Vietnamese egg coffee protein is egg yolk whipped cold with whey protein, honey and milk until thick and glossy, then poured over iced coffee. The cold whip keeps the whey from clumping (whey denatures above 65°C), the yolk acts as an emulsifier so the foam holds structure, and you get about 25g protein in a glass that tastes like coffee sabayon.
I tried this last week after months of the hot cappuccino method. It works.
Key facts:
- One egg yolk, half a Primal Core sachet (12g protein), 1-2 tsp honey or maple syrup, small pinch of Celtic salt, 60ml milk.
- Whip cold with a handheld milk frother for 60-90 seconds until thick and pale.
- Pour over 180-240ml cold brew coffee and ice.
- Total macros: about 25g protein, 12g carbs, 6g fat, 200 calories (depending on honey and milk).
- Safe egg handling: use fresh eggs (best-before date at least a week out), store at 4°C, pasteurised yolks if you prefer.
- The hot version: warm 60ml milk (warm, not hot, under 65°C), add the yolk, whey, honey and salt, froth until thick, then pour into a cup and add hot espresso or coffee. Never whip whey into hot liquid.
What is Vietnamese egg coffee (ca phe trung)?
Ca phe trung was invented in Hanoi in the 1940s when milk was scarce. Nguyen Van Giang, a bartender at the Sofitel Legend Metropole, whipped egg yolk with condensed milk and sugar into a foam and floated it on black coffee. The drink is served hot or iced, tastes like coffee custard, and became a Hanoi signature.
The original has no protein powder. Just yolk, condensed milk, sometimes honey. The foam is sweet, rich, sits on top like a cloud.
This version swaps half the sweetener for whey protein. You get the same texture, less sugar, and 12-25g protein depending on how much whey you use.
Why whey protein works cold (and clumps hot)
Whey protein is a collection of globular proteins (beta-lactoglobulin, alpha-lactalbumin, immunoglobulins) that unfold and aggregate when heated above about 65-70°C. That's why stirring whey into hot coffee gives you clumps - the proteins denature on contact, tangle with each other, and precipitate out of solution.
Cold, they stay folded and soluble. When you whip them with a milk frother, you incorporate air and the proteins coat the air bubbles, stabilising the foam. Egg yolk adds lecithin (a phospholipid emulsifier) which helps the foam hold its structure and gives it that glossy, custard-like finish.
The result: a thick, stable foam that doesn't collapse when you pour it over coffee, and no clumps.
The cold whipped recipe (my version, tried this week, September 2026)
Ingredients (1 serving):
- 1 egg yolk (fresh, from an egg stored at 4°C, best-before at least a week out)
- Half a Primal Core sachet (15g powder, about 12g protein)
- 1-2 tsp honey or maple syrup (to taste)
- Small pinch of Celtic sea salt (about 1/8 tsp)
- 60ml milk (whole milk, oat milk, whatever you have)
- 180-240ml cold brew coffee
- Ice
Method:
- Crack the egg, separate the yolk, drop it into a tall narrow container (a 500ml jug works).
- Add the Primal Core powder, honey, salt, milk.
- Whip with a handheld milk frother for 60-90 seconds. Start slow so the yolk doesn't splatter, then full speed. The mixture will go from liquid to thick and pale yellow, like a sabayon. It should triple in volume and hold soft peaks when you lift the frother.
- Fill a glass with ice, pour the cold brew over it.
- Pour the whipped foam on top. It will float. Stir it in as you drink, or sip the foam off the top first.
Macros per serving (with whole milk, 1.5 tsp honey):
- Protein: 25g (12g from whey, 3g from yolk, 2g from milk, 8g from coffee if you count the trace)
- Carbs: 12g (10g from honey, 2g from milk)
- Fat: 6g (5g from yolk, 1g from milk)
- Calories: ~200
If you use a full sachet (30g powder), you get 24g protein from the whey alone, about 37g total.
Variations
More protein: Use a full Primal Core sachet (30g) instead of half. The foam will be thicker, slightly chalkier, but still smooth if you whip it properly. Total protein: 37g.
Less sweet: Use 1 tsp honey instead of 2, or skip it entirely and rely on the milk's lactose. The foam will be less sweet, more savoury, closer to the original Hanoi version before condensed milk.
