major contributor to the lack of foam stability of high gravity brewed beer. Head retention measurements conducted on the high and low gravity brewed bottled beers, over a five month period, demonstrated a steady decline in foam stability for both beers. The declines in head retention did not occur in high and low gravity beers that had been pasteurised.     

Pilot Scale Production of a Lager Beer from a Grist Containing 50% Unmalted Sorghum

Pilot scale (1000 L) brews were carried out with a grist comprising of unmalted sorghum (50% of total wet weight of grain) (South African variety) and malted barley (50% of total wet weight of grain) grist using a mashing program with rests at 50°C, 95°C and 60°C. Mashes were supplemented with a high heat stable bacterial α‐amylase, a bacterial neutral protease and a fungal α‐amylase. A control brew containing 100% malted barley was also carried out. Saccharification difficulties were encountered during mashing, and extraction of the grist was lower for the sorghum mashes. The sorghum mashes showed comparable lautering behaviour to that of the control mash. At mashing off the sorghum worts were starch positive. Apparent degree of fermentation of the sorghum gyles were less than the control gyles. Green beer filtration proved unproblematic. The sorghum beers compared quite closely with the control beer with regard to colour, pH and colloidal stability. Foam stability deficiencies were apparent with the sorghum beer. However, the fermentability of the sorghum worts were lower. Hence the sorghum beers were lower in total alcohol. Sensory analysis indicated that no significant differences existed between the sorghum beer and both the control beer and a commercial malted barley beer with regard to aroma, mouth‐feel, after‐taste and clarity. However, the sorghum beer was found to be significantly different to both of the other beers with regard to colour, initial taste and foam stability.     

高浓酿造法生产高辅料啤酒的研究

该文通过试验研究,确定了75%高辅料的糖化工艺、麦汁16°P高浓度的发酵工艺、高浓稀释工艺。采用上述工艺不仅生产的产品质量达到GB4927标准,而且感官指标和风味都比较稳定。从而提高了现有设备的利用率,增加了产量,降低了成本,提高了企业的经济效益。     

High Gravity Brewing by Continuous Process Using Immobilised Yeast: Effect of Wort Original Gravity on Fermentation Performance

The present work evaluated the influence of all‐malt wort original gravity on fermentative parameters and flavour‐active compound formation during primary fermentation of high gravity brewing by a continuous process using a lager yeast immobilised on a natural carrier obtained from brewer's spent grain (the main brewery by‐product). The all‐malt worts with original gravity (OG) ranging from 13.4 to 18.5°Plato were prepared by diluting a very‐high‐gravity wort (20°Plato) with sterile brewery water. The continuous assay was carried out in a bubble column bioreactor with a total working volume of 5.2 litres, at 15°C, using a constant gas flow rate of 250 mL/min (200 mL/min of CO₂ and 50 mL/min of air) and a dilution rate of 0.04 h^?1 (residence time of 25 h). The results indicated that as the wort OG was increased, the ethanol concentration of the outflowing beer increased. On the other hand, the continuous fermentation of the most concentrated worts (16.6 and 18.5°Plato) resulted in beers with unbalanced flavour profiles due to excessive ethyl acetate formation. The immobilised cell concentration appeared to be nearly independent from increasing wort OG.     

Indian black rice: A brewing raw material with novel functionality

Indian black rice (Chakhao Poireiton) is a pigmented variety, rich in anthocyanins and other phytonutrients. With growing interest in the use of local raw materials in brewing, it was of interest to develop protocols for malting and brewing with Chakhao Poireiton to see whether the antioxidant capacity of anthocyanins could be delivered into finished beer. Protocols for brewing with 100% malted rice were developed and the performance of Indian black rice compared with that of an Italian white rice cultivar suited to brewing. The apparent fermentabilities of rice worts were 69.5% (black) and 67.3% (white), yielding beers of 3.28 and 3.19% ABV respectively. Black rice worts were deficient in free amino nitrogen (83.5 mg/L relative to 137 mg/L for white rice) and would need nitrogen supplementation to avoid issues with fermentation, e.g. elevated diacetyl. Black rice beer had an orange-red hue as a result of extraction of anthocyanin pigments (2.84 mg/L). The oxidative stability of 100% rice beers was measured using electron spin resonance spectroscopy and both samples were found to be unusually stable. Interestingly, when rice beers were blended with a control barley malt derived lager in varying proportions (10, 25, 50%), the oxidative stability was improved, relative to the control lager, particularly so in the case of black rice beer, which contained an antioxidant capacity over and above that of the white rice beer. Future studies are required to determine whether the noted oxidative stability of 100% rice malt beers results in a more flavour-stable beer. © 2019 The Institute of Brewing & Distilling     

pH Induced Aggregation and Weak Gel Formation of Whey Protein Polymers

Whey protein polymers were formed by heating (80 °C) a 4% (w/v) whey protein (WP) isolate dispersion at pH 8.0 for 15, 25, 35, 45, or 53 min. Dispersions were adjusted to pH 6.0, 6.5, 7.0, 7.5, or 8.0 after heating and the rheological properties were determined. Viscosity increased with increased heating time and decreased pH. At pH 7.0 and 7.5, high-viscosity dispersions with pseudoplastic and thixotropic flow behavior were formed, while weak gels were formed at pH 6.0 and 6.5. The storage (elastic) and loss (viscous) moduli of pH-induced gels increased when temperature was increased from 7 °C to 25 °C, suggesting that hydrophobic forces are responsible for gelation. Key Words: weak-gels, whey proteins, polymers, gelation, functionality     

Roasting of malt and xanthohumol enrichment in beer

The use of commercial roasted malts increases the content of the hop polyphenol xanthohumol (XN) in beer. This carrier effect is caused by high molecular melanoidins from roasted malt. Three roasting trials with different malts were performed in order to study the development of XN enrichment of wort and beer in laboratory and brewing trials. Different colour measurements, malt and flavour analysis, radical formation and antioxidative activity of selected samples were carried out. Furthermore, sensory tests of beers were conducted. During roasting the XN and isoxanthohumol enrichment in wort and beer rose with the roasting intensity of malt until it reached a maximum. The XN content in wort increased linearly with the colour of wort made from the malt samples. In PVPP-treated worts and in filtered beers, the XN content increased exponentially with the colour. After passing through a maximum, both the colour value and XN content in wort and beer decreased. Interestingly, the colour losses were more intensive than the losses of XN in worts and beers. The development of radical formation and the reducing power was linked during roasting. That means reducing groups of melanoidins are responsible for reducing power and prooxidative properties of malts. These functional groups of melanoidins are involved in the development of XN enrichment properties, because a linear correlation between these parameters was found. In conclusion, the roasting regimes showed potential for the development of special malt for the XN enrichment in beer- or malt-based beverages in late roasting stages. The use of this special malt brings more XN with less coloured malt in beer.