Pastry creams & cold fillings

Cold fillings are the quiet workhorses of a patisserie. A croissant, an éclair, a fruit tart, a layer cake and an entremet can all share one base cream — crème pâtissière — and differ only in what you fold in afterwards. Get the base right and the rest of the menu follows. Get it wrong and you get weeping tarts, grainy éclairs, collapsing cakes and, worst of all, a microbiological risk in an egg-and-dairy product. This dossier covers the whole cold-filling toolkit: the crème pâtissière family, ganache, and stable fruit curds — and the handful of numbers that decide whether they work.

See img-creme-pat-process for the core cooking sequence and img-cream-family-tree for how the derivatives branch off the base.

1. Crème pâtissière — the base cream

Crème pâtissière is milk thickened by both starch and egg yolk, cooked to a boil. A representative professional ratio is, per 1 litre of whole milk: 8 egg yolks, 200–250 g sugar, approximately 60–100 g cornflour (home recipes often 50–65 g; patisserie/commercial ratios up to 100 g for a firmer, more pipeable custard; or substitute ~90 g custard powder) [c33]. Whole milk matters — lower-fat milk gives a gummier, weaker cream [c33]. The full bench formula is in formula-creme-patissiere.

The single most important step: boil it

Two things happen when you bring pastry cream to a full boil and hold it for 1–2 minutes:

1. The starch fully gelatinises, trapping water and thickening the cream.
2. The alpha-amylase enzyme naturally present in egg yolk is deactivated — it dies somewhere between ~80°C (176°F) and boiling [c34].

If you stop heating as soon as it thickens, the amylase survives. Overnight it keeps cleaving the starch you just gelatinised, and your beautiful pastry cream turns soup-thin in the fridge [c34]. This is the classic "it was fine last night" failure. The fix is in the method, not the recipe: boil it. After cooking, pass it through a sieve, spread it thin, film-wrap on contact, and chill rapidly to below 4°C (see food safety, §6) [c40]. img-faults-diagnosis shows this and the other common defects.

Starch choice

Cornflour (maize starch) gives a clean, glossy, sliceable cream; flour gives a more "old-fashioned" opaque set; potato starch is common in industrial mixes. For products that will be frozen and thawed, native starch weeps on thawing — use a modified/waxy starch (most ready mixes already do). The catalogue native maize starch (AGRANA Maisita, moisture ≤14%, neutral-paste viscosity ≥330 BU at 95°C) is the workhorse cook-out thickener [c29].

The scale alternative: cold-process custards

For volume production, egg-free consistency and a long dry shelf life, cold-set custard mixes skip the cooking entirely. Zeelandia Roma Cold Classic and Roma Cold Patisserie reconstitute at 1000 g powder to 2500–3000 g cold water, whisked on 2nd/3rd speed, and must be held below 5°C once made [c10][c13]. They gel cold using modified potato starch (E1414) plus alginate and phosphate gelling agents [c11]. Powder cream bases (Zeelandia Delice Patissière, 400 g : 1000 g cold water [c1]; CSM Craigmillar Creme Pat, 400 g : 1 L [c5]; Emix custard, 400 g : 1 L [c8]) sit between scratch and ready-to-use. img-cold-vs-cooked-process compares the routes; the headline numbers are in table-catalogue-key-numbers.

2. The crème pâtissière family

Everything in table-cream-family starts from the cooked base. What you add changes the texture and the stability:

• Crème légère — pastry cream + whipped cream, no gelatine. Lightest, but soft; use the same day.
• Crème diplomat — pastry cream stabilised with gelatine, then lightened with whipped cream. This is the modern pastry chef's default for cakes and tarts because it is light and sliceable. Use roughly 20% whipped cream / 80% pastry cream for firm piping, up to 40% whipped cream for an airier choux filling [c35]. Formula: formula-creme-diplomat.
• Crème mousseline — pastry cream beaten with soft unsalted butter, typically 50% of the pastry-cream weight or more (equal weight of butter to cream is common in classic recipes; do not go below 50% or the cream will not set firmly) [c36]. Rich, firm when chilled, the classic fraisier and Paris-Brest cream. The one rule: butter and cream must be the same cool temperature or it splits. Formula: formula-creme-mousseline.
• Crème chiboust — pastry cream + Italian meringue (+ gelatine); the Saint-Honoré cream.

