How fats work: shortening, aeration, plasticity and emulsification in baking

Why fat is irreplaceable in the bakery

Flour, water and yeast produce bread. But the moment you want pastry that shatters, a cake that springs back, a croissant that peels into ribbons, or a biscuit that snaps — you need fat. Fat does not simply add richness. It performs four distinct physical and chemical roles that no other ingredient can replicate. Understanding these roles lets you choose the right fat for the job, diagnose failures when they happen, and explain to a customer why you use margarine for one product and butter for another.

This article covers the science, the product data and the practical decision-making, with spec-sheet numbers from seven commercial fat products in the Domson catalogue.

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The four core functions of fat in baking

1. Shortening — interrupting the gluten network

When fat is mixed or rubbed into flour before water is added, the fat coats the protein particles and starch granules. When water later activates gluten formation, the fat-coated surfaces cannot bond fully into long, continuous gluten strands. The result is a shorter, more fragmented network. That is the physical meaning of "shortening": the fat makes the protein network shorter.

The practical consequence: less gluten = less chewiness = tender, crumbly, melt-in-the-mouth textures. This is the defining mechanism in shortcrust pastry, biscuits and scones. Using 50–60% fat on flour weight in shortcrust leaves almost no continuous gluten network, producing the characteristic "short" crumb that breaks cleanly.

The figure below gives a microscopic comparison of unshortened vs fat-shortened gluten.

2. Aeration — entrapping air for mechanical leavening

When solid fat (at approximately 18–22°C) is beaten with sugar, the sharp edges of sugar crystals cut into the fat crystal surface and trap air bubbles. The fat holds those bubbles in suspension. This is the creaming step.

During baking, the trapped air bubbles expand as they heat (Charles's law), and CO2 from baking powder diffuses into them, amplifying the lift. The more air your fat can trap, the finer and more even the crumb. This is why the temperature of the fat at creaming is critical: too warm (above 25°C) and the fat is semi-liquid and cannot trap air; too cold (below 14°C) and the fat is too rigid to deform around sugar crystals and release bubbles.

3. Plasticity — the solid-yet-pliable window

Plasticity describes a fat's ability to behave as a soft, malleable solid across a useful working-temperature range: not so hard that it cracks under stress, not so soft that it flows. This property depends on the balance of solid crystalline fat and liquid oil at each temperature — the Solid Fat Content (SFC).

Most fats are mixtures of many different triglycerides, each with its own melting point. The result is a melting range rather than a single melting point. In this melting range the fat is "plastic" — like modelling clay. The width and position of this range determines what application the fat is suited for.

• Butter has a relatively narrow working-temperature window: approximately 14–22°C is cited in practical lamination guidance.
• Laminating margarines are engineered for a stable plastic range at 16–22°C — matching the bakery working environment.
• Shortenings, with 100% fat and no water, have wide plastic ranges.

The figure below gives SFC curves comparing catalogue products.

4. Emulsification — holding fat and water together

Batter and dough contain both fat and water. Without an emulsifier, these two phases separate: the batter "breaks" (curdles), the crumb becomes greasy and uneven. Fats naturally carry some emulsifying capacity. Butter contains lecithin from the cream. Some margarines and shortenings are enriched with added emulsifiers — typically mono- and diglycerides (E471) or polyglycerol esters (E475/PGMS).

The Cardowan Coronet NHAV HR shortening contains distilled monoglyceride (E471) for exactly this reason: it is a "high ratio" shortening, designed for high-ratio cake formulas where sugar exceeds flour by weight — a batter that would otherwise split without extra emulsification.

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Crystal polymorphism — the hidden architecture

All fats can crystallise in at least three different forms (polymorphs), which differ in how the triglyceride molecules pack together:

• Alpha (α) crystals form on rapid cooling. They are fine and unstable; they quickly convert to beta-prime or beta.
• Beta-prime (β') crystals are fine, smooth and stable at room temperature. They hold air cells well, produce a smooth texture, and are essential for good creaming. Palm oil and most commercial margarines crystallise predominantly in beta-prime form.
• Beta (β) crystals are the most stable thermodynamic form. They are coarser and larger. They give lard and cocoa butter their characteristic waxy, snapping texture. In chocolate they cause bloom (visible white crystals on the surface). In biscuit shortening, beta crystals produce excessive graininess and poor air-holding.

