Why −86°C Ice Cup Dirty Coffee Is the Hottest Specialty Coffee Trend Right Now

 The first time I tried a Dirty coffee served in an ultra-low-temperature ice cup was back in 2023, at UNCLE SHU Coffee in Binjiang, Hangzhou. It was my first real encounter with that striking “hot-meets-cold” contrast, and the experience left a strong impression.

Dirty coffee is something most coffee lovers in China are already familiar with. It’s fairly common in cafés across Asia, yet you’ll rarely find it in Europe or the U.S. At its core, a Dirty is simple: ice-cold milk topped with hot espresso. This collision of temperatures creates a dramatic, almost theatrical drinking experience that many people love.

In recent years, however, a new trend has taken things to the extreme—using ice cups chilled to −86°C to make Dirty coffee. Compared with a traditional Dirty, which usually uses milk and a cup chilled to around 4°C, a −86°C ice cup paired with espresso at roughly 65–70°C creates a temperature difference of more than 150°C. This extreme contrast delivers a sharper, more intense sensory experience and a longer-lasting cold sensation that ordinary Dirty coffees simply can’t achieve.

One unique result of this method is the formation of a thin layer of “milk frost.” When cold milk is poured into an ultra-frozen cup, a delicate layer of frozen milk instantly forms along the inner wall of the cup. Visually, you’ll often see white vapor rising from the glass, which adds a strong sense of drama. In terms of texture, it introduces an extra layer of enjoyment—you can even scoop up this milk frost with a spoon after finishing the coffee.

The −86°C cup also functions as a powerful “cold reservoir.” Even in the peak of summer, it can keep a Dirty coffee cold for a remarkably long time, significantly slowing down the warming of both the milk and the espresso. Every sip stays refreshingly cold. From a presentation standpoint, this method is also a win. Many customers are quite obsessed with the layered look of a Dirty coffee, and the extremely cold cup helps preserve that separation. The cold cup walls lock in the espresso’s crema and slow the mixing of coffee and milk, allowing the layers to remain visible for much longer.

There’s also a clear marketing angle to all of this. Cafés often highlight the number “−86°C” very prominently. It sounds extreme, memorable, and instantly sparks curiosity. Seeing such a number alone is enough to make people want to try it. Many customers even film the entire process—from baristas wearing gloves and using tongs to retrieve the cup, to explanations of how to drink it quickly. This ritualized presentation not only enhances the sense of occasion, but also strongly encourages social sharing.

That said, I couldn’t help but wonder: why −86°C specifically? What would happen at other temperatures?

After looking into it, the differences become clearer. A standard frozen cup is usually kept at around −18°C, the typical temperature of a home freezer. This is already a common and effective method for Dirty coffee—it increases the temperature contrast, extends the cold sensation, and helps maintain layering. A chilled cup, stored in a refrigerator at about 4°C, can also be used. In this case, the cup temperature matches that of the cold milk, creating clear layers and a noticeable hot-cold contrast, but the cooling effect is short-lived. After about five minutes, the drink begins to approach room temperature. Finally, there’s the room-temperature cup option. While not ideal, it’s still workable—especially at home when you’re just making a casual daily cup. The layering can still look decent, but the hot-cold contrast is much weaker, and the milk warms up very quickly. If you don’t drink it fast, the flavors blend too much and the experience suffers.

Interestingly, many professional baristas point out that −86°C isn’t a strict or precise requirement. Rather, it represents the lowest stable temperature that commercial deep freezers can reliably reach. In real-world café operations, frequent opening and closing of the freezer means the cup temperature often fluctuates between −60°C and −86°C. As long as the cup is cold enough to create milk frost and provide extreme cooling, the core experience remains intact.

For those who haven’t tried this style of Dirty yet, there’s one concern worth addressing: it won’t freeze or damage your mouth. Once the hot espresso and cold milk are poured in, the liquid temperature is actually well above 0°C. What you’re really experiencing isn’t danger—it’s contrast, precision, and a carefully crafted sensory spectacle.

Protein Coffee: Benefits, Risks, and How to Drink It Correctly for Weight Loss

 Coffee and protein powder—perfectly normal on their own. But when you mix them together, things start to feel… a little strange. Still, for people who want both energy and nutrition, “protein coffee” has become the ultimate hybrid drink.

By blending coffee with protein powder or ready-to-drink protein shakes, this viral combo promises three major benefits: energy + protein + weight control. With all these buffs stacked together, it quickly took over social media.

But is this trendy drink really as magical as people claim? Who should drink it—and how do you drink it correctly?
Let’s break down protein coffee from a scientific perspective so you can avoid mistakes and maximize benefits.

