Ingredients
What each ingredient does, mechanically — including the things it stops from happening.
Ingredient pages here are organised around function rather than description. “Sugar sweetens” is a description; “sugar competes with flour for water, which slows gluten development and keeps the crumb tender” is a function — and only the second lets you reason about what happens if you reduce it.
Ingredients
Wheat flour
Milled wheat endosperm, and the only common flour whose proteins form gluten in the way baking depends on.
Flours and grainsBread flour
Wheat flour milled from higher-protein wheat and sold for doughs that need to hold gas through a long fermentation.
Flours and grainsWater
The ingredient every other reaction in baking depends on, and the one whose quantity most strongly determines how a dough behaves.
LiquidsButter
A fat with a significant water content and a melting range near room temperature, which is why it can both shorten and laminate.
FatsEggs
An ingredient performing at least four unrelated functions, which is why substituting for them is rarely straightforward.
EggsSugar
Sweetener, tenderiser, browning agent, moisture-holder and aeration aid — most of which have nothing to do with taste.
Sugars and syrupsYeast
A single-celled fungus that ferments sugars to carbon dioxide and ethanol, providing both lift and a large part of bread’s flavour.
Leavening agentsBaking powder
A complete chemical leavening system: bicarbonate of soda, one or more acids, and a starch to keep them apart until wetted.
Leavening agentsBicarbonate of soda
A single alkaline compound that releases carbon dioxide when it meets an acid — and leaves a soapy residue when it does not.
Leavening agentsSalt
A seasoning that is also a fermentation regulator and, by professional consensus, a modifier of gluten behaviour.
Salt and mineralsAquafaba
The viscous water from cooked or canned chickpeas, which whips into a foam resembling egg white — with performance that varies substantially between brands.
Functional additivesGround flaxseed
Milled linseed which forms a mucilaginous gel with water — a capable binder that supplies no aeration and no structure whatever.
Functional additivesApple purée
A moisture-and-sugar replacement often recommended for eggs, which replaces the water an egg contributed and none of its other functions.
Functional additivesCommercial egg replacer
A formulated blend, usually starch and raising agents, engineered for one or two of egg’s functions and honest about which.
Functional additivesXanthan gum
A bacterial fermentation gum used in very small quantities to thicken and hold gas — and the ingredient most often wrongly described as replacing gluten.
Functional additivesPsyllium husk
A soluble fibre that forms a strong gel with water, giving gluten-free dough something closer to handleable elasticity — at a measured cost in crumb gumminess.
Functional additivesGuar gum
A seed-derived thickener that works mainly by raising viscosity and binding water, and which behaves differently enough from xanthan to matter.
Functional additivesRice flour
The most common base of gluten-free blends: neutral in flavour, low in protein, and the source of the gritty texture gluten-free baking is known for.
Flours and grainsTapioca starch
A pure starch from cassava that adds chew, stretch and browning to gluten-free bakes, and structure to none of them.
Flours and grainsPotato starch
A light, fast-gelatinising starch that softens gluten-free crumb — and which is emphatically not potato flour.
Flours and grainsAlmond flour
Ground almonds: high in fat and protein, containing no starch at all, and therefore behaving unlike every other flour in this section.
Flours and grainsOat flour
Milled oats — a soft, mild flour whose gluten-free status depends entirely on how it was handled, not on what it is.
Flours and grainsGluten-free flour blend
A formulated mixture whose contents vary widely between brands — which is why one recipe behaves differently with different bags of it.
Flours and grainsBrown sugar
Sucrose carrying molasses — which makes it acidic, hygroscopic and chemically different from white sugar, not merely darker.
Sugars and syrupsCaster sugar
White sugar milled fine — the same chemistry as granulated, and a different result wherever dissolving speed matters.
Sugars and syrupsIcing sugar
Sugar milled to a powder and cut with starch — which is why it dissolves instantly and why it is not a drop-in replacement by weight.
Sugars and syrupsButtermilk
An acidic cultured milk whose value in baking is its acid — which is why the common substitutions work and why they are not identical.
DairyShortening
Solid fat that is essentially all fat — no water, a high melting point, and behaviour no butter can quite reproduce.
FatsSalt types and measuring
Table, sea, kosher and flaky salt are chemically near-identical — and a spoonful of each is a different weight, which is where recipes go wrong.
Salt and mineralsEgg white
Water and protein, no fat — which makes it the only part that whips to a stable foam and the part that toughens if overused.
EggsEgg yolk
Fat, emulsifiers and colour — the part that enriches and tenderises, and the part that cannot set a structure on its own.
EggsCocoa powder
A dry, acidic, starch-poor powder that behaves like a very thirsty flour — and whose pH decides which leavener a recipe needs.
FlavouringsMilk
The default liquid of enriched doughs and most cake batters — water with protein, sugar, fat and minerals dissolved and suspended in it, each of which changes the bake.
DairyDouble cream
Milk fat concentrated to the point where the fat, not the water, governs the behaviour — which is why it whips and why it is a poor substitute for milk.