The vast majority of commercial baking margarines and shortenings are engineered to favour beta-prime crystallisation — through the choice of fat base (palm oil is a strong beta-prime former), emulsifiers, and controlled cooling during manufacture.

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Solid Fat Content (SFC) — reading the numbers from spec sheets

SFC is the percentage of fat that is crystalline (solid) at a given temperature. It is measured by NMR spectroscopy or the AOCS Cd 16b-93 pulsed NMR method.

The SFC at key temperatures tells you:

• SFC at 10°C: how firm the fat is when cold (out of the fridge)
• SFC at 20°C: how plastic it is at typical room temperature / lamination working conditions
• SFC at 30°C: how quickly it softens as it approaches body temperature
• SFC at 35–37°C: whether it gives a clean melt-in-the-mouth or a lingering waxy feel

Catalogue SFC data (from spec sheets)

The following values are extracted directly from first-party supplier specifications (see the table below):

Kruszwica Maestra Puff Pastry Margarine 80% (laminating margarine, summer values):

• 20°C: 35–37% — deliberately high to resist absorption into dough during sheeting
• 30°C: 18–23%
• 35°C: 10–13%

The spec distinguishes summer and winter values, acknowledging that the fat source blend changes slightly to maintain consistent functional performance across ambient temperatures. The recommended working temperature is 18–20°C.

CSM Marvello Cake Margarine 80%:

• 10°C: 34% target
• 20°C: 20% target (interval 18–24%)
• 30°C: 12% target (9.5–13.5%)
• 35°C: 9% target (7–11%)

This lower SFC at 20°C compared to the laminating margarine is intentional: a cake margarine at 20°C should be soft enough to cream well with sugar. The SFC above 30°C drops to single digits, delivering a clean finish in the mouth.

Master Martini Marina 80 Solidarity Recipe:

• 10°C: 41–51% (notably high)
• 20°C: 22–32%
• 30°C: 7–17%

The wide ranges for this product indicate it covers multiple seasonal productions or fat blend variations. The high SFC at 10°C and relatively fast drop above 25°C suits a versatile margarine used for both soft-dough applications (yeast pastry) and shortcrust work.

Butter 82% (Polmlek):

• The Polmlek spec confirms fat content (82% minimum) and saturated fatty acids (55 g per 100 g) but does not report SFC values. SFC estimates from reference literature suggest approximately 18–22% at 20°C — but these are single-source estimates (medium reliability) and should not be presented as spec-verified data. The main limitation of butter for lamination is its narrow plasticity range (~14–22°C) and the tendency to either crack at low temperatures or smear at high temperatures.

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Fat types in the Domson catalogue

Butter: 82% fat, the flavour benchmark

Polmlek Unsalted Butter 82% is produced from pasteurized cream and contains no additives or preservatives.

• Fat: 82% minimum
• Water: 16%
• Saturated fatty acids: 55 g per 100 g (67% of fat)
• Energy: 3058 kJ / 744 kcal per 100 g
• Allergen: CONTAINS MILK including lactose
• Storage: 0–10°C (max 60 days); or frozen at -18 to -22°C (max 12 months, consume within 7 days of thawing)

The 16% water content is a functional asset: in puff pastry and croissant, that water flashes to steam during baking and physically separates the dough layers. The milk solids (the remaining ~2%) contribute to Maillard browning, giving butter-based pastry its characteristic deep-gold colour and rich flavour.

The price and allergen implications of butter (MILK) mean many professional bakeries use laminating margarines for volume production, reserving butter for premium retail lines.

Laminating margarines (roll-in fats): engineered for layers

A laminating margarine (also called a roll-in fat, tourage margarine or puff pastry margarine) is engineered to maintain a stable solid-plastic state across the lamination temperature range while melting cleanly at oven temperature.

Kruszwica Maestra Puff Pastry 80%:

• Fat: 80% ±0.5%
• SFC at 20°C: 35–37% (summer) — higher than butter, meaning less risk of smearing at typical bakery temperatures
• Erucic acid (C22:1): max 2.0%, measured by PN-EN ISO 5508 method (this product-specific limit coincides with the current EU contaminant ceiling of 20 g/kg = 2.0% per EU Regulation 2023/915; PN-EN ISO 5508 is the analytical method, not the regulatory text)
• Working temp: 18–20°C
• Ingredients include soya lecithin (E322) — relevant for allergen labelling
• Application: puff pastry, croissants and Danish pastry (ciasta francuskie i półfrancuskie per spec)

The soya lecithin in this product's formulation is declared as an allergen in some markets. Bakers producing for customers with soy allergies should check the full allergen declaration on the current batch spec sheet and consider a lecithin-free alternative.

