Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

Подождите немного. Документ загружается.

flavors, and create an attractive finish. Sweeteners

also increase tenderness, crust color, volume, and

moisture retention, while maintaining the proper bal-

ance between liquids and solids responsible for prod-

uct contour/shape. Machining properties and baking

characteristics are also closely related to sugar. Sweet-

eners tenderize the finished product by interfering

with gluten hydration and starch gelatinization. (See

Sweeteners: Intensive.)

0012 High-fructose corn (maize) syrups are becoming

increasingly important, but sucrose from sugar cane

or beet is still the major sweetener. Commercial

sugars are often categorized as granulated or

powdered. Granulated sugars range from coating

sugar (extremely fine grain) to coarse. Powdered

sugars are made by grinding granulated sugars and

screening through fine bolting cloths. Generally, as

the size of the sugar crystal increases, the size and

symmetry of the biscuit decrease, while the thickness

and color increase. Often anticaking agents, e.g., corn

starch, are added to insure proper flow of the sugar

during raw material handling. Where pumpability

may offer a processing benefit, granular sucrose can

be combined with water to form ‘liquid sugar,’ usu-

ally at 67% sugar solids or 67



Brix.

0013 Sucrose may be hydrolyzed (inverted) to glucose

(dextrose) and fructose (laevulose) by heating it in

the presence of a dilute weak acid or mixing it with

invertase enzyme. Sucrose is the standard for sweet-

ness, with an arbitrary rating of 100. Fructose and

glusose are rated at 170 and 74, respectively. Their

combined sweetness in a completely inverted sugar

is 127, sweeter than the starting sucrose. Inverted

sugars are used primarily for their hygroscopicity

and browning reactions, which contribute moisture

retention and color development in the biscuits. (See

Carbohydrates: Sensory Properties.)

Shortenings and Emulsifiers

0014Fats are the third major component used in biscuit

making, but are considerably more expensive than

flour or sugar. Besides being used in the doughs, fats

or oils are used as surface sprays, in cream fillings and

coatings (such as chocolate), and as release agents. In

dough, they tenderize (impart shortness to) the crumb

by being dispersed in films and globules during

mixing, which interferes with gluten development.

Shortening also aids dough aeration during the

creaming step. The overall effect improves palatabil-

ity, extends shelf-life, improves flavor and, of course,

adds caloric energy. (See Fats: Uses in the Food

Industry.)

0015Animal fats, primarily lard, were originally used by

bakers. Compound (part animal and part vegetable

source) shortenings and all-vegetable shortenings

were then developed. Soya bean, cottonseed, palm,

coconut, and peanut oils are the primary vegetable

sources used in shortening production. Continued

advancements in purification and hydrogenation de-

veloped vegetable oils that could replace animal fats

with equal or better flavors, melting points, consist-

ency, and availability. Because of current health con-

cerns, most bakeries have switched to fats of plant

origin. (See Vegetable Oils: Types and Properties.)

0016Surfactants (surface-active agents) are given many

names by bakers: crumb softeners, emulsifiers, anti-

staling agents, or dough conditioners. Examples

include lecithin, mono- and diglycerides, diacetyl

tbl0002 Table 2 Representative formulae for various cracker types

Ingredient Snack cracker % Soda (saltine) % Graham %

Strong flour 66.37 69.60 25.40

Soft flour NA NA 25.40

Graham flour NA NA 12.60

Water 18.10 21.58 16.40

Granular sugar 3.85 NA 7.62

Shortening 3.85 6.61 5.08

Ammonia bicarbonate 2.05 NA 0.38

Corn syrup 1.90 NA NA

Malt syrup 1.28 0.64 0.44

Brown sugar or honey NA NA 4.64

Meal 0.96 NA NA

Sodium bicarbonate 0.71 0.44 0.63

Salt 0.60 0.97 0.89

Monocalcium phosphate 0.30 NA 0.25

Protease 0.03 NA NA

Lecithin NA NA 0.25

Optional seasonings As desired NA 0.02

Yeast NA 0.16 NA

NA, not applicable.

BISCUITS, COOKIES, AND CRACKERS/Chemistry of Biscuit Making 535

tartaric acid esters of fatty acids, polysorbate 60 and

sodium stearloyl 2-lactylate. Surfactants at low con-

centrations act to modify the surface behaviors of

liquids. They are believed to complex with the pro-

tein–starch structure, thereby strengthening the film,

and to delay dough setting during baking. The behav-

ior of surfactants is due to their amphoteric (possess-

ing both hydrophilic and hydrophobic molecular

regions) properties. Their behavior varies according

to the charges on the molecules, their solubility, the

hydrophilic–lipophilic balance, and the type of

functional groups involved. (See Emulsifiers: Uses in

Processed Foods.)

