Malt Quality Analysis Descriptions

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 note 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

Test

(links to more info)

Description

Ideal Range

General Methods to increase

General Methods to decrease

Barley Measures
 Barley Protein
 This value is measured on raw barley prior to malting and is highly impacted by variety, crop management (fertilization, dry/irrigated) and environment. 9-12%

Have a relationship with your farmer - this trait is highly impacted by variety and management

Moisture

Barley moisture impacts longevity of a barleys Germinative Capacity and its resistance to spoilage. Cooler/dryer conditions greatly increase the length of time barley can be stored. Careful/continual monitoring during storage is important to maintain quality.

Table for storage lengths at different temps and moistures.		 11-13% Too low conditions can lead to loss of husk and grain breakage during handling which will negatively impact the overall malting process – have a relationship with your farmer if moisture is too low Have a relationship with your farmer. Environmental conditions may require harvesting at higher moisture, but grain must be dried down for storage. Determine how and where barley will be stored and ensure that conditions allow longevity of the barley to match your need.
Plumps 6/64
 Measure of kernel diameter. Related to extract potential and protein. Influenced by 2 row/6 row, crop year and variety >90% Have a relationship with your farmer, consider variety and management practices. Post-harvest cleaning/conditioning of barley is also important. Some malt houses may separate barley via sieve then malt portions separately to improve homogeneity with blending after malting, or discarding thin portions as feed etc.

 

 

 

N/A
Germinatioin Characteristics
 Germinative energy (GE - % at which barley germinates), Germinative capacity (GC - ability of barley to germinate), and Water Sensitivity (WS - barleys tendency to germinate or not with long periods of submersion). These characteristics are impacted by environment, timing, and storage of barley.

GE: >95%

 

GC: >95%

 

WS: <20%

It is important to start with high quality barley which has not been impacted by pre-harvest sprouting. Varieties vary in their level of dormancy and higher levels can offer some protection against sprouting – but may also need more time to break before they can be malted.

WS – N/A

GE/GC – N/A

Water sensitivity is not fully understood but thought to be impacted by variety and environment. There is no way to reduce water sensitivity, only management of the issue by adjusting steeping to reflect the needs of the barley, i.e. shortening length of time under water in later steeps of a cycle.
 DON
 DON – short for deoxynivalenol - is a byproduct toxin of a disease called Fusarium Head Blight (FHB) or Scab. Occurrence of this disease is environmental. <1.0 ppm

 

 

 

N/A

 Have a relationship with your farmer. Resistant varieties and management practices (such as fungicide and crop rotation) can reduce the occurrence and/or severity of Fusarium. For low level occurrences really good washing, over flow during steeping and long storage to lower viability of Fusarium may be methods for management.
 Falling Number -or- RVA
 Two different methods both used in measuring the level of pre-harvest sprouting (PHS) a grain may have undergone

Falling#: >300

 

RVA:

>120

 

 

N/A

 Have a relationship with your farmer. If you are in an area prone to PHS select varieties which have inherent dormancy/resistance.

Malt Measures
Total Protein
  Highly correlated to barley protein, slightly reduced due to the malting process – this value is measured on malted barley kernels. 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.  <11.8%  Total protein is largely determined by the initial protein of the barley – low total proteins are likely due to low barley protein and/or over modification.  Malt protein is largely determined by the initial protein of the barley, although a small decrease may be evident due to the removal of rootlets, which are protein rich, (but a small portion of the total weight). If you are seeing high malt protein it is likely due to use of high protein barley
Plumps on 6/64 screen
  Malt plumps are directly related to barley plumps but may be impacted by any screening processes a malt house conducts prior to malting.  >90%
 
 *See barley plumps
Friability

 

Friability video

  Friability is 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  >80%  Be selective of the variety you are using, aware of the quality of your endosperm hydration at steep out, use barley with good germination characteristics, and generally increase your modification  Friability can be too high, which would indicate over-modification and loss of extract. Monitor things like acrospire length at end of germ to ensure you are not over-modifying the grain
Moisture
  Excess moisture leads to increased shipping costs, flavor loss, reduced brew house yield, and there is risk of microbial activity above 6%. Low 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"
  Total 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 brew house yield and overall performance. Influenced by 2 row/6 row and variety.  

Two row: >81.5%

 

Six-row: >78% 		 Over and under modification reduces extract. Be aware of the quality of hydration you are achieving during steeping – un-hydrated 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 = 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  Commonly, <10 NTU (quite clear)  N/A - Generally the goal is to have low turbidity. There are multiple ways for brewers to introduce haziness to their beer, if they want it, without hazy worts  Ensure you have balanced modification, protein is not too high, A-amylase is not too low, don’t re-circulate too much CO2 which can encourage microbial growth during germination
 Viscocity
(absolute cp, cp= centipoise)
  Viscosity is largely a measure of the breakdown of B-glucans (endosperm cell walls) during malting. Highly viscous worts can cause throughput problems in the brewery  1.4-1.45cp

 

 N/A - goal is to have low viscosity

  Improve modification to lower B-Glucan. Viscosity can also be influenced by inclusion of dead kernels, variety and other barley aspects such as arabinoxylan - a cell wall component of the aleurone.
 B-Glucan
  High B-glucan contents in wort are related to poor malt modification and/or dead kernels and can cause slow lautering/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 ppm

 

 N/A - generally the lower the better

  Improve modification - be aware of the quality of embryo hydration - in order for B-glucanase to act/break down B-glucan there must be hydration
 Soluble Protein
  Protein that has been broken down to soluble form – this measurement is taken on the wort. 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%  Increase modification. If you have good modification and 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 lengths 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.

Table of typical malt color ranges by type

 

 

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 mg/l

  

Choose a higher protein barley, increase modification

 

Choose a lower protein barley, be aware of over modification.
pH

This is a good diagnostic tool for the malster

 The brewer uses pH values to adjust liquor acidity for a 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: 5.8-6.0

Ale malts- lower end

Lager malts- higher end

 

  Control over pH in malt is not well understood – more research needed

Low values may mean problems in germination (no enough oxygen, microbial issues etc.) High color malts have low wort pH values (this is normal) and wheat malts have high pH values >6.0

 Alpha Amylase
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).   40-70 DU  Potential AA is inherent to a particular lot of barley. Low levels may be increased by ensuring vigorous germination out of steep (need adequate temps) and with time - longer germination = higher AA. Also monitor use of re-circulated air, high CO2 levels can "choke" barley and reduce AA production.

 

 

 Decrease germination time, increase CO2 circulation during germination
Diastatic Power
  Roughly a measure of B-amylase. Important in starch and adjunct breakdown. Influenced by protein, variety, and kiln conditions  110-150 °ASBC  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 and protease levels. As malting progresses, total protein is broken down (modified) into smaller more soluble proteins.  38-45%

 

Monitor modification - increase modification to increase S/T

 

 Decrease modification to decrease S/T