FLAG — FORMULATION CURRENCY: The Maestra Puff Pastry specification used here dates from 2009 and declares "partially hydrogenated vegetable oils" in its ingredient list. EU Regulation 2019/649 (in force April 2021) limits industrial trans fats to ≤2 g per 100 g fat. Current Kruszwica batches are very likely reformulated without partial hydrogenation; the SFC values and working-temperature recommendations above remain functional parameters relevant to any puff-pastry laminating margarine, but the ingredient list and trans fat content should be confirmed with the current Kruszwica product specification before use.

Cardowan Crown NHAV Pastry Margarine 82%:

• Fat: 82%
• Slip melting point: 47°C
• Saturated FA: 41.2 g per 100 g
• Contains E471 (distilled monoglyceride) but no soya lecithin
• No allergens in product, line or factory
• RSPO certified (Segregated & Mass Balance, cert BMT-RSPO-000023)

The 47°C slip melting point for this pastry margarine means it maintains its solid state well into the oven cycle, holding the layer structure while the dough sets. No allergens in product or factory makes it suitable for allergen-controlled production environments.

Cake and cream margarines

CSM Marvello Cake Margarine 80%:

• Fat: 80%, Saturates: 27 g/100g (lower saturate profile than pastry types)
• Trans fat: 0.9 g per 100 g product (non-animal derived; equivalent to approximately 1.1 g per 100 g fat — within EU Regulation 2019/649 limit of ≤2 g per 100 g fat)
• SFC at 20°C: 20% target (18–24%)
• Moisture: 15–20%
• Kosher and Halal certified (confirm current certification status with CSM before customer-facing publication — certifications require periodic renewal)
• No allergens in product or on production line (wheat present in factory only)
• Storage: 14–18°C

Marvello's lower saturate profile (34% of fat, vs 50%+ for pastry margarines) and its SFC optimised for creaming at 20°C make it well-suited for industrial cake production. Its kosher and halal certifications expand its customer reach considerably.

Kruszwica Milama Cake & Cookie Margarine 80%:

• Fat: 80%, SAFA 41%, MUFA 45%, PUFA 13%
• Trans fat: max 2% (typical value) — Food safety: the Milama spec dates from December 2020, before EU Regulation 2019/649 came into force April 2021; the declared "max 2% typical" value sits at the regulatory ceiling of 2 g per 100 g fat.
• SFC at 20°C: 20–25%; SFC at 35°C: max 5% (clean finish)
• Allergens: absent from product and cross-contact (both confirmed absent in spec)
• Application: cakes and cookies

Master Martini Marina 80 Solidarity Recipe:

• Fat: 80%, saturates 39 g/100g
• Trans FA: max 1.0%
• SFC at 20°C: 22–32% — a wider SFC range suggesting broader application latitude
• pH of water phase: 4.60 ± 0.25 (acid water phase reduces microbial risk)
• Application: shortcrust, yeast doughs, puff pastry — a versatile product
• May contain traces of milk (cross-contact, ZK* declaration in spec)

Vegetable shortenings: 100% fat, maximum plasticity

Shortenings contain no water: 100% fat, 0% moisture.

Cardowan Coronet NHAV HR Shortening 12.5 kg — the HR (High Ratio) designation signals that this product contains E471 (distilled monoglyceride):

• Fat: 100%; saturates 38.1 g; MUFA 43.5 g; PUFA 16.2 g
• Energy: 3700 kJ / 900 kcal per 100 g
• Slip melting point: 44°C
• Air content: 12% — pre-incorporated air facilitates high-ratio cake aeration
• FFA: 0.10%; peroxide value: 1.0 meq O2/kg (very fresh, low oxidation)
• No allergens in product, production line or factory
• RSPO certified (NHAV = No Hydrogenation, No Animal ingredients, No Vegan concerns)

Cardowan Plain Box NHAV Shortening 12.5 kg — no E471 emulsifier:

• Fat: 100%; saturates 38.8 g; MUFA 43.5 g; PUFA 15.5 g
• Slip melting point: 45°C; air content: 12%
• No allergens; RSPO certified

The absence of E471 in the Plain Box product means it works best in standard (non-high-ratio) applications: bread enrichment, general pastry work, doughnut frying. For high-ratio cakes (sugar > flour), the Coronet HR with E471 is the correct choice.