0017 Surfactants modify dough consistency and reduce

stickiness by reacting with the gluten. The greasiness

of biscuits with high fat content is also reduced by

surfactants. Crumb softeners also complex with the

starch molecules to delay retrogradation and texture

staling. The grain pattern and volume of the finished

product are often improved, as surfactants increase

dough gas-retaining properties.

0018 Antioxidants retard the development of oxidative

rancidity during product storage. All fats are subject

to oxidative or hydrolytic rancidity which causes ob-

jectionable odors and flavors, but antioxidants delay

these reactions from occurring within the biscuits’

shelf-life. They are usually added to bulk shortenings

and are important for preserving low-moisture prod-

ucts, which are expected to remain edible for several

months. (See Antioxidants: Natural Antioxidants;

Synthetic Antioxidants.)

Is Water an Ingredient?

0019 Water is often thought of as a processing aid or cata-

lyst, rather than as an ingredient. It is incorporated at

the dough stage but driven off during baking. Water

functions in several ways, including hydrating flour

proteins and starch, dissolving sugars, salts, and vari-

ous leavening chemicals, aiding in ingredient distribu-

tion and helping control dough temperature.

0020 A dough’s consistency is directly related to its water

content, or absorption. Many factors affect dough

absorption. Approximately 46% of flour’s total

absorption is associated with the starch, 31% with

protein, and 23% with the pentosans. Acceptable

consistency can be obtained only after sufficient

water is present to hydrate the flour. This is regarded

as bound water and controls the dough’s consistency.

As bound water layers are ‘stacked up,’ some of the

water is held less and less strongly, resulting in water

that can escape (evaporation) and/or migrate as

free water. Water activity (a

) is an important way

to measure and monitor water’s mobility in baked

products.

Making Biscuits Lighter

0021Leavening agents aerate the dough or batter to make

it light and porous. The leavening action is respon-

sible for good volume, improved eating quality, and a

uniform cell structure. Leavening can be achieved by

various methods, including yeast fermentation, the

mechanical incorporation of air by mixing and

creaming, formation of water vapor during baking,

and the creation of carbon dioxide and/or ammonia

by chemical leaveners. However, creation of the

initial air bubbles during the mixing phase is critical

before any of the other leavening agents can take

effect. (See Leavening Agents.)

0022Small products like biscuits that bake quickly need

a fast-acting leavener that will release the gas before

the structure sets. The most widely used source of

carbon dioxide in chemically leavened systems is the

reaction of sodium bicarbonate or baking soda

(NaHCO

) with an acid, usually the acidic salt of

a weak mineral acid. The leavening acid promotes a

controlled and nearly complete evolution of carbon

dioxide from sodium bicarbonate in an aqueous solu-

tion. Some examples include monocalcium phosphate

monohydrate (CaH

)

O), sodium acid pyro-

phosphate (Na

) and potassium acid tartrate

(KHC

). When these agents combine with

water, they react to form controlled amounts of

carbon dioxide. Sodium bicarbonate also raises

dough pH.

0023Ammonium bicarbonate (NH

HCO

) generates

carbon dioxide, ammonia, and steam when heated.

It increases spread and gives a larger, more desirable

surface ‘crack’ in some types of hard, high-sugar bis-

cuits. However, it can be used only with low-moisture

biscuits that are baked sufficiently to drive off all

residual ammonia.

Other Ingredients

0024Milk products, eggs, and salt are added for variety.

Milk and eggs are viewed as wholesome ingredients

by consumers; however, they are among the most

expensive.

0025Milk and whey are good sources of protein and

lactose, which aid in shape retention and browning

reactions. They add flavor and nutrients, improve

texture, crust color, moisture retention, and control

spread. They are usually added in dried form. (See

Whey and Whey Powders: Production and Uses.)

0026Eggs contribute color, structure, nutritional value,

and some flavor. They affect texture as a result of

their emulsifying, tenderizing, leavening, and binding

actions. The form of eggs used can be fortified or

whole components (yolks and whites) in the liquid,

frozen or dried state, or combined with sugar.

536 BISCUITS, COOKIES, AND CRACKERS/Chemistry of Biscuit Making

0027 Salt performs two principal functions in biscuit

doughs. The first is flavor. It accentuates or potenti-

ates the flavor of other ingredients (e.g., the sweetness

of sugar is emphasized), and it removes the flatness or

lack of flavor in other foods. Moreover, salt has a

slight effect on the consistency of hard doughs,

because it has a strengthening effect on gluten. Salt

also controls fermentation and aids in suppressing

undesirable bacteria.

0028 Minor ingredients include malt, proteases, mold

inhibitors, spices and flavorings. Though used in

relatively small amounts, these ingredients have

quite important effects on the sensory and physical

qualities of biscuits.

