Malts And Malting(1).pdf

Malts and Malting

Dennis E. Briggs

Preface

About 15 years have passed since the appearance of the 2nd edition of Malting and Brewing

Science. Many changes have occurred in the intervening years, not least the early death of James

S. Hough, the retirement of Roger Stevens and the closure of the Birmingham-based British

School of Malting and Brewing. For a time it seemed impossible to undertake another revision of

Malting and Brewing Science. Furthermore a need for a more extensive treatment of malts and

the malting process was recognized. In consequence, this volume was prepared. It is the author's

intention that the `brewing science' will be covered by another book in the future.

Malting, one of the earliest `biotechnologies', is a fascinating blend of pure and applied sciences

(including plant and microbial biochemistry and physiology, chemistry, physics and engineering)

with personal skills and judgements, all being used with industrial and commercial restraints and

requirements in view. In a little more than one century, malting has evolved from an `art' to a

(nearly) routine production process. The differences between grain samples from different areas,

grown in different years, and varietal differences as well as variations in users' requirements will

never permit the production of malt to become a `merely routine' process. The present book,

which emphasizes principles rather than the details of malting, outlines the uses to which malt is

put. Then the intention has been to describe the various aspects of malts and malting to give a

sound technical introduction to understanding the various topics involved. A complete account of

the history of malting has not been attempted, but some historical information is given both for

its intrinsic interest and because the rich records of malting trials and practice cannot be

understood without it. Deciding how much information to include has been difficult. For

example, while the text includes some discussion of analytical methods, the details of these

methods will have to be sought in the official, definitive publications, which are cited. As far as

possible, measurements are given in metric units, with equivalents in imperial, American and

traditional units, when this is appropriate. The equivalence - and lack of true equivalence -

between some units is explained. The Appendix contains tabulations of units and some other

useful data. The, apparently antiquarian, description of some older units is strictly necessary

since, unless they are understood, maltsters cannot follow the older reports and literature. This

constitutes an enormous store of useful data and observations. It is hoped that the limited number

of references cited will be sufficient to give an entry into the more specialized literature.

Inevitably many key contributions have not been individually acknowledged. Those who need to

delve further should consult the collective indices of the major journals and the relevant

computer-based data banks.

The inadequacy of the acknowledgements to individuals for help received is a source of

embarrassment. I hope it will be forgiven when I explain that in the last 36 years I have always

received friendly and generous help from any maltster I have approached with a reasonable

request for assistance, and help was also nearly always given when the requests were less than

reasonable. These helpful friends numbered over 100 when I gave up counting and they have

been or are connected with most of the malting companies in the UK and with several overseas. I

thank them all for making the preparation of this book an interesting and enjoyable activity. I

hasten to add that any faults that may be present are mine.

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Malts and Malting

Dennis E. Briggs

I would like to thank four people without whose help the exercise would have failed: Mrs S.

Maltby for her typing from my imperfect manuscripts; Mrs P. Hill for drawing and redrawing

diagrams and Mrs M. Pass whose efforts in supplying information have been unstinting.

Above all I must thank Rosemary, my wife, for unfailing support and good humoured resignation

as yet another morning was spent writing. I also thank those who have provided data or have

permitted me to use, in original or modified forms, various diagrams and tables. These are

acknowledged in the text.

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Malts and Malting

Dennis E. Briggs

Abbreviations

°G

SG-1000

°L

degrees Lintner (diastatic power; DP)

°W-K

degrees Windisch-Kolbach (diastatic power; DP)

70 °C viscosity

viscosity of wort from a small analytic mash, made at 70°C

ASBC

American Society of Brewing Chemists

BOD

biological oxygen demand

brl

barrel (volume; see Appendix)

c. conc. mash

coarse ground grist in a concentrated analytical mash

c.g.

coarse grind

CIP

cleaning in place

coag.N

coagulable nitrogen

COD

chemical oxygen demand

centipoise (unit of viscosity)

CWE

cold water extract

d.b.

dry, basis

d.wt.

dry weight

dextrose equivalent

DFP

diisopropyl fluorophosphate

d.m.

dry matter

DMS

dimethyl sulphide

DMS-P

dimethylsulphide precursor (SMM)

DMSO

dimethylsulphoxide

diastatic power

dextrinizing units (a-amylase)

EBC

European Brewery Convention

EBC unit

unit of colour

EDTA

ethylenediamine tetraacetic acid

F(app.%)

apparent percentage fermentability (attenuation)

F(real, %)

real percentage fermentability

f.-c. extract

difference in hot water extract yields obtained with finely

difference

and coarsely ground samples of malt

f.g.

fine-grind

f.wt.

fresh weight

FAN

free amino nitrogen

fermentable extract

formol N

nitrogen fraction reacting with formaldehyde

germinative capacity

germinative energy

GKVs

germination and kilning vessels

GLC -FID

gas-liquid chromatography using a flame ionization detector

GLC -TEA

gas-liquid chromatography using a thermal energy analyser

hectolitre

HMF

hydroxymethylfurfural

HMW-N

high-molecular-weight nitrogen

HPLC

high performance liquid chromatography

HWE

hot water extract

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Malts and Malting

Dennis E. Briggs

IoB

Institute of Brewing '

Kolbach index

pounds weight or brewers' pound of extract

LOX

lipoxygenase

m.c.

moisture content

m/m

mass/mass

MAFF

Ministry of Agriculture, Fisheries and Food

measurable cyanide

min

minute(s)

malting loss

mPa/s

millipascal/s (units of viscosity)

MRL

maximum residue limit

malt yield

nitrogen

NDMA

N-nitroso-dimethylamine

NIAB

National Institute of Agricultural Botany

NIR

near infrared spectroscopy

NMR

nuclear magnetic resonance

NPN

non-protein nitrogen

original gravity (water = 1000)

p.p.b.

parts per billion

p.p.m.

parts per million (usually mg/1 or mg/kg)

present gravity (water = 1000)

PSN

permanently soluble nitrogen

PSY

predicted spirit (alcohol, ethanol) yield

permanganate values for COD

PVPP

polyvinylpolypyrrolidone

quarter (various values; see Appendix)

water-absorbing power (das Quellvermögen)

r(95)

repeatability value

R(95)

reproducibility value

relative humidity

respiratory quotient

second(s)

SASPL

saturated ammonium sulphate precipitation limit

specific gravity (water = 1000)

SGKVs

steeping, germination and kilning vessels

SGVs

steeping and germination vessels

SMM

S-methylmethionine

SNR

soluble nitrogen ratio

SOD

superoxide dismutase

tonne (1000 kg)

TCW

thousand corn weight

total nitrogen

TSN

total soluble nitrogen

v/v

volume/volume

water sensitivity

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