1. First Things First: Why Do People Drink Protein Coffee in the Morning?

Protein coffee became popular because the “energy boost of coffee” perfectly matches the “nutritional benefits of protein,” especially for busy individuals.

1. Protein at Breakfast: Controls Appetite + Protects Muscle

Protein is the body’s “building material.” It maintains muscle mass, strengthens immunity, and is extremely helpful during fat-loss phases.

Registered dietitian Tara Collingwood notes:
“Consuming 20–30 grams of protein at breakfast significantly increases satiety and reduces hunger and overeating throughout the day.”

Studies also show that morning protein helps improve body composition, increases lean mass, and prevents muscle loss during weight reduction—one of the biggest reasons fitness enthusiasts swear by protein coffee.

2. Liquid Protein + Coffee = Convenient and Easy to Absorb

Compared with eggs or chicken breast, protein coffee offers advantages in liquid form:

• Faster digestion and absorption

• Easy to track protein intake

• Less chance of overeating

For busy workers or students, one cup of protein coffee covers both energy and protein, saving time without sacrificing nutrition.

3. The Caffeine Bonus: Energy + Digestion Support

Caffeine wakes you up and stimulates digestive enzyme secretion, helping the body use protein more efficiently.

However:

• Decaf versions offer protein only, not energy

• There’s no scientific proof that coffee + protein creates “super synergy”—they’re mostly complementary

  

2. How to Make It: 3 Ways + Expert-Recommended Recipes

Protein coffee is easy to make at home and highly customizable.

1. Basic Version: Protein Powder + Coffee (The Lazy Favorite)

Add one scoop of whey protein (about 13g protein) into brewed black coffee.
Fast, precise, and ideal for fitness-focused individuals.

2. Easy Version: Ready-to-Drink Protein + Coffee (No Clumps!)

Collingwood especially recommends pre-made protein beverages:
“They mix better than protein powder and give a smoother mouthfeel.”

Mix coffee and protein drink at a 1:1 ratio and shake. Perfect for those who care about texture.

3. Creative Version: Protein Coffee Smoothie (More Nutritious)

NYC nutritionist Jackie Newgent shares her upgraded recipe:
Blend cold brew + plant milk + 1 scoop protein powder + cocoa powder + half a banana + a spoon of nut butter.

Rich flavor, high protein, added fiber and healthy fats—great as a breakfast replacement.

3. Important Risks: 4 Mistakes You Must Avoid

Protein coffee isn’t for everyone. Drinking it incorrectly can backfire.

1. Too Much Protein: Kidney Strain

Long-term excessive protein intake (recommended: 10%–35% of daily calories) can strain the kidneys, especially for people at high risk for kidney disease.

Experts emphasize:
“Unless you’re an athlete with very high energy expenditure, protein powder is not a daily necessity.”

2. Too Much Caffeine: Palpitations & Insomnia

Adults should stay under 400 mg caffeine/day—about 4–5 cups of coffee.

If you already consumed tea or energy drinks, reduce your coffee dose.
Pregnant women, heart patients, and caffeine-sensitive individuals should choose decaf or avoid it altogether.

3. Relying on Protein Powder Alone: It’s Not Real Food

Many protein powders are highly processed and cannot replace natural protein sources like:

• Eggs (protein + lecithin)

• Milk (calcium + vitamin D)

• Soy products (fiber)

Protein coffee should be a supplement, not a long-term breakfast replacement.

4. Adding Sugar and Cream: Turns It Into a High-Calorie Bomb

Adding sugar, cream, or creamer can turn your “healthy drink” into a calorie overload.

Best choice: black coffee + unsweetened protein powder
If needed, add a splash of milk or a zero-calorie sweetener.

4. Who Should Drink It—and Who Should Avoid It?

✔ Best For

• Busy workers or students who want quick breakfast protein

• People in fat-loss or fitness phases

• Coffee drinkers who want a more nutritious morning routine

✘ Should Avoid or Be Cautious

• Kidney patients or high-risk individuals

• Pregnant or breastfeeding women

• People sensitive to caffeine or with heart issues

• People who can already get enough protein from natural foods

In short, protein coffee is a functional drink—the key is drinking it based on your needs. If it helps you stay healthy and efficient, it’s a good choice. If you’re just following a trend, it might do more harm than good.

The Secret Behind Clear Coffee: How CLR CFF Made Coffee Completely Transparent

 Do you still remember CLR CFF, the colorless, crystal-clear coffee that went viral nearly a decade ago? I was lucky enough to actually try that “internet-famous” product back then. For so long, we all believed coffee could be reddish-brown, brown, or even red—but it never crossed our minds that coffee could exist as something completely transparent.