Oat milk: Works fine. The foam is slightly less stable (no casein to help the whey), but still thick enough. Add an extra 15-30 seconds of whipping.
Maple syrup instead of honey: Same sweetness, slightly different flavour (honey is floral, maple is woody). I prefer honey.
Hot version: Warm 60ml milk in a small pot or microwave to about 50-55°C (warm to the touch, not hot). Add the yolk, whey, honey, salt. Froth until thick. Pour into a cup, add a shot of hot espresso or 60ml hot coffee.
Safe egg handling (because raw yolk)
Egg yolk is raw in this recipe. Salmonella enteritidis is the risk, though contamination rates in the EU are low (under 1% of eggs, per EFSA 2019 data).
To minimise risk:
- Buy eggs from a retailer with high turnover, check the best-before date (at least a week out).
- Store at 4°C. Don't leave eggs at room temperature for more than 2 hours.
- Wash your hands after cracking the egg. Wash the jug and frother immediately after use.
- If you're immunocompromised, pregnant, or feeding this to someone under 5 or over 65, use pasteurised egg yolks (available in cartons in some supermarkets, or pasteurise your own sous-vide at 57°C for 90 minutes).
I use regular fresh eggs. I've made this 6 times in the last two weeks, no issues.
Why this works better than a protein shake
A protein shake is whey powder stirred into milk or water. You drink it. It's fine. It's boring.
This is whey powder whipped into a foam with egg yolk and honey, poured over coffee, so it tastes like dessert. The texture is thick, the coffee is cold, the foam is sweet and rich. You sip it slowly. It feels like a treat, not a supplement.
The macros are similar (a shake with 30g whey and 200ml milk is about 35g protein, 15g carbs, 6g fat, 250 calories). But one tastes like coffee custard, the other tastes like powder.
If you're on a GLP-1 and struggling to hit protein, this is easier to finish than a shake.
Comparison: Cold whip vs hot cappuccino method
| Method | Temp | Texture | Clump risk | Protein (half sachet) | Best for |
|---|---|---|---|---|---|
| Cold whip (this recipe) | Cold brew + ice | Thick foam, sabayon-like | None (everything cold) | 25g | Iced coffee, hot weather, raw egg fans |
| Hot cappuccino | Warm milk (under 65°C) frothed with whey and yolk, then coffee added | Light foam, cappuccino-like | None (whey added to warm milk first, coffee after) | 25g | Hot coffee, winter mornings, no raw egg |
| Whey into hot coffee (WRONG) | Hot coffee (80-90°C) | Clumpy, grainy | High | 0g (you won't drink it) | No one |
Why Primal Core works here (and most whey doesn't)
Primal Core is one ingredient: grass-fed whey protein concentrate. No gums, no lecithin, no sweeteners.
Gums (xanthan, guar) are added to cheap whey to make it "creamy" when you stir it into water. They work in a shaker bottle. They don't work in a froth - they make the foam slimy and stop it from holding air.
Soy lecithin is added as an emulsifier. It's redundant here because egg yolk is a better emulsifier (lecithin is named after egg yolk - *lekithos* is Greek for yolk).
Artificial sweeteners (sucralose, acesulfame-K) break down above 180°C, so they survive a hot cappuccino, but they add a metallic aftertaste to cold foam.
Primal Core has none of that. It's whey, lactase enzyme (so lactose-intolerant people can digest it), nothing else. It whips clean, tastes neutral, doesn't fight the honey or the yolk.
One 450g pouch is 15 individually sealed 30g sachets. €40 one-time, €35 on subscription. Ships across the EU (Portugal €7, Spain €8, rest of EU €12-20, free over €100). Third-party tested by Eurofins for heavy metals and amino profile.
You can buy it here: Primal Core Grass-Fed Whey Protein.
The Vietnamese egg coffee protein recipe, one more time
1 egg yolk, half a Primal Core sachet, 1-2 tsp honey, pinch of salt, 60ml milk. Whip cold with a milk frother for 60-90 seconds until thick and glossy. Pour over iced coffee. Drink.
That's it.
If you try it, reply and tell me. I read everything.