0029 Malt is prepared from barley by sprouting it, then

drying it at controlled temperatures. Diastatic malt

provides enzymes that break starch into simple sugars

and add flavor and color. If the malt is heated suffi-

ciently to inactivate the (amylase) enzymes, for use as

a flavorant, it is called ‘nondiastatic.’ (See Malt:

Chemistry of Malting.)

0030 Proteases are important in crackers (low sugar).

They are often added to modify the gluten frame-

work. The effect of a protease is to make the dough

less elastic, so that shrinkage does not occur during

sheeting and cutting. Proteases may occasionally be

used in cookie production. A dough containing gluten

that is too strong will decrease biscuit spread, so

proteases can improve the spread ratio. (See Enzymes:

Uses in Food Processing.)

0031 Mold inhibitors are not generally used in low-

moisture cookies and crackers, but some types

which are higher in moisture may benefit from their

inclusion. Other food products used in biscuits (i.e.,

fillings, toppings, and creams) may require an

inhibitor. Some examples include sodium diacetate

(Na

.HC

. ½H

O), calcium propion-

ate (Ca(CH

COO)

) and sodium propionate

(CH

COONa).

Added Flavors

0032 Our choice of food is largely influenced by taste and

flavor. Smell, taste, touch, and sight are all influenced

by the chemical and physical properties of the food.

Sweet bakery foods are often selected for this reason.

Therefore, selecting the correct flavor is extremely

critical. Selection of the best flavor is most often

achieved through experience and trial and error. (See

Flavor (Flavour) Compounds: Structures and Charac-

teristics.)

0033 Biscuits may be flavored in one or more of three

ways: adding the flavoring to the dough before

baking; dusting or spraying the flavor on after baking;

or by flavoring a nonbaked portion such as cream

filling, icing, or jam that is applied after baking.

0034Spices are aromatic vegetable products (tree bark,

seeds, fruits, and roots), and are usually finely

ground. They improve quality through smells and

tastes. The most commonly used spices are cinnamon,

mace, nutmeg, caraway, anise, allspice, poppy seed,

coriander, ginger, cloves, and fennel.

0035Flavorings are alcohol extracts from fruits or

beans. Vanilla is the most common because it blends

with and enhances other flavors. Flavorings, such as

vanilla or almond, can be either natural or synthetic.

Because flavorings are volatile, much of them may be

lost during baking.

Added Colors

0036Color additives are used in biscuits and in fillings,

icings, and coatings to create a perception of quality

and richness. (See Colorants (Colourants): Properties

and Determination of Natural Pigments; Properties

and Determinants of Synthetic Pigments.)

Chemical Changes During Baking

0037Biscuits are usually baked in a tunnel oven. The

dough pieces are placed on either a flexible metal or

wire mesh band that travels continuously through the

oven’s length, which may reach 100 m. Baking is

controlled by varying the temperatures in the individ-

ual zones within the oven. It is not uncommon for the

drier to consist of 5–7 zones. Baking time is regulated

by the band speed. Crackers and some biscuits are

docked by pressing blunt pins into the dough sheet.

Docking dough pieces before baking creates air pas-

sages through the crust and seals the top to the

bottom, reducing big blisters.

0038Dough undergoes several changes during baking

(Figure 2). Changes in dimension and texture, loss

of moisture, and color and flavor development are

the most important. Baking is divided into three

phases. The first involves dough expansion and the

start of moisture loss. Dough expansion and water

Baking time

Property

fig0002Figure 2 Physical changes in biscuits during baking. Key:

—

—, color; —, thickness;

...

, weight.

BISCUITS, COOKIES, AND CRACKERS/Chemistry of Biscuit Making 537

loss reach maximum rates and colour development

starts during the second phase. The third phase con-

cludes baking with a lower rate of moisture loss,

thinning of the biscuit, and increasing surface color.

Dimension and Texture Changes

0039 As dough pieces enter the oven, the biscuit’s internal

temperature rises, and the sugars and fats melt. The

complex matrix contains liquified fat and dissolved

sugars. Water evaporation causes the solution to

become more concentrated, and the dough tempera-

ture continues to increase. Leaveners and steam cause

the dough volume to expand. With sufficient heat,

limited protein denaturation and starch swelling

occur, helping to create some structure. However,

the high sugar and fat content inhibit full starch

gelatinization.

0040 Doughs rich in fat and sugar, but containing little

water, often have unhydrated proteins and ungelati-

nized starch when baked. With this formulation, a

rigid structure cannot be achieved, and is therefore

replaced by a soft, sugary matrix. During baking, the

dough expands greatly via steam and leavening, but

does not set properly, resulting in collapse of the

biscuit upon removal from the oven. This expan-

sion–collapse effect is responsible for the characteris-

tic cracked surface of some biscuits.

Moisture Loss

0041 Dough moistures average 11–30% before baking and

1–5% after. Moisture can be lost only from the biscuit

surface. It migrates from the center to the surface of

the biscuit by capillary action and diffusion. The free

water is evaporated very readily, but part of the

bound water will also be liberated, in association

with color development. Moisture content and

water activity are critical parameters, as both directly

influence storage life.