DairyNatural yoghurt
Cultured milk bringing acid, body and liquid at once — the acid being the part that changes the chemistry rather than only the taste.
DairyHoney
A concentrated sugar syrup that is hygroscopic, acidic and browns early — three reasons it is not a drop-in replacement for sugar.
Sugars and syrupsBread improver
A blend, not a substance — usually an oxidant, an enzyme, an emulsifier and a carrier, sold together to make dough behave predictably at scale.
Functional additivesEmulsifiers in bread
Additives that strengthen dough and soften crumb by interacting with starch — the reason a supermarket loaf is still soft on day five.
Functional additivesEnzymes in baking
Biological catalysts that do what fermentation time and chemical improvers used to — increasingly the industry’s preferred route because they leave no additive on the label.
Functional additivesSour cream
Cultured cream — acid, fat and liquid together — which is why it tenderises more aggressively than yoghurt and enriches where yoghurt lightens.
DairyEvaporated milk
Milk with much of its water removed and nothing added — which makes it concentrated milk, and makes it categorically different from condensed milk.
DairyPlant milks
Soy, oat, almond and the rest — and a measured finding that in at least one product they behaved far more like dairy milk than the usual advice suggests.
LiquidsVegan block butter
Plant-based fat sold in a block to be used like butter — and whether it behaves like butter depends almost entirely on how much water it carries.
FatsChia seed
Forms a mucilage gel in water that binds — and, like flax, supplies none of the aeration or coagulating protein an egg brings.
Functional additivesCornflour
Pure maize starch — the reference thickener, and in baking a diluent that removes protein from a flour rather than adding anything to it.
Flours and grainsArrowroot
A root starch that sets clearer and softer than cornflour and tolerates acid better — and breaks down if held at heat.
Flours and grainsCoconut flour
Defatted, dried coconut ground fine — extremely high in fibre, extraordinarily absorbent, and the least substitutable flour in ordinary use.
Flours and grainsMargarine
A category rather than a substance — plant fat and water emulsified to imitate butter, and how well it imitates butter depends almost entirely on the ratio.
FatsSelf-raising flour
Plain flour with raising agent already blended in — convenient, and the reason it goes wrong is that the leavening is on a clock you cannot see.
Flours and grainsCake flour
A very soft, low-protein, finely milled flour — and in Britain largely a concept rather than a product on the shelf.
Flours and grainsWholemeal flour
The whole grain milled together — and the bran that makes it wholemeal competes for the water the gluten needs.
Flours and grainsRye flour
Almost no functional gluten and a great deal of pentosan gum — which is why rye dough behaves like nothing else and why rye bread is acidified.
Flours and grainsGranulated sugar
The default sugar, and coarser than caster — which matters wherever the sugar has to dissolve or trap air.
Sugars and syrupsDemerara sugar
Large, hard, pale-brown crystals that do not dissolve readily — which makes it a topping sugar rather than a baking sugar.
Sugars and syrupsGolden syrup
An inverted sugar syrup — which is why it resists crystallising, holds moisture, and makes flapjacks chewy rather than sandy.
Sugars and syrupsBlack treacle
The dark, bitter, strongly acidic end of the syrup range — and the acidity is what makes it react with bicarbonate of soda.
Sugars and syrupsVegetable oil
A category, not a substance: any neutral liquid oil sold for cooking. Liquid at every temperature a kitchen reaches, which decides almost everything it can and cannot do.
FatsOlive oil
A liquid oil chosen for flavour rather than for function — which makes the grade question a flavour question, not a baking-performance one.
FatsCoconut oil
The fat that is a different ingredient depending on the room. Solid on a cool worktop, liquid on a warm one, and it is not a butter substitute in either state.
FatsLard
Rendered pork fat: plastic over a usefully wide range, essentially water-free, and the traditional pastry fat for reasons that survive scrutiny.
FatsGhee and clarified butter
Butter with the water and milk solids taken out — which removes two of the four things butter was doing and concentrates the third.
FatsSpelt flour
An ancient wheat that does form gluten — and forms it differently enough that dough made with it behaves like wheat dough on a shorter timer.
Flours and grainsSemolina
Coarsely milled durum wheat. The particle size is the point, and it is why semolina cannot simply be swapped for flour.
Flours and grainsCream of tartar
An acid powder that does two unrelated jobs — half of a baking powder, and the stabiliser that makes an egg-white foam forgiving.
Leavening agentsMaple syrup
A liquid sugar that is mostly sucrose and mostly water — so substituting it for granulated sugar changes the hydration before it changes the sweetness.
Sugars and syrupsCondensed milk
Milk with most of its water removed and a very large quantity of sugar added — which makes it a sweetener with a dairy component rather than a milk.
DairyFresh yeast
The same organism as the dried forms, sold alive and wet — which changes how much you weigh out, how long it keeps, and almost nothing else.
Leavening agentsItalian 00 flour
A grade of milling fineness, not a protein specification — which is why '00 flour' on its own tells you almost nothing about how a dough will behave.
