Distilled Spirits Methods

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

*A subset of methods in this chapter were designated as applicable. Refer to the Applicability Reference Guide for those methods determined to be not of use, not applicable, or in need of further testing.*

Glossary

View Glossary

Beer 2. Specific Gravity

Specific gravity is the ratio of the density of a substance to that of a standard substance. This method determines the specific gravity of beer with a digital density meter.

View MethodView Demonstration Video

Beer 3. Apparent Extract

Apparent extract is a measure of the solids dissolved in a fermenting liquid without correction for ethanol content. This method reports apparent extract, % by wt, to two decimal places.

View MethodView Demonstration Video

Beer 4. Alcohol

This method measures beer and distillate volumetrically and gravimetrically, determines alcohol refractometrically, determines ethanol by gas chromatography, alcohol and original gravity by an instrumental method, low alcohol concentrations by an enzymatic method, and alcohol and original extract content by using a relationship of absorbance at near-infrared wavelengths.

Calculator: Beer and Distillate Measured Gravimetrically

View Method

Beer 5. Real Extract

From the residue in the distilling flask after determination of alcohol (Beer-4), this method determines real extract by the method corresponding to the one used for alcohol determination.

Calculator: Beer Measured Volumetrically

View Method

Beer 6. Calculated Values

This method calculates values for extract of original wort, real degree of fermentation, apparent degree of fermentation, and the carbohydrate content of beer.

Calculators:

• Extract of Original Wort
• Real Degree of Fermentation
• Apparent Degree of Fermentation
• Carbohydrate Content of Beer

View Method

Beer 8. Total Acidity as 'Titratable Acidity'

Total acidity (TA) is defined as the number of acidic protons that the organic acid potentially can donate. It is experimentally determined by measuring the amount of sodium hydroxide required to raise the pH to 8.2, where neutralization of the acids occurs. Note, however, that using this method will not dissociate all of the protons and thus the method is more accurately defined as titratable acidity, which is the measurement of hydrogen ions consumed by titration with a standard base to an end point. Although technically different, titratable acidity is often used as an approximation of total acidity, and thus is generally referred to as TA.

View MethodMaster the MethodView Demonstration Video

Beer 9. pH (Hydrogen Ion Concentration)

This method reports the pH of beer to the nearest 0.1.

View MethodMaster the MethodView Demonstration Video

Beer 10. Color

Beer color is an essential component of the overall sensory perception of the product. Color is experimentally obtained by using a spectrophotomer to determine the absorbance or transmittance of the sample. This method determines the color of beer by the spectrophotometric color method, the photometric method, and tristimulus analysis.

Calculators:

• Spectrophotometric Color Method
• Tristimulus Analyisis Calculator (Excel)

View Method

Beer 11. Protein

Beer proteins are partially responsible for good foam retention and desirable mouth-feel characteristics, but they are also partially responsible for haze and undesirable bitterness in beer. This method determines the protein content of beer (% by weight) by the Kjeldahl method, by combustion, and by spectrophotometer.

Calculator: Report Protein in Beer

View Method

Beer 12. Reducing Sugars (Copper Reducing Substances)

This method determines reducing sugars in beer by the Munson and Walker method and by the Lane-Eynon volumetric method.

View Method

Beer 14. Ash 1958

Ash is the beer residue following the incineration of the organic matter. It consists of mineral matter and serves as a measure of the inorganic salts present in the beer prior to incineration. The ash value is a required term in the calculation of the nutritional components calories and carbohydrates. This method reports ash, % by wt, to two decimal places.

Calculator: Percent Ash in Beer

View Method

Beer 16. End Fermentation (Yeast Fermentable Extract)

End fermentation is the point at which the yeast has assimilated all the fermentable sugars it can into carbon dioxide and alcohol. This method, which reports yeast fermentable extract, %, to one decimal place, is helpful in determining the final gravity of a beer on a bench scale compared to a beer in a fermenting vessel. This allows brewing staff to monitor fermentation on a daily basis or when dealing with new products that have an unknown final gravity.

View Method

Beer 18. Iron

Iron in beer can be detrimental to its organoleptic characteristics, stability, and quality. Thus the iron content of beer should be as low as possible. Metallic notes are derived from contamination of beer with metal ions, and metallic odors can also be produced by lipid oxidation. This method determines iron content, mg/L, by colorimetry, by atomic absorption spectrophotometry, and by analysis with ferrozine.

View Method

Beer 20. Calcium

Some form of calcium is often added in the brewhouse. Calcium helps to lower the pH of the mash, can improve enzyme activity, reduces oxalate (preventing the formation of beer stone), and increases yeast flocculation. Monitoring calcium concentration in wort and to a lesser extent in beer can be a tool in consistent beer production. This method determines calcium content, mg/L, by analyses with chrome Black T indicator and calcein and by atomic absorption spectrophotometry.

