Method for evaluating quality stability of beer

Abstract

The invention discloses a beer quality stability evaluation method, and relates to the technical field of beer quality evaluation. Comprising the following steps: (1) detecting a beer sample before fermentation; (2) re-fermenting the beer sample; (3) detecting the beer sample after fermentation; and (4) comparing delta F of different batches of beer. The method provided by the invention needs a small amount of samples, does not need to be evaluated by professionals, and can evaluate the quality stability of beer through physical and chemical indexes within 48 hours, thereby evaluating the rationality of a beer process and making corresponding adjustments to production.

Description

Technical Field

[0001] The invention relates to the technical field of beer quality evaluation, and more particularly to a method for evaluating beer quality stability. Background Art

[0002] With its unique charm, beer has become one of the most popular alcoholic beverages in the world. The process is mainly the process of yeast converting fermentable sugars in wort into alcohol and carbon dioxide, while giving beer a unique flavor and aroma. However, due to different strains and qualities, the thoroughness of the utilization of fermentable sugars in different brands and batches of beer is different, so the fermentation stability between each batch is different. The stability of fermentation directly affects the refreshing and mellow taste of different batches of beer; the stability and thoroughness of fermentation are ultimately reflected in the apparent properties of beer, such as alcohol content, residual sugar content and other indicators. These indicators can reflect the stability and thoroughness of fermentation, thereby indirectly evaluating the factors affecting the taste. At present, the study of the impact of beer stability on taste is the main direction of beer stability research. However, there is a shortage of methods for evaluating the fermentation stability of a beer production process, and there is no simple and fast method to evaluate the stability of beer quality.

[0003] Therefore, it is an urgent problem for technical personnel in this field to establish a method for evaluating the fermentation stability of beer based on the quality and physical and chemical analysis of beer, which can quickly analyze the raw material utilization of beer and evaluate the stability and thoroughness of quality. Summary of the invention

[0004] In view of this, the present invention provides a method for evaluating the stability of beer quality.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for evaluating beer quality stability comprises the following steps:

[0007] (1) Detection of beer samples before fermentation: Sample the beer to be tested, detect its alcohol content and true concentration after degassing, and calculate the true fermentation degree F1 through the beer fermentation degree detection method;

[0008] (2) Re-fermentation of beer samples: Using brewer's yeast to re-ferment the same batch of beer in a clamp bottle under controlled temperature to obtain fermented beer samples;

[0009] (3) Post-fermentation testing of beer samples: centrifuge the fermented beer to obtain the beer supernatant, degas it again, test its alcohol content and true concentration, calculate the true fermentation degree F2, and calculate the difference ΔF between it and the true fermentation degree F1 of the beer sample, i.e., F2-F1;

[0010] (4) Comparison of ΔF of different batches of beer: Perform steps (1) to (3) on different batches of beer to obtain ΔF of different batches, which are marked as ΔFa and ΔFb, respectively, and compare the absolute values ​​of the differences between ΔFa and ΔFb;

[0011] If |ΔFa-ΔFb|≤0.15, the quality can be considered very stable;

[0012] If 0.15<|ΔFa-ΔFb|≤0.5, the quality can be considered to be relatively stable;

[0013] If |ΔFa-ΔFb|>0.5, it can be considered that the quality is unstable.

[0014] Furthermore, the sampling in step (1) is: sampling 300 mL in a clean bench.

[0015] Furthermore, the method for detecting the true fermentation degree of beer in step (1) is the national standard for beer (GB / T 4928-2008): 13 true (actual) fermentation degree.

[0016] Furthermore, the brewer's yeast in step (2) is active dry yeast, and the added amount is 0.5 g to 1 g per 200 mL of beer;

[0017] Furthermore, the volume of the clamp bottle in step (2) is 100mL-1000mL, and it is airtight and leak-free.

[0018] Furthermore, the temperature of step (2) is controlled at 20°C-30°C, and the re-fermentation time is 24h-48h.

[0019] Furthermore, in step (3), the centrifugal speed is 4000 rpm-7000 rpm, the centrifugal time is 5 min-10 min, and the temperature is 5°C-20°C.

[0020] It can be seen from the above technical solution that, compared with the prior art, the beneficial effects of the present invention are:

[0021] The present invention requires a small amount of sample and does not require professional evaluation. The quality stability of beer can be evaluated through physical and chemical indicators within 48 hours. If the actual fermentation degree of the beer sample after re-fermentation is significantly different from the original, it proves that its quality is not stable enough, and the rationality of the beer process can be evaluated to make corresponding adjustments to the production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 The accompanying drawing is a schematic diagram of the beer detection process of different batches of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Examples Source of materials:

[0026] Beer Samples:

[0027] The brewing center brews beer by itself, taking six different numbered beers, numbered 1-6, and the brewing location is the Chinese Institute of Food Fermentation Industry, No. 24, Jiuxianqiao Middle Road, Chaoyang District, Beijing;

[0028] Saccharomyces cerevisiae: active dry yeast, purchased from SafLager W-34 / 70 strain of Lesaffre brand in France, origin: Belgium; manufacturer: Fermentis Yeast Co., Ltd.; batch number: 2201222.

