Custards, creams & meringues
ermine buttercream
A classic American buttercream made by cooking a paste of flour and milk until it reaches a thick pudding consistency, then beating it into softened butter and sugar. Unlike meringue-based buttercreams, ermine relies on starch gelatinization for body, producing a velvety, less cloying frosting that holds piping work beautifully while remaining notably less sweet.
The formula
1 part flour : 8 parts milk : 10 parts sugar : 10 parts butter (all by weight)
The flour-to-milk ratio (1:8) is non-negotiable; it determines the paste structure that carries the butter. Sugar can range 250–350 g depending on sweetness preference, but 300 g is the classical American bakery standard.
Identity
- A cooked flour paste is the structural skeleton — undercooking produces gummy results
- Butter must be room-temperature (68–70°F / 20–21°C) when incorporated, or the paste will melt it into greasy streaks
- The paste must be fully cooled before meeting the butter, or the butter will liquefy and refuse to emulsify
- Beaten until the texture transforms from dense to light and ribbon-like — this is the creaming action that incorporates air
- No meringue, no Italian syrup — the sweetness comes entirely from granular sugar dissolved into the paste
Ingredients
| Liquid | whole milk | Full-fat milk is essential; lower fat content produces a thinner paste that cannot support the butter |
| Binder | all-purpose flour | Wheat flour contains the starch needed for gelatinization; cake flour works but produces a slightly more tender result, while bread flour yields a slightly firmer paste |
| Base | granulated sugar | Dissolves into the milk during cooking; provides sweetness and contributes to the smooth texture |
| Fat | unsalted butter, preferably European-style (83%+ fat) | European butter's higher fat content produces a silkier emulsion; standard American butter (80% fat) works but yields a slightly more watery result |
| Flavor | pure vanilla extract | One teaspoon is standard; may substitute vanilla bean paste, almond extract (¼ tsp), or omit for neutral applications |
Method
- 1Whisk together sugar, flour, and milk in a heavy-bottomed saucepan until no dry flour remains.Pre-blending prevents lumps from forming when heat is applied; the flour must be fully hydrated before gelatinization begins.
- 2Cook over medium heat, stirring constantly with a wooden spoon or heat-resistant spatula, until the mixture thickens dramatically and begins to bubble gently.Constant stirring prevents scorching on the pan bottom and ensures even heat distribution. Bubbling indicates the starch has fully gelatinized and the mixture has reached a safe temperature.
- 3Continue cooking for 2 additional minutes, stirring without pause, until the paste is glossy and pulls away from the sides of the pan.The brief overcooking completes starch gelatinization and eliminates the raw flour taste that would persist if the paste were used immediately.
- 4Transfer the paste to the bowl of a stand mixer, press plastic wrap directly onto the surface, and cool to room temperature (below 72°F / 22°C).Direct contact with plastic wrap prevents a skin from forming and accelerates cooling. Any warmth will melt the butter when it is added.
- 5With the paddle attachment, beat the softened butter on medium speed until creamy, about 2 minutes.The butter must be already aerated and pliable before the paste is introduced; this establishes the emulsion framework.
- 6Add the cooled flour paste a tablespoon at a time, beating thoroughly between each addition, until all paste is incorporated.Incremental addition allows each portion of paste to emulsify into the butter before the next is added; dumping it all in risks breaking the emulsion.
- 7Continue beating on medium-high speed for 3–5 minutes until the buttercream is light, fluffy, and ribbons off the beater.Extended beating incorporates air and develops the characteristic silky, pipeable texture; this is analogous to creaming butter and sugar.
Techniques that matter
Starch gelatinization
Flour starches absorb water and swell when heated, transforming the milk from a thin liquid into a thick paste that can suspend fat particles
Emulsification
The butter fat exists as discrete droplets coated with starch and sugar; mechanical agitation distributes them uniformly throughout the aqueous phase
Proper temperature management
The butter must be warm enough to cream but cool enough not to melt; the paste must be cool enough not to liquefy the butter — both conditions must be met simultaneously
Variations & derivatives
Chocolate ermineUniversal
Add 85–115 g melted, slightly cooled bittersweet chocolate to the finished buttercream; or whisk 30–40 g Dutch-process cocoa powder into the warm paste before cooling. Both methods produce a rich, satin-smooth chocolate buttercream.
Coffee ermineUniversal
Replace 60 g of the milk with freshly brewed strong coffee; the caffeine does not interfere with the emulsion and adds depth without sweetness.
Crème mousselineFrench pastry
A related but distinct preparation: pastry cream (crème pâtissière) beaten with an equal weight of butter. Uses egg yolks and more sugar in the base, producing a richer, more custardy flavor than ermine.
Used in these dishes
Substitutions
- All-purpose flour → Cake flour — Reduces protein content slightly; produces a marginally more tender paste, but the difference is subtle and the swap is unnecessary
- Whole milk → Heavy cream — Increases fat content excessively; the paste will be too rich and the emulsion unstable — this substitution is not recommendedchanges result
- Unsalted butter → Salted butter (reduce added salt) — Works functionally but adds a flavor element not present in the classical formula; reduce any additional salt to account for the butter's salt content
Troubleshooting
Greasy, broken texture with butter pooling
Paste was too warm when added to butter, or butter was over-softened; heat melted the fat before emulsification occurred → Chill the paste briefly (not in the freezer) until cool to the touch; ensure butter is at exactly 68–70°F; if already broken, gently warm the mixture by setting the bowl over a water bath at 90–95°F while beating slowly, then cool back down
Gummy or paste-like mouthfeel
Insufficient cooking of the flour paste; starches were not fully gelatinized, leaving a raw flour texture → The paste must bubble gently and cook for the full 2 minutes while stirring; if the mistake is caught after frosting, the buttercream cannot be salvaged — discard and remake
Weeping or liquid pooling on frosted cake after sitting
Under-beaten final stage; not enough air incorporated to stabilize the emulsion → Beat the finished buttercream on medium-high for the full 3–5 minutes after all paste is added; if already on the cake, scrape off the weeping layer and reapply a fresh coat