View Method

Beer 21. Total Sulfur Dioxide

This method determines total sulfur dioxide content, mg/L, by the p-rosaniline method and by the segmented flow analyzer method.

Calculator: Determining Total Sulfur Dioxide using the p-Rosaniline Method

View Method

Beer 22. Foam Collapse Rate and Foam Stability

This method measures the rate of foam collapse by the Sigma value method (modified Carlsberg method) and the foam flashing method.

Calculators:

• Foam Collapse Rate – Sigma Value
• Foam Collapse Rate – Foam Flashing Method

View Method

Beer 25. Diacetyl

This method determines diacetyl content, mg/L, by the broad spectrum method for VDK, the micro dimethyl glyoxime method, and the gas chromatographic method.

Calculator: VDK Calculator*
*For use with the method Beer 25. Spectrophotometric determination of total VDK by distillation and α-naphthol creatine reaction

View MethodMaster the Method

Beer 26. Formazin Turbidity Standards

The clarity of beer, or freedom from turbidity, is an important property. Whether turbidity is present because of processing factors or as a result of aging and/or chilling of the packaged product, a means for its measurement as related to a reproducible reference turbidity is a requisite for consistent measurement and reporting of results. In collaborative studies, formazin turbidity standards have proved to provide such a reference scale. This method permits the reporting of beer turbidity in terms of formazin turbidity units.

View Method

Beer 29. Lower Boiling Volatiles in Beer or Ale

Levels of lower boiling volatiles in beer and ale can be determined by several procedures. This method determines the concentrations of ethyl acetate, n-propyl alcohol, i-butyl alcohol, the i-amyl alcohols (composed of i-amyl and active amyl alcohols), and i-amyl acetate in beer or ale by direct injection of a beer sample containing an internal standard onto a gas chromatographic column. The concentration of each of these compounds is obtained by calculating the ratio of the unknown peak to the internal standard and comparing this value to a calibration curve.

View Method

Beer 31. Free Amino Nitrogen (International Method)

The free amino nitrogen content (FAN) of a finished beer reflects primarily the utilization of wort free amino nitrogen during fermentation. Evaluation at various stages of fermentation may also be useful in charting the progressive loss. This method determines the FAN, mg/L, of finished beer.

View Method

Beer 32. Viscosity (International Method)

The viscosity of beer can be a useful figure reflecting the content and degradation state of contributory factors, such as ;Β-glucan, derived from wort. This method determines viscosity in centipoise and centistoke units and Pascal seconds.

Calculator: Viscosity – International Method

View Method

Beer 36. Sodium by Atomic Absorption Spectrophotometry (International Method)

Sodium can influence the flavor of the beer at higher concentrations depending on the style. Measurement can verify whether sodium-based cleaning solutions have adulterated wort or beer in the process, whereas pH may not show a shift. This method determines sodium concentration (mg/L) by atomic absorption spectrophotometry.

View Method

Beer 37. Potassium by Atomic Absorption Spectrophotometry (International Method)

Potassium can influence the flavor of the beer at higher concentrations depending on the style. Potassium is also critical for yeast growth and carbohydrate metabolism. This method determines potassium concentration (mg/L) by atomic absorption spectrophotometry.

View Method

Beer 38. Magnesium and Calcium

This method determines magnesium concentration (mg/L) by atomic absorption spectrophotometry and magnesium and calcium concentrations (mg/L) by sequential titration.

View Method

Beer 39. Chloride

Chloride is associated with palate fullness and contributes to the perception of body in a beer. Excessive chloride may inhibit yeast flocculation and promote corrosion of cans. Chloride in beer is determined by titrating the available chloride ion and detecting the presence of excess titrant cation occurring in solution after the end point is reached. Excess Ag+ titrant can be detected by conductivity measurement. This method determines chloride concentration (mg/L) by conductometric titration and by mercurimetric titration.

View Method

Beer 40. N-Nitrosamines

This method determines N-nitrosamines levels by distillation (results expressed in μg/L) and by celite adsorption (results expressed as μg/kg).

View Method

Beer 43. Anions (Chloride, Phosphate, and Sulfate) by Ion Chromatorgraphy (International Method)

This method utilizes ion chromatography with suppressed conductivity detection to separate and quantitate chloride, phosphate, and sulfate in beer.

View Method

Beer 44. Dimethyl Sulfide by Chemiluminescence Detection

Dimethyl sulfide (DMS) is a compound that is typically produced during wort boiling from precursors (e.g., S-methyl methionine) from germination or malting processes. This gas-chromatographic headspace method employs chemiluminescence for the detection of DMS in finished beer.