Color Changes

0042 One of the most important color reactions is the

Maillard reaction. It involves the interaction of redu-

cing sugars with amino groups in the proteins, mainly

from lysine, and produces an attractive reddish-

brown hue. It is also associated with the dextriniza-

tion of starch and the caramelization of sugars. These

reactions require very high temperatures, which are

reached only at the biscuit surface. (See Browning:

Nonenzymatic.)

Storage and Staling

0043 Most freshly baked biscuits are cooled before pack-

aging or secondary processing, e.g., icing or sand-

wiching with a cream filling. Snack crackers are

sprayed with oil and salted/seasoned prior to cooling.

The cooling period is usually 15–2 times longer than

the baking period. During cooling and storage, the

biscuit continues to undergo texture changes. Hard

dough biscuits are rigid and crisp immediately after

baking. Soft dough products are still flexible at the

end of baking, but become firm and crisp after

cooling, as a result of sugar recrystallization and

glass transition temperature.

Changes in Moisture Distribution

0044The residual moisture is not uniformly distributed as

a biscuit leaves the oven. Most of the moisture lies in a

lamella near the center, leaving the surface and the

outer periphery almost dry.

0045‘Checking’ is a change associated with uneven

moisture distribution. Dimensional changes within

the biscuit after baking cause it to crack. The center

shrinks as it loses moisture, but the rim expands as it

absorbs moisture. Checking can happen in almost any

type of biscuit or cracker, but is most commonly

found in semisweet products.

See also: Bread: Chemistry of Baking; Browning:

Nonenzymatic; Carbohydrates: Sensory Properties;

Colorants (Colourants): Properties and Determination of

Natural Pigments; Properties and Determinants of

Synthetic Pigments; Emulsifiers: Uses in Processed

Foods; Enzymes: Uses in Food Processing; Fats: Uses in

the Food Industry; Flavor (Flavour) Compounds:

Structures and Characteristics; Flour: Roller Milling

Operations; Analysis of Wheat Flours; Dietary

Importance; Malt: Chemistry of Malting; Vegetable Oils:

Types and Properties; Whey and Whey Powders:

Production and Uses

Further Reading

Blanshard JMV, Frazier PF and Gailliard T (1986) Chemis-

try and Physics of Baking. London: Royal Society of

Chemistry.

Fennema OR (1976) Principles of Food Science. New York:

Marcel Dekker.

Manley DJR (1983) Technology of Biscuits, Crackers and

Cookies. Chichester: Ellis Horwood.

Matz SA (1991) The Chemistry and Technology of Cereals

as Food and Feed, 2nd edn. New York: Van Nostrand

Reinhold/AVI.

Matz SA (1992) Cookie and Cracker Technology, 3rd edn.

McAllen, TX: Pan-Tech International

Pomeranz Y (1978) Wheat Chemistry and Technology, 2nd

edn. St Paul, MN: American Association of Cereal

Chemists.

Pyler EJ (1988) Baking Science and Technology, 3rd edn.

Kansas City, MO: Sosland.

Smith WH (1972) Biscuits, Crackers, and Cookies: Tech-

nology, Production, and Management. Barking: Applied

Science.

538 BISCUITS, COOKIES, AND CRACKERS/Chemistry of Biscuit Making

Stauffer CE (1990) Functional Additives for Bakery Foods.

New York: Van Nostrand Reinhold/AVI.

Sultan WJ (1986) Practical Baking, 4th edn. Westport: AVI.

Wade P (1988) Biscuits, Cookies and Crackers, New York:

Elsevier.

Wafers

K Tiefenbacher, Vienna, Austria

Background

0001 Wafers – thin, crisp and precisely shaped products

from cereals – are a very special part of the biscuits,

cookies, and crackers area. The name covers several

types of wafers, quite different in recipes, manu-

facturing equipment, and end use. The fundamental

steps of making flat wafers, hollow wafers, molded

cones, rolled wafer cones, and wafer sticks are out-

lined in some detail.

0002 Concepts like water activity and glass transition

are of critical importance here. Moreover, the func-

tion of wafers as a part of combined food products is

discussed. Finally, some important trends in both

products and manufacturing equipment should be

noted.

Main Wafer Features

0003 Wafers are baked as sheets, cones, and sticks or with

different fancy shapes. The characteristic features

with respect to other bakery products are:

0004 Wafers are very thin biscuits; the overall thickness

is usually between less than 1 and 5 mm. They

often have a typical ‘wafer pattern’ on one surface

or on both. The surfaces are smooth and precisely

formed, with the dimensions and all the details –

engravings, logos, etc. – of the baking molds. See

Figure 1 for some examples.