The NHAV designation used by Cardowan confirms these products are suitable for halal and vegan customers.

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The science of laminated doughs

How layers form

Lamination is the process of alternately folding fat between sheets of dough to create hundreds of discrete layers. The dough provides structure (gluten and starch); the fat provides the barrier that prevents adjacent layers from merging; and the water within the fat (or dough moisture) provides steam that physically pushes the layers apart during baking.

The figure below shows a laminated dough cross-section, illustrating how steam from the fat layers separates the dough into flaky layers during baking.

Puff pastry: up to 729 layers, achieved with six single folds (3^6 = 729); other fold combinations are used in practice (BAKERpedia cites a range of 81–729 layers). No yeast. All lift comes from steam. The butter or laminating margarine accounts for approximately 50% of the total dough weight.

Croissant: 27 layers when three single folds are used (3^3 = 27); other fold configurations are common, with layer counts typically ranging from 24 to over 100 depending on technique. Yeast present. Lift from yeast CO2 combined with steam.

Danish pastry: similar to croissant but further enriched with egg and sugar; fewer lamination folds (lower layer count) for a more open crumb.

The temperature window

This is where most lamination failures occur. The fat must remain as a solid, cohesive sheet throughout sheeting — not crack, not smear.

The Maestra spec is explicit: the recommended fat temperature for production is 18–20°C. If the bakery runs warm, chill the fat for 15 minutes before laminating.

Margarines have a wider plasticity range than butter. This is a deliberate engineering choice: the SFC at 20°C for Maestra (35–37%) is higher than typical butter (~18–22% est.), meaning margarine is more forgiving of small temperature fluctuations. However, margarines will not deliver the flavour of butter, and discerning customers will notice the difference in a premium product.

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Dosage by application

See the table below for full dosage ranges. In summary:

All dosage values are reference ranges from BAKERpedia, the LibreTexts Canadian Baker open textbook and IREKS Compendium.

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Frying fats

Frying fats require different selection criteria than baking fats:

Smoke point is the temperature at which a fat begins to degrade visibly, producing acrolein (toxic, acrid-smelling) and other breakdown products. At the smoke point, the fat begins to impart off-flavours and is unsafe for continued use. Palm frying oil has a naturally high smoke point due to its high saturated fat content; vegetable shortenings follow a similar pattern.

Free Fatty Acid (FFA) content is the primary indicator of frying fat quality. Fresh fat FFA should be ≤0.10% (confirmed in both Cardowan shortening spec sheets ). As fat is used, FFA rises due to hydrolysis from steam and food moisture. Replace or discard frying fat when FFA exceeds 0.5–1.0%, or when the oil darkens significantly.

Peroxide value measures oxidation (rancidity development). Fresh fats should be ≤1.0 meq O2/kg; the Cardowan specs confirm this as their typical value. Above 2–3 meq O2/kg, off-flavours become detectable.

The Domson catalogue includes Palm Frying Oil 25 L. Palm oil's high saturated fat content (~50%) makes it resistant to oxidation at frying temperatures, giving it a long frying life compared to polyunsaturated oils such as sunflower.

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Sustainability and palm oil

Palm oil appears as a primary ingredient in most of the margarines and shortenings in this catalogue. It is the world's highest-yielding oil crop (5–10× more oil per hectare than rapeseed or sunflower), but its expansion into tropical regions has been linked to deforestation and biodiversity loss.

The main industry response is the Roundtable on Sustainable Palm Oil (RSPO). Both Cardowan products in this catalogue carry RSPO supply-chain certification (Segregated & Mass Balance, certification BMT-RSPO-000023). Food safety: RSPO certifications are audited annually and can lapse; verify current certification status against the RSPO certificate database (rspo.org) before making sustainability claims in customer-facing material.

RSPO supply chain models:

• Segregated (SG): only RSPO-certified palm oil in the supply chain, kept separate from conventional palm
• Mass Balance (MB): RSPO-certified volumes tracked through the supply chain but physically mixed with conventional

The Maestra Puff Pastry 80% is available in a Mass Balance RSPO certified variant (Maestra Puff Pastry Mass Balance, movex 515 104).

Palm-free reformulation is technically possible using shea, illipe, kokum, high-oleic sunflower or interesterified rapeseed, but achieves different functional properties (often lower SFC at 20°C, different crystal form, narrower plasticity range). The Qualita NP Palm-Free Margarine in the Domson catalogue offers a palm-free option where required.