When CLR CFF was first released, it immediately caught the attention of coffee lovers. It became the world’s first colorless coffee drink, and its production process was always described in a vague, mysterious way—“made with methods never used before.” It sounded almost mythical, and no one ever seemed to crack the secret behind it. Today, the brand’s social media accounts have gone silent, its official website is no longer maintained, and similar products have essentially vanished. So how did they manage to make coffee completely clear? Let’s talk about this “mysterious” technology.

Simply put, the core idea is to keep the flavor and caffeine of the coffee while removing all substances that create color. The key technology behind this result is precise separation and recombination. Just like traditional coffee, the process starts with carefully selected beans that are roasted—usually lightly roasted to achieve a bright, fruity acidity while avoiding the heavy color and oils produced by dark roasts. Next comes the extraction stage, which is crucial for transparent coffee.

Cold brew is typically used to extract this type of colorless coffee. Using hot water would pull out more oils, acidic components, and suspended solids from the beans—substances that cause cloudiness and dark color. Cold brewing, on the other hand, gently extracts the volatile aroma compounds and caffeine while minimizing the release of pigments and oils. This means the initial coffee liquid is already much lighter in color compared to hot-brewed coffee.

The cold-brew concentrate then undergoes the second key step: a series of highly precise filtration processes. First comes ultrafiltration, which removes large molecules such as proteins, polysaccharides, and some pigments. Next is nanofiltration, capable of filtering out even smaller molecules, including most of the components responsible for color. After these two steps, the liquid undergoes reverse osmosis, which removes nearly everything except water molecules and the very smallest compounds. This process functions like a molecular-level sieve, leaving behind clear water, caffeine, and the aroma compounds that define flavor.

I remember that when I tasted this transparent coffee, if I had been blindfolded, I wouldn’t have known it wasn’t regular coffee. It had a refined and surprisingly full flavor, balanced and very similar to a typical cold brew. But with such extensive filtration, some volatile aroma compounds inevitably get lost. To solve this, manufacturers may use a technique similar to aroma recovery. During the early stages of extraction, they capture those volatile aromas and then reintroduce them back into the filtered, colorless liquid to ensure the final product still smells like coffee.

Finally, the processed clear coffee liquid, the recovered aromas, and any necessary components (possibly tiny amounts of natural flavorings to enhance taste) are blended and bottled. With all solids and oils removed, transparent coffee typically has very low acidity and an extremely clean, smooth mouthfeel. It was advertised as a zero-calorie or low-calorie beverage, and for people worried about coffee staining their teeth, its colorless nature made it stain-free. The refreshing taste also made it easy to mix with cocktails or sparkling water for unique “coffee-based” drinks—coffee flavor without coffee color, which naturally generated tons of buzz.

However, transparent coffee does have drawbacks. Its flavor is extremely simple—smooth and balanced, but thin, almost like “water with coffee flavor.” It’s also a highly processed beverage, much like how some people feel hesitant about decaf, believing it loses the soul of coffee and many of its natural qualities. But the biggest reason we rarely see CLR CFF or similar products today is the cost. The production process is extremely complex and expensive. Back in 2017, a 200 ml bottle of CLR CFF cost me nearly 80 RMB including shipping—far more expensive than a regular cup of coffee with a richer, more complex flavor.

Overall, I see CLR CFF as a fascinating achievement in food engineering—a product made through cold brew extraction, molecular-level filtration, and aroma management. But it was never destined to disrupt traditional coffee or become mainstream. Its disappearance from the market seems almost inevitable. In reality, products built on viral hype often become temporary trends. What truly stands the test of time are the simple, everyday coffees that people return to again and again.

The Viral Edible Coffee Cup Trend Taking Over China’s Cafés

 A new “edible coffee cup” has quietly gone viral across social platforms, becoming a must-try item for young consumers. On Xiaohongshu alone, over 38,000 users have posted about it, and total views have reached nearly 10 million—and the number keeps climbing.

So, what exactly is an edible coffee cup? It’s an innovative concept emerging from the specialty-coffee scene: a cookie-like cup made from oat flour and other grains, baked into shape and coated with a layer of chocolate on the inside to prevent leakage. The cup can hold coffee for more than 30 minutes, making it fully functional while also fun and delicious. With both novelty and practicality, it perfectly hits consumers’ curiosity and has sparked a trend across multiple cities in China.

ACOC Specialty Coffee in Chongqing is one of the first to ride this wave, and its signature drink, the Black Sesame Vienna, has become a viral sensation. Served in a crispy oat-cookie cup and topped with fluffy black-sesame cream, the drink delivers both rich coffee flavor and satisfying crunch. On its small-program menu, the drink is priced at 38 RMB—far from cheap—but customer enthusiasm remains sky-high. Many who tried it shared: “Queued for over an hour,” “The shop is packed during the day—go in the evening instead,” showing just how hot the product has become.

