1. STEPS IN BREAD MAKING OPERATIONS
FERMENTATION- PHYSICAL / CHEMICAL
FERMENTATION CONTROL
GAS PRODUCTION
GAS RETENTION
FERMENTATION LOSSES
KNOCK BACK
DOUGH MAKE-UP- DIVIDE/SCALE/INTERMEDIATE PROOF/MOULDING
PANNING
FINAL PROOF
BAKING / STEAMING / COOLING

2. 1. FERMENTATION
PHYSICAL CHANGES
INCREASE IN VOLUME
INCREASE IN TEMPERATURE BY 5˚- 6˚C
INCREASE IN NO. OF YEAST CELLS ( 26%-STRAIGHT DOUGH/ 56% IN SPONGE)
LOSS OF MOISTURE
CHANGE IN CONSISTENCY – SOFT, ELASTIC , EXTENSIBLE.
CHEMICAL CHANGES
Ph REDUCES FROM 5.5 TO 4.7 DUE TO PRODUCTION OF ACETIC, LACTIC,SULPHURIC AND
HYDROCHLORIC ACIDS
FORMATION OF MALTASE BY DIASTATIC ENZYMES ACTING ON STARCH
PRODUCTION OF CO₂ AND ALCOHOL BY ENZYMATIC REACTIONS
MELLOWING OF GLUTEN BY PROTEOLYTIC ENZMES
FERMENTATION TIME DEPENDS ON
-TYPE OF FLOUR
-QUANTITY OF YEAST
-TEMPERATURE OF DOUGH
-PRESENCE OF YEAST FOOD

3. ENZYMES
ENZYMES ARE PROTEINS AND A GIVEN ENZYME WILL WORK ONLY ON A CERTAIN
SUBSTRATE AND ONLY DO A VERY SPECIFIC JOB
ALTHOUGH THEY TAKE PART IN A CHEMICAL REACTION, THEY DO NOT CHANGE
THEMSELVES
BECAUSE THEY ARE PROTEINS ,THEY ARE HEAT SENSITIVE
THEY HAVE AN OPTIMUM TEMPERATURE AND Ph FOR ACTIVITY
WITHIN THAT RANGE, ACTIVITY INCREASES WITH TEMPERATURE UNTIL
DENATURATION POINT IS REACHED.
THE 3 MAIN ENZYMES COMMONLY ENCOUNTERED IN THE BAKERY ARE:-
1. AMYLASES i.e. α AMYLASE AND β AMYLASE.
2. PROTEASES. THEY REACT WITH PROTEINS AND WEAKEN THEM THEREBY
REDUCING MIXING TIME AND IMPROVING MACHINEABILITY.
3. LIPOXYGENASES. THIS ENZYME FOUND IN SOY FLOUR BLEACHES THE FLOUR
THEREBY GIVING A WHITER CRUMB.

4. AMYLASES
AMYLASES CONVERT STARCH INTO SUGARS.
α AMYLASE CLEAVES THE STARCH RANDOMLY INTO SMALLER UNITS CALLED DEXTRINS.
β AMYLASE CUTS OFF 2 UNITS AT A TIME FROM THE END OF THE STARCH CHAIN.
THE MORE α AMYLASE THERE IS, BETTER FOR THE β AMYLASE BECAUSE THERE ARE MORE
EXTREMITIES AVAILABLE.
SO THE SUBSTRATE FOR THE β AMYLASE IS EITHER STARCH OR DEXTRINS AND THE PRODUCT
IS MALTASE.
FLOURS TEND TO LACK α AMYLASE AND THE MILLER HAS TO SUPPLEMENT THIS. EITHER FROM
A CEREAL SOURCE(MALTED BARLEY), FUNGAL SOURCE OR A BACTERIAL SOURCE.
MALT IS PRODUCED BY GERMINATING BARLEY WHERE THE KERNEL PRODUCES A LOT OF
ENZYMES, MAINLY AMYLASES AND PROTEASES.
WHEN THESE ENZYMES ARE EXTRACTED, IT LEADS TO DIASTATIC MALT SYRUP- i.e. IT
CONTAINS ACTIVE ENZYMES. IT IMPROVES DOUGH HANDLING, PROVIDES MORE FOOD FOR
YEAST, FLAVOUR, CRUST AND CRUMB COLOUR AND INCREASES SHELF LIFE.
NONDIASTATIC MALT IS TREATED IN SUCH A WAY THAT THE ENZYMES WILL DENATURE
( DEACTIVATED). IT AIDS IN FERMENTATION, CRUST AND CRUMB COLOUR AND FLAVOUR.
THE ACTIVITY OF ALPHA AND BETA AMYLASE IS KNOWN AS DIASTATIC ACTIVITY.

