Malt Quality Analysis Descriptions

Montana State University Quality Lab

 Malt Modification

During the malting process, each kernel produces enzymes that break down seed proteins, carbohydrates, and other reserves. It is critical that conversion of these seed reserves (malt modification) take place in a balanced and uniform manner. Uneven malt modification will result in processing problems in the brewery including malt milling, poor wort and beer filtration, hazes, poor yeast growth, and off flavors.

 

 *Please not that the ideal ranges listed here are for base malts  intended for all malt brewing and methods for increasing and decreasing each parameter are generalizations -individual situations may require different remedies

 

 Description

Ideal Range

General Methods to increase

General Methods to decrease

Malt Measures

 

      
Total Protein Malt protein is the progenitor of many important qualities such as enzyme activity, color production and yeast nutrients. The controlling factor in malt protein is the protein contained in the barley as a starting material. In turn this is related to growing conditions (fertilization, moisture, environment) as well as variety  9-12% Have a relationship with your farmer - this trait is highly impacted by variety and management  
Plumps on 6/64 screen Measure of kernel width. Impacts mill settings. Influenced by 2 row/6 row, crop year and variety  >90%  Have a relationship with your farmer, consider variety and management practices.  
Friability Friability: the condition of being friable, describes the tendency of a solid substance to be break into smaller pieces under duress. A general indication of malt modification, influenced by malt process, variety, and protein. Correlated w/ B-glucan and F/C difference    Be selective of the variety your are using, be aware of the quality of your endosperm hydration at steep out, use barley with good germination characteristics, generally increase your modification  N/A - generally you would not be interested in decreasing
Moisture Excess moisture leads to  increasee shipping costs, flavor loss, reduced brewhouse yield, and there is risk of microbial activity above 6%. Deficient moisture can result in shattering of husks, excessive dust during milling and poor extraction due to difficulty in wetting. Influenced by kilning process and storage.   4-5.5%  Primarily a function of your kilning regime - longer periods in the kiln will drive off more moisture and vice versa. Moisture values can shift in malt during storage so it is important to have a cool/dry location.  

Wort Measures

        
Extract (FG db)
“Fine Grind dry basis”		 Toral soluble content of the malt which dissolves during mashing to produce wort - primarily a measure of the amount of carbohydrates recovered from malt during mashing. It is a function of grain modification and enzyme activity. General indicator of brewhouse yield and overall performance. Over modification reduces extract and increases soluble protein. Influenced by 2 row/6 row and variety.

Two row: >81.5%

 

Six-row: >78%

  Be aware of the quality of hydration you are acheiving during steeping - unhydrated endosperm will not modify. Be sure to use high quality barley with good germination characteristics, reasonable protein, and high plumps.  N/A - goal is to have high extract
Turbidity (NTU)
NTU = Nephelometric Turbidity Units		 Measure of clarity. Hazy worts may be caused by insufficient protein degradation, insufficient degradation of B-glucans, and high concentrations of phenolic compounds  Can depend on end product, commonly <10 NTU (quite clear)  Generally the goal is to have low turbidity in worts produced from malt. There are multiple ways for brewers to introduce haziness to their beer, if they want it, generally without needing hazy worts  N/A
Viscosity (absolute cp)
cp = centipoise		 Viscosity is a measure of the breakdown of B-glucans (endosperm cell walls) during malting. Highly viscous worts can cause throughput problems in the brewery.  1.4-1.45 N/A - goal is to have low viscosity Improve modification to lower B-Glucan (cell wall component of endosperm). Viscosity can also be influenced by inclusion of dead kernels, variety and other barley aspects such as arabinoxylan - a cell wall component of aleurone cell walls.
Beta-Glucan (ppm) High B-glucan contents in wort are related to poor malt modification and/or dead kernels. High B-glucan contents can cause slow lautering and filtration times and haze in beer. Influenced by crop year and environment. High B-glucan correlates w/ low S/T, high viscosity, turbid worts, low friability, and can be a cause of low extract.  <100  N/A - generally the lower the better  Improve modification - be aware of the quality of embryo hydration - in order for B-glucanase to act/breal down B-glucan there must be hydration.
Soluble Protein Soluble protein provides the basis for yeast nutrition, foam retention and beer color. Excessive levels can lead to hazy beer. Influenced by the amount of total protein and degree of modification. Usually correlated with Free Amino Nitrogen (FAN).  4.5-5.5% Increae modification. If you have good modification are you using barley with very low protein, consider higher protein as a starting material.  High soluble protein may be due to over modification - be aware of acrospire lenths at the end of germination
Color (°ASBC) A major component of final beer color. Color is also indirectly related to flavor. Color is developed during kilning from sugar and soluble protein precursors.  Depends on end product  Longer periods at higher temps in kiln  Lowering kiln temps, slower drying

FAN

(Free Amino Nitrogen

 Amino acids are required for yeast nutrition and proper fermentation. FAN forms during the malting process and is correlated w/ soluble protein  150-180  Choose a higher protein barley, increase modification  Choose a lower protein barley, be aware of over modification.
pH The brewer uses these pH values to adjust liquor acidity for the particular lot of malt so that the ultimate mash and wort pHs end up within the optimum range of 5.2-5.3.

 Base malts: 5.8-6

Ale malts- lower end

Lager malts- higher end

    
Alpha Amylase (DU)
DU = Dextrinizing Units		 One of the key enzymes in breaking starch down into fermentable sugars (cuts starch so B-amylase can work). Influenced by variety, malting, and application of Gibberellic Acid (GA). A good vigorous start to germination and lengthening time in germination during malting help to increase the finall level. 65-75  Potential AA is inherent to a particular batch ofbarley and increases with vigorous germination out of steep (ensure adequate temps) and with time - longer germination = higher AA. Also monitor use of re-circulated air, high CO2 levels can "chocke" barley and reduce AA production.  Decrease germination time, increase CO2 circulation during germination

Diastatic Power

(°ASBC)

 Roughly a measure of B-amylase. Important in starch and adjunct breakdown. Influenced by protein, variety, and kiln conditions.  100-115  Use higher protein protein barley, reduce temperature of kilning regime  Use lower protein barley
F/C Difference
(Fine/Course Grind)		 In theory, this is a measure of modification, with smaller values representing better modification and vice versa.   <2%  Improve modification  N/A - generally smaller differences are better
S/T Protein
(Soluble/Total)

Direct measure of protein modification. Influenced by malting. As malting progresses, total protein is broken down (modified) into smaller more soluble proteins.

  39-43%  Monitor modification - increase modification to increase S/T  Decrease modification to decrease S/T