View Method

Beer 45. Elemental Analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy

This method measures calcium, copper, iron, potassium, magnesium, and sodium in finished or packaged beer by inductively coupled plasma-atomic emission spectroscopy. The instrument measures the elemental concentrations based on the emission of light for each element as the sample is passed through a plasma.

View Method

Beer 46. Measurement of Oxidative Resistance in Beer by Electron Paramagnetic Resonance

This method determines the oxidative resistance of beer. Electron paramagnetic resonance (EPR) spectroscopy is used to directly measure free radical production in the beer during a forced oxidation assay. The assay is based on an EPR-spin trapping experiment in which free radicals form covalently bound adducts with the (-phenyl-t-butylnitrone spin trapping reagent. The accumulation of these adducts is detected by EPR during the forced oxidation period and directly reflects the resistance (or lack of resistance) of the beer to oxidation. Two metrics obtained from the assay, lag time and EPR intensity at 150 min (T150) values, can be used to quantitatively assess a beer’s oxidative resistance.

View Method

Beer 48. Headspace Gas Chromatography - Flame Ionization Detection Analysis of Beer Volatiles

This method can be used to identify and quantify the generation of volatile organic compounds produced through fermentation. It is designed to measure selected beer volatile compounds in finished beer samples by headspace gas chromatography–flame ionization detection. The selected compounds evaluated through collaborative analysis were chosen to represent different chemical classes (i.e., aldehydes, esters, and alcohols) that are present in beer samples.

View Method

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

*A subset of methods in this chapter were designated as applicable. Refer to the Applicability Reference Guide for those methods determined to be not of use, not applicable, or in need of further testing.*

Yeast 1. Sampling

Since yeast slurries, suspensions, and compressed cakes can easily become stratified, sampling must be done in a manner that ensures homogeneity. This method presents the basic procedures for obtaining representative samples and preparing them for laboratory analysis.

View Method

Yeast 2. Physical Examination

The homogeneous yeast sample may be subjected to a variety of tests and examinations to determine its quality and suitability for brewing. The first sensory steps will be to record its color, character (flocculent vs. nonflocculent), odor, and taste. This will be followed by microscopic examination, as described in this method, to determine cell morphology and the presence of undesirable microorganisms, e.g., bacteria.

View Method

Yeast 3. Yeast Stains

Numerous yeast staining procedures have been investigated, either to supplement information acquired by trial under brewing conditions or to reduce the time required for such evaluation. This method describes dead yeast cell stain, yeast spore stain, the use of triphenyltetrazolium chloride for identification of respiratory-deficient cells, and determination of yeast viability by fluorescent staining.

View Method

Yeast 4. Microscopic Yeast Cell Counting

This method determines yeast cell concentration by using a hemocytometer and a microscope. The procedure relies on the enumeration of cells within a specific number of microscopic fields to determine the concentration of yeast in a population.

View MethodMaster the MethodView Demonstration Video

Yeast 5. Yeast Solids

This method determines yeast solids as total by dry weight (for liquid and pressed yeast samples) and as percent by spin-down (for slurries).

Calculators:

• Yeast Solids – Pressed Yeast Samples
• Yeast Solids – Percent by Spin-Down

View Method

Yeast 6. Yeast Viability by Slide Culture

Viability of culture yeast is of utmost importance. This method measures viability by a slide-culture technique employing a medium containing malt extract, yeast extract, glucose, and peptone supplemented with maltose and zinc.

Calculator: Yeast Viability by Slide Culture

View Method

Yeast 7. Yeast Sporulation

Yeast sporulation is useful for identification of some species of wild yeast, because lager yeast generally sporulates poorly, if at all. Sporulation can also be used to help characterize yeast and to produce spores for genetic studies. This method determines percentage of sporulated cells and typical number of spores per ascus in a sample.

View Method

Yeast 8. Killer Yeast Identification

The capacity to be killed by a killer yeast is an easily scored and well-defined phenotype. An agar plate seeded with a sensitive strain and then inoculated with a killer strain produces a clear zone of inhibition within the seeded sensitive lawn. This technique, a simple screening assay to determine whether a yeast secretes killer toxin, is described in this method.

View Method

Yeast 9. Morphology of Giant Yeast Colonies (International Method)

This method produces giant yeast colonies on wort gelatin medium. Comparative analysis of the morphology of such colonies can be used as a means of differentiating brewing yeasts.

View Method

Yeast 10. Differentiation of Ale and Lager Yeast

This method differentiates ale and lager yeasts by measuring growth of colonies on X-(-gal medium, by determining growth at 37°C, and by determining growth on melibiose.