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Allergen summary

Allergen declarations are from supplier spec sheets. Cross-contact risk depends on shared lines and production schedules which can change. Always obtain the current batch spec sheet from the supplier before making allergen claims to customers.

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Practical fat selection guide

The flowchart below gives a visual version of this decision guide.

Is your product laminated (croissant, Danish, puff)? Use a laminating margarine with SFC at 20°C of 30–40% (e.g. Maestra Puff Pastry, Crown NHAV Pastry, Mimetic 32, Plus Croissant Margarine, Flex Quatro Danish) or a tourage butter if premium flavour is required. Never use a cake margarine: its low SFC at 20°C means it will smear into the dough.

Is your product a cream-aerated cake or sponge? Use a cake margarine or butter with SFC at 20°C of 18–25% and good beta-prime crystal structure. Temperature at creaming is critical: 18–22°C. Choose a kosher/halal-certified option (e.g. CSM Marvello) where required.

Is your product a biscuit or shortcrust pastry? Shortening, butter or margarine will all work. Lard produces exceptional flakiness in shortcrust. Butter gives superior flavour. Shortening gives the widest plastic range and no dairy allergen.

Is your product fried? Use a dedicated frying oil or palm shortening. Select on smoke point and oxidative stability. Monitor FFA and peroxide value in-use.

Is your product an enriched bread or soft roll? Add 2–10% shortening or cake margarine to the dough. Fat is added after initial gluten development to avoid coating proteins before the network forms.

Do you need to avoid dairy? All Cardowan NHAV shortenings and margarines are dairy-free with no allergens in the factory. CSM Marvello contains no dairy in product or production line. Check full spec sheets for cross-contact risk.

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Formula reference

Three reference formulas are provided below:

• formula-croissant: Classic croissant baker's percentage with laminating fat
• formula-shortcrust: All-purpose shortcrust pastry with fat dosage
• formula-pound-cake: Classic pound cake / Victoria sponge creaming method

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Fault diagnosis

See the table below for the full ten-fault cause-remedy table. Key principles:

• Tough pastry = too little fat, or fat melted too early (gluten formed freely before fat could coat proteins)
• Flat puff pastry = fat temperature wrong (smeared in or cracked during lamination)
• Dense cake = fat too warm or too cold at creaming (no air entrapment)
• Rancid flavour = fat oxidation (check peroxide value; rotate stock; verify storage conditions)

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Coverage notes and research gaps

Solid: SFC data from seven first-party spec sheets (Kruszwica, Cardowan, CSM, Master Martini). Crystal polymorphism mechanism from BAKERpedia, high reliability. Allergen declarations from spec sheets. Layer counts for laminated doughs from BAKERpedia: puff pastry "up to 729 layers" (six-fold; BAKERpedia states range 81–729) and croissant "27 layers" (three single folds; BAKERpedia states range 24–144 layers) are reference values for specific fold configurations. Sustainability (RSPO) from a Bakels insight article and spec sheet provenance declarations; RSPO certification status requires current independent verification.

Single-source / medium confidence (cannot be externally cross-checked — all spec values are private documents with no public URL):

• Butter SFC and plasticity range (working-temperature estimates from Pastry Arts Magazine and BAKERpedia only; Polmlek spec does not report SFC; the cited sources do not explicitly define a plasticity range)
• Butter melting point (~32–35°C) is widely cited in food science literature but the specific reference (Pastry Arts Magazine) may not directly contain this value — use a primary food-science source for any published claim
• Smoke point of palm frying oil — not read from spec (no Palm Frying Oil 25 L spec sheet available in catalogue)

Follow-up needed:

• Read spec sheet for Palm Frying Oil 25 L when available (smoke point, FFA spec, fatty acid profile)
• Obtain current spec for Tourage Croissant Butter 10 kg and Mimetic 32 Lamination Fat to add SFC values
• Confirm soya allergen status on Maestra with current batch documents (some spec sheets indicate traces of milk cross-contact; this article has reported what the 2009 specification stated)
• Full country-by-country regulatory position on trans fat labelling (EU Regulation 2019/649 limits industrial trans fats to ≤2 g per 100 g fat — Marvello at 0.9 g and Milama at <2% are within the limit; Marina at max 1.0% is within limit) — recommend regulatory review before publishing trans fat values