5. 2. FERMENTATION CONTROL
IT IS IMPORTANT TO HAVE THE DEVELOPMENT OF GAS PRODUCTION AND GAS
RETENTION CAPACITIES AT A PARALLEL AND EVEN RATE.
3. GAS PRODUCTION
INCREASES WITH ADDITION OF SUGAR AND MALT/ YEAST / YEAST FOOD/ HIGH TEMP
OF THE DOUGH (35˚C)
DECREASES WITH ADDITION OF SALT/ EXCESS YEAST FOODS/ EXCESS TEMP (>35 ˚C)
4. GAS RETENTION
DEPENDS ON CHEMICAL AND PHYSICAL FACTORS SUCH AS MINERALS, MOISTURE,PH,
PROTEOLYTIC ENZYMES AND OXIDIZING AGENTS, MIXING, DOUGH EXPANSION, KNOCK
BACK, DIVIDING, ROUNDING AND MOULDING.
5. FERMENTATION LOSSES.
AVERAGE CONDITIONS WEIGHT LOSS IS 1% ( 0.5-4%). DUE TO LOSS IN MOISTURE WHICH
DEPENDS ON TEMP. AND RELATIVE HUMIDITY AND A LITTLE TO CO₂ ESCAPE.

6. 6. KNOCK BACK
EXPELS CO₂, ADDS NEW OXYGEN THEREBY STIMULATES YEAST ACTIVITY, EQUALISES DOUGH
TEMPERATURE, INCREASES GAS RETENTION CAPACITY AND AIDS MECHANICAL
DEVELOPMENT OF GLUTEN.
7. DOUGH MAKE UP
DIVIDE, SCALE, ROUND, INTERMEDIATE PROOF AND MOULDING
8. PANNING.
PLACING THE MOULDED DOUGH SEAM DOWN INTO A GREASED PAN
9. FINAL PROOF
RELAXES THE DOUGH, GIVES GOOD, MELLOW AND EXTENSIBLE GLUTEN.
10. BAKING
THE MOST IMPORTANT STEP IN BREAD MAKING.

7. BAKING – PHYSICAL CHANGES
1. FILM FORMATION (CRUST)
2. OVEN SPRING. THE SUDDEN EXPANSION OF THE DOUGH DUE TO EXPANSION OF GASES
AND FINAL YEAST ACTIVITY BY ABOUT 1/3rd THE ORIGINAL SIZE.
3. OVEN SHRED. THE FINE STRETCH MARKS VISIBLE AT THE SIDES OF THE LOAF SHOWING
A WELL CONDITIONED DOUGH AND GLUTEN.
BAKING – CHEMICAL CHANGES
1. YEAST ACTIVITY
2. STARCH SWELLS AND GELATINIZES FROM ABOUT 54˚C
3. GLUTEN COAGULATION WHICH SETS IN AT ABOUT 74˚C
THE MAJOR CHANGE IS THE REDISTRIBUTION OF WATER FROM THE GLUTEN
PHASE TO THE STARCH PHASE.
4. ENZYME ACTIVITY. AMYLASE ACTION ON STARCH INCREASES UP DENATURIZATION
BETWEEN 57˚C AND 72˚C.
5. SUGAR CARAMELIZATION.
6. BROWNING REACTION. STARTS AT 160˚C. IT IS THE RESULT OF HEATING AND REDUCES
SUGARS WITH FREE AMINO ACIDS, PEPTIDES OR PROTEINS TO FORM COLOURED
COMPOUNDS CALLED MALANOIDINS ( GIVES COLOUR AND FLAVOUR TO BREAD)
STEAMING –GLOSSY CRUST/PREVENTS SPLIT CRUST/ AGITATES EVEN ATMOSPHERE
COOLING