View Method

Yeast 11. Flocculation

This method measures flocculation of a yeast sample by the Helm assay, in which sedimentation of a yeast sample is observed in a calcium sulfate solution buffered at pH 4.5 to determine sedimentation volume and flocculation type, and by the absorbance method, in which flocculation is measured by absorbance after a settling reaction in a calcium sulfate solution buffered at pH 4.5.

View Method

Yeast 12. Vitality By Fluorescence

This method is included as a Provisional Method and should provide a guideline for the use of the Yeast Activity Monitor instrument for vitality analysis at the discretion of the user. The method was not recommended for inclusion in Methods of Analysis due to the criteria outlined in the method.

View Method

Yeast 13. Differentiation of Brewing Yeast Strains by PCR Fingerprinting

Brewing yeast strains can be differentiated on the basis of their DNA structure and composition. While there are many DNA fingerprinting methods available, polymerase chair reaction offers a quick and simple process for the differentiation of strains. This method describes the process in which oligonucleotide primers that bind to complementary regions within yeast delta sequences are used to produce a DNA fingerprint.

Calculator: Yeast Strains by PCR Fingerprinting PCR Mix Calculator (Excel worksheet)

View Method

Yeast 14. Miniature Fermentation Assay

Small-scale wort fermentation (15-mL volumes) can be used to assess malt for premature yeast flocculation behavior and to compare the fermentability of yeast strains. This method may also be applied to malt treatments (or problem versus control malts) by performing the method simultaneously on all treatments. The method also includes a system for assessing (or comparing) malt performance quantitatively.

View Method

Yeast 16. Phenolic Yeast Detection By Decarboxylation Of Ferulic Acid

This method is intended for the detection of yeast able to decarboxylate ferulic acid, resulting in the formation of 4-vinyl guaiacol (4-VG or 2-methoxy-4-vinylphenol). Detection is based on a sensorial aromatic assessment to determine whether a phenolic clove-like or smokey attribute is present. The method is limited to the sensorial skills of the assessor and the amount of 4-VG produced by a yeast strain.

View Method

Yeast 17. FastOrange^TM Yeast Detection

This method is intended for enrichment of yeast strains utilizing FastOrange^TM yeast agar media and application of the agar media to analyze samples. The media is designed to inhibit bacteria and allow for yeast growth. Growth typically occurs in conjunction with a color change from violet to yellow. Some bacteria may be capable of growth in the media. Microscopic examination should be used in conjunction with growth and color change for all assessments to determine whether growth is yeast or bacteria.

View Method

Microbiological Control 1. Aseptic Sampling

This method analyzes microbial populations in brewery air (reported as number of colonies/volume of air examined) and provides a general swabbing procedure to be utilized to determine the hygiene of brewery surfaces using adenosine triphosphate (ATP) bioluminescence detection instrumentation.

**1B is NOT APPLICABLE.

View MethodView Demonstration Video

Microbiological Control 2. Detection of Microorganisms

This method provides incubation and plating procedures for the detection, enumeration, and partial characterization of viable microorganisms in liquid samples and a membrane filtration technique that is recommended for examination of beer, rinse water, or similar samples that contain relatively few bacteria, yeast, or molds.

View MethodMaster the Method

Microbiological Control 3. Differential Staining

Identification of bacteria may be facilitated by differential staining. This method identifies brewery contaminants by using the Gram stain procedure.

View Method

Microbiological Control 4. General Culture Media

This method provides instructions for preparing two media (universal beer agar and brewers’ tomato juice medium) that can be used for general microbiological control work in the brewery. Most culture yeast, nonculture yeast, and Gram-negative rods commonly found in breweries grow well on these media under standard conditions. Lactic acid organisms commonly found in breweries, such as Lactobacilli and Pediococci, grow well on these media under anaerobic conditions. When supplemented with cycloheximide, these media differentially suppress the growth of brewing yeast. A safer alternative to cycloheximide is nystatin.

View Method

Microbiological Control 5. Differential Culture Media

Differential media have provided additional means for identifying microbiological contaminants in the brewery. This has been achieved by differential antibiotic action or by medium composition that suppresses the growth of one type of microorganism or enhances the growth of another. This method provides instructions for preparing cycloheximide medium, Lee’s multi-differential agar, Raka-Ray lactic acid bacteria medium, lysine medium, Lin’s wild yeast differential medium, Barney-Miller brewery medium, De Man Rogosa Sharpe medium, MYGP + copper medium, CLEN medium for wild yeast, selective medium for Megasphaera and Pectinatus, nystatin in selective media, Hsu’s Lactobacillus and Pediococcus medium, and FastOrange^TM Brett agar media for Dekkera/Brettanomyces.