Ready filling creams (Puratos Cremfil Silk 2.0 / Puracrem 2.0, Emix custard, Zeelandia Delice) give a diplomat-like result with less labour; many can be enriched with butter or folded with whipped cream the same way a scratch base would be [c8].

3. Setting & stabilising: starch vs gelatine vs agar

The choice of setting system is a technical and a dietary/commercial decision (see table-gelling-systems and img-gelling-agents-temperature-scale).

Gelatine

Gelatine dissolves in warm liquid (the catalogue Bowika porcine grade dissolves below 40°C and gels on cooling at 20–37°C, forming a clear gel) [c15]. It melts at body temperature (~35°C) — which is exactly why gelatine-set creams "melt in the mouth" [c22]. Two handling rules decide success:

• Bloom first. Soak leaf gelatine in cold water 5–10 minutes and squeeze; hydrate powder in about 5× its weight of cold water (the 1:5 "gelatine mass") [c20].
• Never boil it. Gelatine loses setting power above ~100°C [c20]. Dissolve the bloomed gelatine into a warm (not boiling) portion of the cream.

Grades are sold by Bloom strength, and — counter-intuitively — sheet weights are adjusted so that one sheet of any grade is roughly interchangeable by count (table-gelatin-grades, img-gelatin-bloom-grades): titanium ~100 Bloom/5.0 g, bronze ~125/3.3 g, silver ~160/2.5 g, gold ~200/2.0 g, platinum ~250/1.7 g [c18]. The catalogue Kluman Bronze leaf is 140 Bloom (125–155) [c17]; powder (Knox-type) is ~200–225 Bloom and one ~7 g sachet ≈ 3 sheets [c19]. A typical use level to set a cream is ~1.5–2% of the liquid [c20].

Important: gelatine here is porcine — both the Bowika and Kluman products are pig-derived and are therefore not halal, not kosher, and not vegetarian/vegan [c16][c17]. For the platform's Muslim, Jewish and vegetarian customers this is decisive; reach for agar instead.

Agar (the vegan, heat-stable alternative)

Agar (E406, from red algae) behaves almost oppositely to gelatine: it only hydrates near boiling (~85–95°C, ~5 min), sets high (gel point 37 ± 5°C), and only re-melts again near 85°C — so it is heat-stable and survives transport and gentle baking [c21][c22]. It gives a firmer, more brittle gel; typical dosage is 0.2–3% (soft gels 0.2–0.5%) [c22]. The catalogue Hortimex Agar MN5 has a gel strength ≥850 g/cm² [c21]. One trap shared with gelatine: raw pineapple, kiwi and ginger enzymes will stop gelatine setting (heat the fruit first, or use agar) [c22].

Cream stabilisers

Whipped-cream fillings collapse without help. Gelatine-based stabilisers do the work in one step: Zeelandia Zeesan is dosed at 200 g + 250 g water folded into 1000 g whipped unsweetened cream, then set in the fridge for at least 1 hour [c32]. Emix EmiFOND is the equivalent. Remember whipping cream itself needs ≥30% fat to whip and ≥36% for firm stiff peaks (UK double cream is ~48%) [c39]; the catalogue OSM Bieruń Double Cream is a 33% UHT cream-and-vegetable-fat blend [c30].

4. Ganache

Ganache is the exception in this dossier: it is not pastry-cream-based — it is an emulsion of chocolate and cream, set by cocoa butter, and tuned entirely by the ratio (by weight, never volume) (table-ganache-ratios, img-ganache-ratio-chart, formula-ganache):

• Dark: 1:1 chocolate:cream for a glaze/soft filling; 2:1 for a firm filling or truffle [c37].
• Milk: 1.5:1 to 2:1 [c37].
• White: 2:1 to 3:1 [c37].

Milk and white need less cream because their higher sugar and milk-solids content already softens the set [c37]. Whipped ganache is simply a lighter-ratio ganache, set cold then whipped to a pipeable mousse.

Use couverture, not compound coating: by EU Directive 2000/36/EC, couverture must contain ≥35% total dry cocoa solids including ≥31% cocoa butter [c38] — that cocoa-butter level is what gives ganache a clean set and gloss. Catalogue bases include Barima dark 72% (≥43% fat, ≤1% moisture) [c23], and Callebaut 811 dark 54.5% / 823 milk 33.6% / W2 white 28% [c42]. For speed, Martin Braun Chococover is a ready ganache sauce (45% dark chocolate, aw ≤0.80): melt at 38–40°C to coat, or whip 30–50% into whipped cream for a filling [c25][c26]. For the crystallisation and bloom side of chocolate, see the sibling dossiers A6-chocolate-selection-couverture and A6-chocolate-tempering-crystallisation.