0005 Wafers are cereal-based low fat products made of

wheat flour, sometimes with addition of other

flours or starches. The product density is in the

range of 0.10–0.25 g cm

3

. In cross-section, the

wafer matrix is highly aerated and primarily of

gelatinized starch.

0006 Wafers, by their typical delicate and crisp texture,

combine well with different fillings (cream, ice-

cream, foam) and coatings.

There is sometimes confusion in terminology between

the crisp ‘wafers’ as described here and ‘waffles,’

which are of a soft, cake-like texture but show some

kind of wafer pattern, too.

Basic Wafer Types

0007There are two basic types of wafers:

0008No- or low-sugar wafers. After baking, these con-

tain from zero to a very low percentage of sucrose

or other sugars. Typical products are flat and

hollow wafer sheets, molded cones, cups, and

fancy shapes.

0009Higher-sugar wafers. Well over 10% of sucrose

or other sugars are responsible for the plasticity

of the hot, freshly baked sheets. These are formed

into different shapes before sugar recrystallization

occurs. Typical products are rolled sugar cones,

rolled wafer sticks or tubes, and deep-formed

fancy shapes.

(a)

(b)

(c)

(d)

fig0001Figure 1 Wafer products.From top to bottom: (a), molded cones;

(b), flat wafers, creamed/enrobed; (c), hollow wafer pieces;

(d), wafer sticks.

BISCUITS, COOKIES, AND CRACKERS/Wafers 539

As in both wafer types, the main ingredient is flour,

wafers fit very well into current dietary recommenda-

tions to consume more cereals. They are high-carbo-

hydrate, low fat products. (See Cereals: Dietary

Importance.)

0010 The baking of ‘wafers’ between hot metal plates

has been known since medieval times, but these first

wafers were more similar to our waffles or pancakes

in their high fat and egg contents and their texture.

0011 Modern wafers are low-fat cereal products, very

similar to the altar breads for Christian churches,

and are basically made out of flour and water. The

first wafer ovens were used after World War I, but

more automatic manufacturing lines have been avail-

able since the mid-1950s.

Wafer Recipes

001 2 Before creating a wafer recipe, two main questions

have to be answered:

0013 What is the end use of the wafer? If it is part of

a cream-filled, chocolate-covered biscuit, where

contributing a crisp texture element is far more

important than the taste of the wafer itself, recipes

with few components are recommended. If the

wafers are consumed directly as wafer bread or

wafer sticks, more sophisticated recipes are

chosen.

0014 What kind and quality of raw materials are avail-

able? Low- to medium-protein soft wheat flours

with a low water absorption work best, especially

for no-sugar wafers. Problems with suboptimal

flours must be balanced by variations in minor

ingredients in the recipe. The use of wholemeal

flour is possible, and in some regions, other cereals

such as rice or corn are used for wafer production.

Table 1 lists the common ingredient ranges for both

types of wafer.

In-line Manufacturing of Wafer Biscuits

0015Wafer biscuits are the most important products by

volume. To explain the different steps of manufactur-

ing, we follow Figure 2.

Batter Preparation (Figure 2, process 1)

0016Wafers are made from a fluid batter with a typical

viscosity in the range of 300–2000 mPs. First, the

water-soluble components are dissolved. By adding

the farinaceous ingredients, a homogenous sus-

pension, the ‘wafer batter,’ is obtained within a few

minutes of mixing.

Batter Transport and Depositing (Figure 2,

process 2)

0017From an intermediate tank via a ring main, the batter

is pumped to the oven and spread on to the baking

molds by a depositor head.

Wafer Sheet Baking (Figure 2, process 3)

0018The baking of wafer sheets is performed in ‘tongs,’

i.e., pairs of cast-iron metal plates with a hinge and

tbl0001Table 1 Wafer batter ingredient ranges (weight parts, flour

¼100)

No (low)-sugar wafer Higher-sugar wafer

Wheat flour 100 100

Water 120–160 100–140

Starch 0–12 0–5

Sucrose 0–4 25–75

Oil/fat 0.5–2 1–6

Milk powder 0–2 0–2

Soya lecithin 0.2–1 0.2–1,5

Salt 0–0.6 0–0.6

Sodium bicarbonate 0.1–0.5 0–0.3

Optional minor ingredients: other cereal flours, soya flour, other sugars

and syrups, egg-based ingredients; whey powder, yeast, caramel color,

cocoa powder, colors, ammonium bicarbonate, enzymes.

45 6 7 8 9

fig0002 Figure 2 Manufacturing line for creamed and enrobed wafer biscuits from flat wafers. (1), batter preparation; (2), batter transport

and depositing; (3), wafer sheet baking; (4), wafer sheet cooling; (5), conditioning of sheets; (6), creaming and wafer book building;

(7), cooling and cutting of books; (8), enrobing; (9), cooling of enrobed pieces; (10), packaging.