View MethodView Demonstration Video

Microbiological Control 6. Water and Rinse Water Hygiene Using ATP

Bioluminescence provides a rapid, real-time assessment of microbial load (bacteria and yeast) in brewery water, including rinse water samples obtained after sterilization or cleaning of equipment. This test utilizes the reaction of adenosine triphosphate (ATP) with luciferin/luciferase to generate quantifiable bioluminescence that is detected using a luminometer. The data obtained may be used to provide an immediate assessment of hygiene or to complement traditional routine microbiology tests.

View Method

Common Brewery-Related Microorganisms

View Guide

*A subset of methods in this chapter were designated as applicable. Refer to the Applicability Reference Guide for those methods determined to be not of use, not applicable, or in need of further testing.* 

Bottles 1. Dimensions 1999

The dimensions of beer and ale bottles are critical to the smooth operation of packaging machinery. Specifications and tolerances must be set in accordance with the requirements of the equipment and the glass vendor’s process capability. This method measures height, outside diameter, out-of-perpendicular, identification marks, glass distribution, weight, locking ring “A” diameter, reinforcing ring “B” diameter, width of locking ring, throat “I” diameter, and finish.

View Method

Bottles 2. Defects

This method provides general definitions to aid in understanding terms expressing the degree or seriousness of a bottle defect or an accumulation of defects.

View Method

Bottles 3. Color

This method measures the amber color of bottle glass spectrophotometrically and by redness ratio.

View Method

Bottles 4. Capacity

This method determines the overflow and fill point capacities of beer and ale bottles.

View Method

Bottles 5. Surface Protective Coatings

This method evaluates the performance characteristics of durable lubricating coatings on glass in two ways: lubricity and coating quality. The first is a measure of the coefficient of friction between coated glass containers, while the second is a measure of the abrasion protection provided by the coating. Permanently coated nonreturnable bottles can be evaluated by the dry and wet rub test procedures.

View Method

Bottle Closures 1. Defects Glossary and Classification

This glossary contains general definitions that specify the terms expressing the degree or seriousness of a defect or accumulation of defects for plastic-lined crowns and closures, including closure shell defects, plastic liner defects, and lithography defects.

View Method

Bottle Closures 2. Test Pressure

This method determines the amount of pressure a bottle crown will withstand when subjected to a uniformly increasing internal pressure with the crown applied to a steel bottle finish and to a standard glass bottle finish; the amount of pressure a 28-mm topside pilferproof closure will withstand when subjected to a uniformly increasing internal pressure with the closure applied to a steel bottle finish and to a standard glass bottle finish; the amount of pressure a plastic-lined convenience two-way crown applied to GPI 500 series finishes will withstand when subjected to a uniformly increasing internal pressure; and tests the integrity of the bottle-closure seal.

View Method

Bottle Closures 3. Gas Retention Capability of Crowns

This method measures the gas-retention capability of cork-lined and plastic-lined crowns.

View Method

Bottle Closures 4. Lithography Resistance to Pasteurization Conditions for Steel Crowns and Roll-On Pilferproof Aluminum Closures

This test simulates the exposure of a crimped crown or an applied roll-on pilferproof closure to the caustic solutions that are present in a conventional pasteurizer. Some lithographic materials may be less tolerant to exposure than others. However, crown manufacturers usually have prescreened these coating materials for best pasteurization bath resistance. This test is used only as a confirmation test when problems are noted on crowns or closures that have exited pasteurization during production conditions.

View Method

Bottle Closures 5. Removal Torque Procedure

This method estimates the average and variation of removal torques from a given lot of aluminum closures or a given lot of crowns and a given lot of bottles.

View Method

Bottle Closures 6. Crimp Determination Test -- Crowns

This method determines crimp diameter after crown application. Proper crimp is essential to prevent leakage.

View Method

Cans 1. Defects Classification and Glossary for Seamless Two-Piece Cans

Can and end defects require classification to reduce misunderstandings of terms, while at the same time expressing the area of influence for the defect or accumulation of defects. This method defines terms used to describe can and end defects.

View Method

Cans 3. Dimensions

This method measures metal gauge thickness of cans and ends, coated or uncoated; flange width; and the countersink depth of a filled, closed can.

View Method

Cans 4. Ends

This method measures the curl opening of beverage ends and the fit of an end to a seaming chuck and determines the force required to open ring-pull-ends.

View Method

Cans 5. Capacity

This method measures the overflow capacity of cans and the headspace of a can at stated contents.

View Method

Cans 6. Enamel Rater for Evaluating Metal Exposure

This method provides a rating of can quality in terms of metal exposure and a location site of the exposure by using an enamel rater. Average, minimum, and maximum metal exposure values and the standard deviation are determined.