[0029] Example 1

[0030] (1) Beer sample pre-fermentation testing: Beers 1-6 were sampled from the brewing center, 300 mL of which were sampled from the clean bench. After degassing, the alcohol content and true concentration were measured, as shown in Table 1, and the true fermentation degree F1 was calculated;

[0031] (2) Re-fermentation of beer samples: 200 mL of degassed beer was transferred to a clamp bottle, 0.50 g of active dry yeast (Saccharomyces cerevisiae) was added, and the mixture was fermented at 20°C for 24 h to obtain a re-fermented beer sample;

[0032] (3) Post-fermentation testing of beer samples: The fermented beer is centrifuged at a controlled temperature and degassed again to test its alcohol content and true concentration. The true fermentation degree F2 is calculated, and the difference ΔF between the true fermentation degree F1 of the beer sample and the true fermentation degree F2 is calculated, i.e., F2-F1, as shown in Table 1;

[0033] (4) Comparison of ΔF of different batches of beer: Perform the same operation process from step (1) to (3) on the two batches of beer 1-6 to obtain the ΔF of the two batches of beer 1-6, i.e., ΔF a , ΔF b Etc., compared with ΔF a , ΔF b , the results are shown in Table 1.

[0034] Table 1 Example 1 Beer quality stability evaluation table

[0035]

[0036] The results in Table 1 show that the |ΔF a -ΔF b |=0.23<0.5, it is considered that its quality is relatively stable; |ΔF of beer 2 a -ΔF b |=1.59>0.5, the quality is considered unstable; |ΔF of beer 3 a -ΔF b | = 0.03 < 0.15, the quality is considered to be very stable; |ΔF of beer 4 a -ΔF b |=0.54>0.5, the quality is considered unstable; |ΔF of beer 5 a -ΔF b |=0.11<0.15, the quality is considered to be very stable; |ΔF of beer 6 a -ΔF b |=0.1<0.15 is considered to have very stable quality.

[0037] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evaluating beer quality stability, characterized in that: The following steps are involved: (1) Detection of beer samples before fermentation: Sample the beer to be tested, detect its alcohol content and true concentration after degassing, and calculate the true fermentation degree F1 through the beer fermentation degree detection method; (2) Re-fermentation of beer samples: Using brewer's yeast to re-ferment the same batch of beer in a clamp bottle under controlled temperature to obtain fermented beer samples; (3) Post-fermentation testing of beer samples: centrifuge the fermented beer to obtain the beer supernatant, degas it again, test its alcohol content and true concentration, calculate the true fermentation degree F2, and calculate the difference ΔF between it and the true fermentation degree F1 of the beer sample, i.e., F2-F1; (4) Comparison of ΔF of different batches of beer: Perform steps (1) to (3) on different batches of beer to obtain ΔF of different batches, which are marked as ΔF. a , ΔF b , compared with ΔF a , ΔF b The absolute value of the difference; If |ΔF a -ΔF b |≤0.15, the quality can be considered very stable; If 0.15<|ΔF a -ΔF b |≤0.5, the quality can be considered to be relatively stable; If |ΔF a -ΔF b |>0.5, the quality can be considered unstable.

2. A method for evaluating beer quality stability according to claim 1, characterized in that: The sampling in step (1) is as follows: sampling 300 mL in a clean bench.

3. The method for evaluating beer quality stability according to claim 1, characterized in that: The method for detecting the true fermentation degree of beer in step (1) is the national standard for beer (GB / T 4928-2008): 13 true (actual) fermentation degree.

4. The method for evaluating beer quality stability according to claim 1, characterized in that: The brewer's yeast in step (2) is active dry yeast, and the added amount is 0.5g-1g per 200mL of beer.

5. The method for evaluating beer quality stability according to claim 1, characterized in that: The volume of the clamp bottle in step (2) is 100mL-1000mL and it is airtight and leak-free.

6. The method for evaluating beer quality stability according to claim 1, characterized in that: The temperature of step (2) is controlled at 20°C-30°C, and the re-fermentation time is 24h-48h.

7. The method for evaluating beer quality stability according to claim 1, characterized in that: In step (3), the centrifugal speed is 4000rpm-7000rpm, the centrifugal time is 5min-10min, and the temperature is 5℃-20℃.

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