5. Stable fruit curds & fruit fillings

A fruit curd is a custard with fruit acid: eggs (and butter) thicken it, while the low pH and high sugar act as natural preservatives. Cook a scratch curd gently to ~77°C (170–175°F) until it coats a spoon, then mount with cold butter; refrigerated, it keeps roughly 1–2 weeks (culinary sources cite 1 week to ~10 days) [c41] (formula-lemon-curd). For scaled or bake-stable work, ready fillings remove the food-safety and consistency risk: Puratos Deli Citron is a bake-stable lemon filling at Brix 69.5–73.5%, pH 3.10–3.50, water activity 0.79–0.83, with a 9-month shelf life [c27][c28]. Note its allergens — it contains MILK and sulphites (E223) — and that it is halal-certified but not vegan [c28]. Water activity below ~0.85 plus low pH is what makes these fillings shelf-stable where a fresh pastry cream is not.

6. Food safety, allergens & shelf life (flag for review)

Cold fillings are high-risk: egg, dairy, sugar, water — ideal for bacteria. The non-negotiables [c40]:

• Cool fast and hold cold. Chill freshly cooked cream quickly (spread thin, film on contact) and store at or below 4°C.
• Mind the danger zone. Never leave egg-based cream more than 2 hours in the 4–60°C range (note: the 2-hour limit and 4°C lower bound follow US FDA guidance; UK FSA guidance uses 8°C as the practical lower bound for chilled foods — confirm the applicable national food safety authority's rules before publication) [c40].
• Short life. Scratch pastry cream keeps 3–4 days refrigerated; discard at any off smell or texture.
• Prefer pasteurised eggs and dairy to limit Salmonella risk.

Allergens to declare (from the catalogue specs): MILK is present in essentially every cream here; soya (lecithin) in chocolate [c24]; sulphites (E223) in Deli Citron [c28]; and cross-contamination warnings for gluten, egg and soya on several mixes [c4][c12]. Gelatine is porcine in both catalogue products — critical for halal/kosher/vegetarian customers [c16][c17]. Dry shelf lives from the specs: cream powders 6–12 months; chocolate 24 months; gelatine ~5 years; agar 36 months; UHT cream 4 months chilled.

Additional flags requiring human review before publication: (1) Zeelandia Zeesan cream stabiliser is gelatine-based, but the gelatine species (porcine, bovine, or fish) is not confirmed on the available spec sheet — buyers serving halal, kosher or vegetarian customers must obtain confirmation of species directly from Zeelandia before declaring dietary suitability [c32]. (2) OSM Bieruń 'Double Cream' UHT is 33% fat; under UK The Cream Regulations 1995 the 'double cream' designation is reserved for products with ≥48% milk fat — use a compliant product name (e.g. 'UHT whipping cream blend 33%') when supplying UK B2B customers to avoid misleading labelling [c30]. (3) Halal certification on Puratos Deli Citron does not name the certifying body on the available TDS — for B2B use with Muslim customers the certifying body and certificate number should be obtained from Puratos [c28]. All food-safety, allergen and dietary statements above are flagged for human review before publication.

7. Buying guide — what a baker actually orders

• Crème pâtissière from scratch: whole milk, egg yolks, caster sugar, AGRANA Maisita maize starch, vanilla.
• Crème pâtissière / diplomat without cooking: Zeelandia Delice Patissière, CSM Craigmillar Creme Pat, Emix custard powders; Zeelandia Roma Cold mixes for fully cold-set; Puratos Cremfil/Puracrem ready creams.
• Stabilising whipped cream / diplomat: Zeelandia Zeesan or Emix EmiFOND; gold/bronze gelatine (Bowika, Kluman) or agar (Hortimex) for vegan/halal/kosher and heat-stable work.
• Ganache: Barima 72% or Callebaut 811/823/W2 couverture + double/whipping cream (OSM Bieruń, Master Martini Decor Up); Martin Braun Chococover for a ready sauce.
• Fruit curds: Puratos Deli Citron (bake-stable, long-life) or scratch lemon curd.
• Praline/nut creams: Martin Braun Nuss-Plus as a mousseline enrichment.

The full numeric comparison is in table-catalogue-key-numbers; faults and fixes in faults-pastry-cream.