View Method

Cans 7. Beverage Can Terminology

This document defines the standard terminology used to describe different parts of a beverage can and can end. It is designed to be used for reference for methods that use can terminology.

View Method

Cans 8. Copper Sulfate Test

This method determines whether there are any exposed metal surfaces on the interior of containers coated with a polymer material. It is designed primarily for the testing of aluminum cans and ends coated with internal coating (IC), but it can be used for containers made with other metals such as steel. A galvanic reaction occurs when the copper from the copper sulfate is deposited on the surface in locations where the surface is not covered with IC. This method detects potential pinholes and pores in the IC or places where the container may contain improper coverage of the IC on the interior.

View Method

Fills 1. Total Contents of Bottles and Cans by Calculation from Measured Net Weight

This method calculates the contents of bottles and cans (in fl oz) from measured tare weight.

View Method

Fills 2. Total Contents of Cans of Known Tare Weight

This method calculates the contents of cans (in fl oz) from known tare weight.

View Method

*A subset of methods in this chapter were designated as applicable. Refer to the Applicability Reference Guide for those methods determined to be not of use, not applicable, or in need of further testing.* 

Maintaining a Beverage Library Best Practice

A beverage library is a collection of packaged samples from each production run produced at a brewery. Building and organizing a library of packaged beverages is a best practice for every brewery's quality program, allowing for the easy retrieval and analysis of past batches to address potential quality concerns.

View Guideline

Sensory Analysis 1. Terms and Definitions (International Method)

This section defines the principal concepts and methods used in sensory analysis of brewery products. For individual flavor terms, see Sensory Analysis-12.

View Method

Sensory Analysis 2. Test Room, Equipment, Conduct of Test (International Method)

The equipment and procedures described in this method are designed to cover the requirements of brewery panel testing of beer, wort, water, and other liquid products. The panel tasks considered in this method include not only difference testing, descriptive tests, and quality control tasting, but also panel training, threshold testing, investigation of off-flavors, plant project tasting, and new product development.

View MethodMaster the Method

Sensory Analysis 3. Choice of Method (International Method)

In sensory analysis, a given problem frequently requires appreciable thought before an appropriate practical test is selected because the initial conception of the problem may require clarification. This method discusses the choice of a test relevant to a given problem

View Method

Sensory Analysis 4. Selection and Training of Assessors (International Method)

The procedures described in this method are suitable for establishing and maintaining a resident sensory panel to be used for difference tests, threshold tests, and descriptive tests of beer, wort, water, and other brewery samples. This method does not apply to consumer panels used for preference tests.

View Method

Sensory Analysis 5. Author Guidelines for Reporting (International Method)

Procedures described in this method report the results of sensory tests on samples of beer, wort, water, or other brewing materials or intermediate products. The reports can be used for publication purposes or for internal use at the brewery.

View Method

Sensory Analysis 6. Paired Comparison Test (International Method)

The test described in this method is used for the following purposes: (a) Directional Difference Test –to determine in what way a particular sensory characteristic differs between two samples (e.g., more sweet or less sweet); (b) Paired Preference Test–to establish whether a preference exists between two samples (e.g., in consumer tests); and (c) Assessor Training–to select, train, and perfect assessors.

View Method

Sensory Analysis 7. Triangular Test (International Method)

This method is used to determine whether any two samples of beer, wort, in-process samples, water, or other brewery samples are significantly different or whether the samples are significantly similar. The method is the same for testing for difference and similarity, but the statistical parameters selected for the evaluation of results and the minimum number of assessors required is different. Typically, more assessors are needed to test for similarity than to test for difference. Use of the method is recommended when the nature of the difference between samples is unknown. It does not determine the size or direction of the difference, and the attribute or attributes responsible for the differences are not identified. The method also applies whether a difference exists in a single attribute or in several. It is applicable only when the products do not cause excessive sensory fatigue, carryover, or adaptation. In these cases, use another test, for example, the duo-trio test, taking into account that this test has a lower statistical power. The method can also be used to select, train, and monitor assessors.

View Method

Sensory Analysis 8. Duo-Trio Test (International Method)

The test described in this method determines whether a sensory difference is apparent between two samples. It can be applied to any two samples of beer, wort, water, or other brewery samples, whether the difference(s) to be expected involves all sensory attributes or one specific attribute (odor, sweetness, etc.). The assessors are first presented the identified reference sample. This is followed by two coded samples, one of which is identical to the reference sample. The assessors are asked to identify the odd sample.