540 BISCUITS, COOKIES, AND CRACKERS/Wafers

latch on opposite sides. Baking plate sizes up to

350  730 mm are available. The precisely machined

baking plates carry reedings or other engravings. We

call the resulting wafers ‘flat’ wafer sheets, with an

overall thickness of no more than 2–5mm.

001 9 But such baking plates can also carry special figures

(nuts, sticks, hemispheres, fancy shapes) up to a depth

of approximately 20 mm, thus yielding the so-called

‘hollow’ wafer sheets.

002 0 Modern wafer-baking plates often are surface-

plated, e.g., with chromium for easier release and

reduction of cleaning stops. The plates are edged

with metal strips to give a closed baking mold, except

for small venting channels for steam release. Wafer-

baking ovens frequently have 32–104 pairs of plates,

continuously circulating on a chain. They are mostly

gas, sometimes electrically heated and operate at

mold temperatures between 160 and 190



0021 The baking process Within a few seconds after

batter deposition, the baking molds close and are

locked. At first, the batter is distributed mechanically,

but then the mold is filled completely by the steam

that evolves. A small quantity of batter is extruded as

baking waste ‘bobbles’ through the venting channels.

As gelatinization of starch starts immediately, the

pressurization of the mold by steam occurs at the

right moment, resulting in a well-aerated starch foam.

002 2 When most of the water has been driven off, the

glass temperature of the wafer matrix rises, and

the stable structure is formed. The temperature of

the wafer increases to 160–190



C, the temperature

of the baking mold. Then, from Maillard reactions,

the typical wafer color and flavor develop. (See

Browning: Nonenzymatic.)

002 3 The overall baking times are between 1.5 and 2.5

min, depending on the wafer thickness and baking

temperature.

002 4 During the wafer manufacturing process, there is

no substantial degradation of starch molecules com-

pared with other bakery products such as extruded

cereals. Therefore, wafers have two unique textural

properties:

0025 Extreme crispness on biting and initial chewing.

0026Good mouth feel during prolonged chewing and

swallowing owing to the absence of sticky, glutin-

ous stimuli.

Wafer Release and Cooldown (Figure 2, process 4)

0027At one end of the oven, the plates open to release the

baked sheets and to spread fresh batter, and then

reclose very quickly. The sheets are cooled to room

temperature while passing over an arch-type sheet

cooler.

Wafer Conditioning (Figure 2, process 5)

0028Next, the wafers optionally pass a conditioning unit,

where the moisture content of the sheets is carefully

increased so as to achieve some stability in both the

texture and size of the wafer.

0029Moisture sorption and wafer texture After baking,

the residual moisture is 0.8–1.5%. Looking to the

sorption isotherm, this corresponds to a water activ-

ity of around 0.1 or even lower. As both the water

activity of the air in the production area and the

water activity of filling creams or coatings are well

above that, wafers pick up moisture very easily. In

line with this sorption, the dimensions of the sheet

increase by 0.2–0.3% for every 1% of additional

moisture. This can result in cracking of the coating

in enrobed wafer biscuits.

0030To compensate for the low water activity, humidity

conditioning up to approximately 4.5% wafer mois-

ture is possible. This is recommended, especially if

enrobed or chocolate molded wafer products are

made, in order to anticipate this first dimension

increase and to avoid any cracking of the coating

during its shelf-life.

0031Moreover, with increasing water activity, the wafer

texture changes from a soft to a harder crispness,

accompanied by a higher mechanical stability, which

is good both for handling and for the final product

texture. Up to 5–6% moisture content, the wafer

sheets keep their typical crisp texture, but higher

moisture levels will result in most cases in inadequate,

tough, or even soft and soggy textures (see Table 2 for

details).

tbl0002 Table 2 Water activity, water content, and texture of wafers

Wafer condition Wafer texture Water activity, approx. Moisture (%), approx.

Freshly baked Very tender, crisp <0.1 <2

After conditioning Crisp, harder 0.3 4.5

Limit of crispness Crisp to tough 0.5/0.55 6

Wafers, foam-filled Soft to flexible 0.7 12

Collapse of structure Very soft, shrinks >0.85 >20

BISCUITS, COOKIES, AND CRACKERS/Wafers 541

Creaming and Book Building (Figure 2, process 6)

0032 The sheets then pass the creaming station, where a

layer of a sugar- and fat-based cream is applied to one

side. The type of cream flavor liked most varies re-

gionally, but chocolate, vanilla, hazelnut, milk, straw-

berry, and lemon are the most common. Creaming is

done at temperatures of 30–40



C either by contact

spreading or by depositing a preformed cream film.

For flat wafers, several creamed sheets together with

a noncreamed top sheet form a so-called ‘wafer book.’

0033 For hollow wafers, the cream is added to the hollow

parts either by spreading or by controlled single

depositing. Again, either two hollow wafer sheets or

a hollow and a flat sheet are combined to form a

‘book.’