Flours and grainsMuscovado sugar
Unrefined cane sugar with its molasses never removed — darker, wetter, more acidic and more strongly flavoured than the soft brown sugar it is shelved beside.
Sugars and syrupsGlucose syrup and corn syrup
Starch broken down into a syrup that resists crystallising — bought for what it stops happening rather than for sweetness.
Sugars and syrups
What ingredients do
The functions below are the join between otherwise unrelated ingredients. Eggs, milk solids and sugar all contribute to browning by different routes, and understanding browning as a function is what makes a substitution reasonable rather than a guess.
Structure building
Proteins and starches form the framework a bake stands up in. Wheat proteins hydrate and are worked into an elastic gluten network; egg proteins coagulate on heating into a firm set; starch granules absorb water and swell, then gel. Which of the three dominates is one of the most useful ways to classify a product.
StructureVolumeCrumb texture
Binding
A binder is something viscous or gel-forming that coats and bridges the solid particles in a mixture, so the mass holds together under handling and through baking. Egg does this through its proteins; hydrocolloids such as the mucilage in ground flaxseed or chia do it by forming a gel with water. Binding says nothing about whether the result will rise or hold an open crumb, which is why a good binder can still make a dense bake.
StructureHandlingCrumb texture
Glazing
A glaze is applied to the surface immediately before baking and works only there. Protein and sugar in the glaze brown faster than the bare surface would, and the film left behind reflects light, producing shine. This is the one egg function with a genuinely close non-egg substitute — milk, cream and plant milks all brown a surface — because it does not require any of egg’s structural behaviour.
BrowningCrust
Gluten inhibition
Fat coats flour particles and interposes itself between protein strands, so the continuous network cannot form. Sugar competes with protein for available water, slowing hydration and therefore development. Both produce tenderness by subtraction, which is why cake and pastry formulations often look like bread formulations with the structure deliberately sabotaged.
TendernessStructureHandling
Aeration
Gas reaches a bake by four routes: beaten in mechanically as air, produced biologically by yeast fermentation, produced chemically by a leavener releasing carbon dioxide, or generated physically as water turns to steam. Most products use more than one. Crucially, chemical and biological leaveners mostly expand cells that already exist rather than creating new ones — which is why creaming and whisking matter even in a chemically leavened batter.
VolumeCrumb textureStructure
Gas retention
Gas produced by fermentation or by a chemical leavener has to be held in place while the bake sets, or it migrates, coalesces and escapes. Retention needs a continuous phase that resists flow — either a cohesive, extensible film such as a developed gluten network, or a sufficiently viscous batter, or a gel formed by a hydrocolloid. Which of the three is doing the work is one of the sharpest ways to tell one baking system from another. Note that retention and aeration fail differently: a bake short of aeration was never light, while a bake short of retention rose and then lost it.
VolumeCrumb textureStructure
Hydration
Water dissolves salt and sugar, allows starch to gelatinise, permits gluten to form, provides the medium for fermentation and enzyme activity, and turns to steam as a leavening gas. Almost nothing in baking happens without it, and the amount present relative to flour — the hydration — is the single most influential number in bread.
StructureCrumb textureHandlingMoisture
Browning contribution
Two distinct reactions are usually both at work. Maillard browning requires reducing sugars and amino groups from proteins together, and produces most of the savoury complexity in a crust. Caramelisation requires only sugar at sufficient temperature. Ingredients that supply protein alongside sugar — eggs, milk, milk powder — accelerate crust colour far more than sugar alone.
BrowningCrustFlavour
Fermentation substrate
Yeast cannot metabolise starch directly. Enzymes present in flour break starch down into simpler sugars, which yeast then ferments to carbon dioxide and ethanol. This is why a lean dough with no added sugar still ferments perfectly well, and why flour’s own enzyme activity is a real variable in bread quality rather than a technicality.
VolumeFlavourCrumb texture
Moisture retention
Sugars, syrups and some fats bind water and slow its migration and loss. The effect is on perceived freshness rather than on staling itself: staling is driven largely by starch retrogradation, a structural change that proceeds even when water content is unchanged. An ingredient can make a stale crumb feel less dry without making it less stale.
MoistureShelf lifeTenderness
pH modification
An acid is required for bicarbonate of soda to release carbon dioxide, which is why one appears in every formulation using it alone. pH also affects browning rate — alkaline conditions accelerate Maillard browning — and influences the colour of some pigments, which is why alkalised cocoa is darker than natural cocoa.
VolumeBrowningFlavour
Emulsification
Emulsifiers carry both water-attracting and fat-attracting regions, so they sit at the boundary between the two and stop droplets merging. Egg yolk is the classic natural example, owing largely to its lecithin content. A stable emulsion in a cake batter gives a finer, more even crumb, because the fat stays dispersed rather than pooling.
Crumb textureStructureMoisture
Flavour contribution
Some ingredients taste of something on their own. Others contribute almost no flavour directly but enable reactions that produce a great deal — flour’s own enzyme activity during a long fermentation is the clearest example. Salt belongs in a third category: it contributes its own taste and simultaneously changes the perception of other flavours.
Flavour