View Method

Sensory Analysis 9. Threshold of Added Substances -- Ascending Method of Limits Test (International Method)

The test described in this method determines the lowest concentration of an added substance that can be detected by odor or taste. The threshold may be determined to: (a) learn whether a substance present in beer is likely to exert an effect on its flavor; (b) provide an indication of the magnitude of any such effect; (c) study the relative sensitivities of individuals to the test substance; and (d) select, train, and perfect assessors.

View Method

Sensory Analysis 10. Descriptive Analysis (International Method)

This method is used with trained tasters to obtain a systematic description of the flavor of samples under test, for example, in the evaluation of test brews, or in quality control, or to train and perfect assessors. Additionally, this method can be used to profile competitors of a brand to determine differences among your beers and other leading brands. Apply the test to any beer, wort, water, and other brewery samples or, more frequently, to any group of 2-6 samples to be compared.

View Method

Sensory Analysis 11. Ranking Test (International Method)

The test described in this method is used to place a series of test samples (usually from three to six) in rank order according to a given characteristic (criterion). The criterion may be the intensity of a single sensory attribute, or a group of related attributes, or a total impression.

View Method

Sensory Analysis 12. Flavor Terminology and Reference Standards (International Method)

This method describes an internationally accepted flavor terminology system for beer. It names and defines each of 122 separately identifiable flavor notes that can occur in beer. Approved flavor reference standards or procedures are provided for 27 terms, and suggestions are given for 15 additional substances.

View Method

Sensory Analysis 13. Difference-from-Control (International Method)

The test described in this method is used when the test objective is twofold: 1) to determine whether a sensory difference is apparent between samples; and 2) to estimate the magnitude of any such difference. If the purpose is to prove similarity between two samples, the test does not apply.

View Method

Sensory Analysis 14. Hot Steep Malt Sensory Evaluation Method

The hot steep method is a rapid and standardized wort preparation method for the sensory evaluation of extractable malt flavor. This method is designed to be practical and affordable.

View MethodMaster the MethodView Demonstration Video

Sensory Analysis 18. Tetrad Test

This test method covers a procedure for determining whether a statistically significant sensory difference exists between samples of two different products. This method of discrimination is more statistically efficient and powerful than the triangle test and therefore requires fewer panelists.

View Method

Sensory Analysis 19. Shelf-Life Determination with the True-to-Brand Method

Having an understanding of a brand's shelf life is essential for delivering on consumer expectations, understanding opportunities for quality improvement, and communicating with distributors and retailers. This method adapts the straight-forward true-to-brand method, which focuses on each beverage's baseline brand profile and an individual company's threshold for risk for shelf-life work.

View MethodMaster the MethodView Guideline to Maintaining a Beverage Library

All methods in this chapter were designated as applicable.  View full chapter to access these methods. 

*A subset of methods in this chapter were designated as applicable. Refer to the Applicability Reference Guide for those methods determined to be not of use, not applicable, or in need of further testing.* 

Glossary

View Glossary

Wort 1. Sampling

Wort analysis may be required, or desired, with a variety of worts produced under different conditions. All worts have one thing in common–they are not completely stable and are subject to microbial, physical, and chemical deterioration. Accordingly, cooling rates, clarification procedures, and handling of wort samples must be standardized before comparison of analytical results can be made. This method is used to obtain representative wort samples and to prepare them for chemical and physical analyses.

View Method

Wort 2. Specific Gravity

This method measures specific gravity by use of a digital density meter.

View Method

Wort 3. Extract

This method reports extract (°Plato) of wort to two decimal places.

View Method

Wort 5. Yeast Fermentable Extract

This method determines yeast fermentable extract of wort (%) by use of regular fermentation and by rapid fermentation procedures.

Calculator: Yeast Fermentable Extract – Rapid Fermentation

View Method

Wort 7. Total Acidity

This method calculates total acidity (as lactic acid) (%).

Calculator: Total Acidity

View Method

Wort 8. pH (Hydrogen Ion Concentration)

This method determines the pH (hydrogen ion concentration) of a wort sample.

View Method

Wort 10. Protein

This method determines protein (% by weight) by the Kjeldahl method and by combustion.

View Method

Wort 11. Reducing Sugars (Copper Reducing Substances)

This method determines reducing sugars (% by weight) of wort samples.