Cooling and Cutting (Figure 2, process 7)

0034 The wafer books pass a cooling tunnel to set the

cream, after which they are wire or saw-cut into

small biscuits.

EnrobingorMoldinginChocolate,Cooling(Figure2,

processes 8 and 9)

0035 The cut biscuits may be enrobed with chocolate-type

coatings, sometimes after the application of chopped

nuts or crispies to the top wafer. Molding in chocolate

is another possibility. After a final cooling step, the

biscuits are ready for packaging.

Packaging (Figure 2, process 10)

0036 The biscuits have to be packed tightly to protect

against humidity, but also against oxygen and light

to prevent oxidative deterioration and to insure a

shelf-life of 6–9 months. Inadequate packaging-film

moisture barriers and bad sealing are the most fre-

quent reasons for later complaints by customers.

Laminated or specially coated films are used for the

typical wafer product packaging in flow packs,

boxes, or bags.

Manufacturing of Molded Wafer Cones

0037 Another type of ‘hollow’ wafers, cones, cups, and

fancy shapes with up to 185 mm in length are pro-

duced in cast-iron molds. Holes for four to six items

are provided in each of these molds, and 12–72 molds

are circulated in one oven. The lower part of the mold

is made of two symmetric halves that open to release

the baked pieces. After their reclosure, they take up a

fresh batter deposit, and finally the ‘core,’ the upper

part of the mold, closes the mold for a new baking

cycle. The baked cones are cooled down and stacked

for packaging.

0038Recipewise, there are two groups of molded cones:

0039No- or low-sugar cones, generally known as ‘cake

cones,’ whose recipes are similar to those for

sheets (see Table 1).

0040The so-called ‘molded sugar cones’ have an inter-

mediate sugar content, usually below 20 parts of

sucrose for 100 parts of flour.

Recent Developments in Molded Wafer Cones

(see Figure 2)

0041Whereas traditionally molded cones have flat tops

and regular, symmetric reedings now for a few years

molds for more sophisticated products can be manu-

factured. We now see cones and cups in the market

showing curvilinear tops and artfully designed out-

sides. Figure 3 shows the first of these, which comes

from a Japanese cone manufacturer.

Manufacturing of Rolled Wafer Cones

(see Figure 4)

0042‘Rolled sugar cones’ need a concentration of more

than 20% of sucrose or other sugars in the finished

product. The first three steps of rolled sugar cone

manufacturing are rather similar to no/low-sugar

wafer sheet baking with the exception of reduced

steam pressure as there are no baking ledges to build

up pressure and to extrude ‘bobbles.’ The deposit is

just to form an oval or circular sheet.

0043Batter preparation (Figure 4, process 1)

0044Batter transport and depositing (Figure 4,

process 2)

fig0003Figure 3 Molded wafer cone: example for new, nonflat top

design.

542 BISCUITS, COOKIES, AND CRACKERS/Wafers

3.0045 Wafer sheet baking (Figure 4, process 3): Now-

adays, equipment is available to manufacture up

to 13000 cones per hour.

0046 Wafer take-off, rolling, and cone release (Figure 4,

process 4): When, after baking, the mold reopens,

the sheet is automatically stripped off the plate and

rolled immediately on tapered mandrels to form

the finished cone. A series of rolling devices

mounted on a round table operates continuously:

Sheet removal, rolling, release, etc.

Glass Transition and Formability

0047 During the rolling procedure, the wafer temperature

is still above the glass transition point. The molten

sugar acts as a plasticizer, and so any rolling or deep-

forming operation can be performed. Besides the

rolled cones, three more types of products are manu-

factured by the same principle:

0048 Wafer ‘rolls’: Wafer sheets of rectangular shape

are baked, stripped off the baking plate, and

rolled into a sugar wafer ‘rod’ without a center

hole (different from wafer ‘sticks’ with a

center hole discussed later). The rod is later cut

into smaller cylindrical pieces. Typically, these

pieces are finally partially enrobed with choc-

olate-type coatings.

0049 ‘Deep-formed’ wafers (cups, shells), where the

hot, flat wafer piece is introduced into a forming

tool, sometimes with an additional embossing or

stamping device, which defines the final shape.

0050Rolled wafer sticks. These are discussed in a

separate chapter below.

Cone Cooling (Figure 4, process 5)

0051The fresh cones pass through a cooling section, where

ambient or cooled air is applied. Here, sugar recrys-

tallization finishes to give the final strong and brittle

texture.

Cone Sleeving and Stacking (Figure 4, process 6)

0052Now, paper sleeves are applied automatically, and

these form the packaging material for the typical end

product, industrially manufactured icecream cones.

Next, is automatic cone stacking and packaging.

0053Later in the icecream plant, the wafer cones are

sprayed inside with chocolate and filled, and finally,

the paper cone is closed.

Manufacturing of Rolled Wafer Sticks

0054Rolled wafer sticks are hollow tubes with walls con-

sisting of very thin multiple layers, similar in texture

to crunchy cereals. These layers do not carry a wafer

pattern and are approximately 0.5mm in thickness.

But from the recipe, the sticks are typical higher-sugar

wafers (see Table 1).

0055In manufacturing, a stripe of batter is applicated to

a heated drum and baked into a continuous wafer

band. The band is rolled immediately while hot into

a continuous still formable tube with an internal

fig0004 Figure 4 Manufacturing line for rolled sugar cones. 1, batter preparation; 2, batter transport and depositing; 3, wafer sheet baking;

4, take-off, rolling and cone release; 5, cooling of cones; 6, cone sleeving, stacking.

BISCUITS, COOKIES, AND CRACKERS/Wafers 543

diameter of about 6–36 mm. From here, there are

several options to create a large family of finished

products:

0056 The tube is automatically cut into wafer stick

pieces and cooled. These are consumed as sweet

snacks or with icecream, for example. Other end

uses include intermediate products for confection-

ers to finish by additional filling or decorating

operations.

0057 During the rolling operation, the tube is coated

inside with compound chocolate or filled with

cream, either partially or fully. Then, cutting and

cooldown, followed optionally by a coating and/

or decorating process, give the finished product.

0058 The filled tube is transformed into small pillow-

like bits by a combined squeezing–cutting oper-

ation.

0059 The wafer tube pieces, nonfilled, coated inside,

or partially cream-filled immediately after cutting

while still hot, pass a pressing station to form oval

or even flat pieces. Such flat pieces may form the

center of premium-type confectionery items with a

chocolate coating, including chopped nuts or

cereal crispies, for example.

0060 Larger-diameter tubes are pressed flat, and by an

embossing and stamping operation, so-called ‘fan

wafers’ or other elaborate shapes can be generated.

The diameter and length of the sticks as well as the

number of very thin, ‘glassy’ sheets forming the wall

of the stick can be adjusted individually. Rolled wafer

sticks have a unique brittle wall texture without being

too hard in biting and chewing.

Savory Wafer Products

0061 Whereas many end uses of wafers in combination with

sweet fillings, coatings, etc. are well known, savory or

neutral-tasting wafer products are becoming increas-

ingly popular in some areas. Some examples:

0062 Wafers as crispbread, delivering a crunchy but

softer texture than traditional hard crisp breads.

Besides wheat flour there are several options for

other cereal and noncereal flours as raw materials.

The products are either neutral in taste to be eaten

with sweet or nonsweet toppings or have spices,

cheese, and other flavorsome ingredients.

0063Wafers – flat or hollow wafers – with savory fill-

ings, e.g., peanut butter or cheese creams.

0064Wafer sticks, a recent development, made from

a nonsweet but still rollable material. These are

typically combined with savory cream fillings.

Trends – From the Very Wafer to a More

Sophisticated End Product

0065After discussing the different wafer types and their

traditional end uses (for an overview, see Table 3), a

sharply increasing number of new confectionery

brand products during the last decade are worth

mentioning. Here, wafers are only a smaller, but still

important, part of the deal. These are small confec-

tionery pieces, mostly in bite-size or sectioned bars,

often chocolate-covered, where the wafer has three

main functions:

0066To add its typical texture and crispness, e.g., to

a soft filling cream with a piece of nut and a

chocolate cover, thus imparting a multitextured

impression.

0067To make the overall product ‘lighter’ in calories

and nutritionally, as the wafer part is of an

extremely low density and cereal-based.

0068To define the precise structure of the piece, e.g.,

when holding a soft filling, or, for noncoated

pieces, to keep the consumer’s hands clean if the

filling melts due to warmer conditions.

Looking to some of the current trends, we see increas-

ing interest in combining lower fat fillings such as

toffee (caramel). Another trend may be newer fat

free fruit-type fillings with water activities that are

so low that the wafers stay crisp. Even some new

examples of fillings with a higher moisture, resulting

in a ‘soft’ wafer part, can be rolled out.

tbl0003 Table 3 Which product from which wafer type?

Endproduct No (low)-sugar wafer Higher-sugar wafer

Wafer crisp bread Flat wafer sheet

Sugar wafer biscuits, creamed Flat wafer sheet

Wafer biscuits, creamed and enrobed or molded

in chocolate

Flat wafer sheet

Containers, e.g., for icecream Molded cake cone Molded sugar cone, rolled sugar cone

Confectionery, filled, enrobed, decorated Hollow wafer or hollow þflat wafer Wafer stick or sugar cone, small

Fan wafers Wafer stick, pressed, embossed

Wafer rolls, partially enrobed Rolled sheet

Wafer bowls Deep-formed sheet

544 BISCUITS, COOKIES, AND CRACKERS/Wafers