View Method

Wort 12. Free Amino Nitrogen (International Method)

This method determines free amino nitrogen (FAN) in wort by three methods: the ninhydrin method, segmented flow analysis, and automated discrete analysis. The ninhydrin method can be used to determine the amount of FAN in wort or beer to provide information regarding the quantity of amino nitrogen available to yeast during fermentation, or the quantity of amino nitrogen remaining in beer after fermentation. The method measures amino acids, ammonia, and, to some extent, end-group y-amino nitrogen in peptides and proteins. The method is not specific for a-amino nitrogen since y-aminobutyric acid, which is present in both wort and beer, yields substantial color with ninhydrin. Segmented flow analysis is an automated procedure that can be used for determination of FAN in wort. The FAN concentration is determined based on the ninhydrin reaction. The sample is diluted and mixed with ninhydrin reagent, is incubated for a specified time, and absorbance is determined at 570 nm. The concentration of FAN in the sample is proportional to absorbance at 570 nm. The automated discrete analysis procedure for determination of FAN is based on the reaction of primary amines with o-phthaldialdehyde (OPA). Reactions are performed at 37°C, and the intensity of absorbance is measured at 340 nm.

View Method

Wort 13. Viscosity

Viscosity of wort may be measured for a variety of reasons, including comparison of worts from brew to brew, evaluation of processing changes or new malt varieties, and gathering of engineering data required for the design of equipment. The information required, therefore, determines the type of result and the units of reporting. This method calculates absolute or dynamic viscosity (in centipoise units or Pascal-seconds) and kinematic viscosity (in centistokes) using a viscometer and according to the Hoeppler principle by measuring the rolling time of a ball through an inclined glass capillary filled with wort at 20°C.

View Method

Wort 14. Fermentable Saccharides by Chromatography

Evaluation of potentially fermentable carbohydrates in wort by gas and liquid chromatography is discussed in this method. Evaluation of brewery wort is complicated by the presence of carbohydrates derived from the mashing of malt and those that may be derived, in varying degree, from adjunct materials, including sugars and syrups.

View Method

Wort 15. Magnesium by Atomic Absorption Spectrophotometry

Application of atomic absorption spectrophotometry in the analysis of beer for iron, copper, calcium, sodium, potassium, and magnesium is described in other methods. Its use has been extended to the analysis of wort for magnesium and is described in this method.

View Method

Wort 16. Zinc by Atomic Absorption Spectrophotometry (International Method)

Application of atomic absorption spectrophotometry in the analysis of beer for iron, copper, calcium, sodium, potassium, and magnesium is described in other methods. Its use has been extended to the analysis of wort for zinc and is described in this method. This method differs from the analysis of magnesium in wort (Wort-15) in requiring a wort addition standard curve.

View Method

Wort 17. Protein in Unhopped Wort by Spectrophotometry

The method provides a relatively simple and rapid means of measuring the soluble protein content of unhopped laboratory wort based on the differing UV absorptions of protein at 215 nm and 225 nm.

Calculator: Protein in Unhopped Wort by Spectrophotometry

View Method

Wort 18. β-Glucan in Congress Wort

This method measures the ß-glucan content of congress wort by fourtechniques. The first exploits the chemistry of the fluorochrome Calcofluor to bind to 1,3- and 1,4-ß-D-glucan. Flow injection analysis is utilized to quantify ß-glucan in congress wort. Segmented flow analysis is used in the second technique. The principle of the methodology involves diluting the wort sample with distilled water and mixing with a Calcofluor reagent, which results in the formation of a fluorescent adduct, cellufluor-ß-glucan (1). The fluorescence intensity of the complex is measured. The fluorescence peak height of the complex is proportional to the concentration of ß-glucan in the wort sample. The third procedure employs a spectrophotometric method to determine ß-glucan content using the GlucaTest Rapid Test kit. The fourth method is an automated discrete analysis procedure that determines ß-glucan content based on the reaction of the sample mixed with Calcofluor reagent. The intensity of the absorbance of the Calcofluor ß-glucan complex is measured.

View Method

Wort 19. Fermentable Carbohydrates by Cation Exchange HPLC

Diluted worts are injected into a high-performance liquid chromatography system. A cation exchange column with water as mobile phase is used to separate the sugars, which are then measured by a refractive index detector. Sugars having a degree of polymerization of 1-3 are quantitatively determined by comparison with aqueous standards containing fructose, glucose, maltose, and maltotriose.

View Method

Wort 20. Elemental Analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy

The method measures magnesium (mg/L) and zinc (g/L) in wort by inductively coupled plasma-atomic emission spectroscopy. The instrument measures the elemental concentrations based on the emission of light for each element as the sample is passed through a plasma.

View Method

Wort 22. Wort and Beer Fermentable and Total Carbohydrates by HPLC

Identification and quantification of fermentable and total carbohydrates in samples throughout the brewing process and in final products are determined by high-performance liquid chromatography (HPLC). Samples are introduced into the HPLC system to be chromatographically separated and quantified by the two methods described.

View Method

Wort 25. Rapid Malt Color

The color of malt is determined by preparing an extract using a microwave oven and subsequently measuring the absorbance of the filtered extract at 430 nm using a spectrophotometer.

View Method