Hugh Cafe, a neighborhood coffee shop in Chengdu, quickly followed the trend and released three limited-edition edible-cup drinks: Christmas Wreath Latte, Pistachio Matcha Christmas Fantasy Cup, and Burning Cloud Cocoa. Unlike standard edible cups, these versions feature extra candy, pistachio crumbles, or marshmallow garnish on the rim, creating an even stronger visual impact. Prices range from 39 to 45 RMB. At one point, the Christmas Wreath Latte sold out completely—not due to a shortage of coffee, but because the edible cups themselves ran out, forcing the brand to rush new batches overnight.

As the trend spreads, more cafés are adopting edible cups as their new traffic boosters. According to incomplete stats, cafés in Wuxi (Youshi Coffee), Hefei (FUMU Manor Cafe), and Baoji (Liangguozi Coffee) have all launched similar products with impressive sales results. Wuxi Youshi Coffee even stated, “We can’t keep up with the orders.” The Hefei shop sold out on the same day it launched. Liangguozi Coffee announced online: “Edible cups are sold out—the next batch is in production.”

However, it’s worth noting that edible-cup drinks are currently offered only for dine-in or in-store pickup, with no delivery option. Hugh Cafe and ACOC both explained: “Delivery would ruin the presentation,” and “There is no suitable delivery packaging—it must be consumed on the spot.” Industry insiders believe this limitation may prevent edible cups from being scaled across large coffee chains.

Still, it’s undeniable that the “drink it, then eat it” experience—combined with high visual appeal and social-media value—perfectly aligns with young consumers’ demand for upgraded, experience-driven spending. This creative fusion of dessert and beverage may well become the next major trend in the specialty-coffee industry.

Still Tired After Coffee? Try the Office Trend: the “Coffee Nap”

 Every morning in office buildings you’ll see coworkers clutching a cup of coffee — like they can’t function without it. But things have flipped: some Silicon Valley folks are actually using coffee to help them nap.

As life speeds up, more young people have joined the “I’m exhausted, coffee is my steel” club. Over time, many develop a kind of caffeine immunity: they can drink coffee in the afternoon or evening and still fall asleep at night.

Now cue concerned relatives and a chorus of wellness accounts: “Just take a nap! Napping is better than coffee!” True — a short nap is a proven way to shake off sleepiness. But what if you combine coffee and a nap? Turns out, that combo can work even better.

How Caffeine Keeps You Awake

Caffeine wakes you up by blocking adenosine, a chemical in the body that promotes sleep. Adenosine binds to receptors in the brain and reduces neuron activity, which makes you feel drowsy. Because caffeine’s molecule looks similar to adenosine, it can bind to those same receptors and prevent adenosine from doing its job — in effect removing the brake on your neurons and making you feel alert.

Caffeine Also Boosts Your Mood

Some adenosine receptors are linked to dopamine receptors. Dopamine helps us feel good. When adenosine occupies those receptors, dopamine can’t get in. But when caffeine binds there instead, dopamine has a chance to act — which lifts your mood.

The Coffee Nap Works Best for Restoring Energy

What is a “coffee nap”?

If you haven’t tried a coffee nap, just do it — don’t be shy. This method has scientific backing: it can boost your productivity and improve the quality of your rest. The “perfect” coffee nap has some specifics. Studies show 200–250 mg of caffeine is ideal — roughly the caffeine in a single pour-over made with about 15 g of coffee beans.

Coffee is better for this than soda. After you drink coffee it stays in your stomach for a bit, and then the small intestine absorbs the caffeine and distributes it through your body. It takes about 20 minutes for caffeine to affect your brain — and that delay is your cue to nap. If you fall asleep quickly after drinking the coffee and wake up when the caffeine kicks in, the result is fantastic. So drink your coffee quickly, don’t sip it slowly. A cup of pour-over or a glass of cold brew will do — drift off to sleep with the aroma of coffee, then wake up feeling refreshed and in a great mood.

How to time it

Set an alarm for 20–30 minutes, then nap. Some people feel pressured by a time limit and can’t fall asleep — that’s okay. Research shows that even if you don’t fully fall asleep, a 20-minute period of drowsy, semi-sleep rest still helps. But don’t nap longer than 30 minutes: if you enter deep sleep and wake up mid-cycle, you’ll feel groggier than before.

When to do it

Coffee naps are best during the day, especially between 1:00 and 3:00 PM. Caffeine’s half-life — the time it takes for half the caffeine to clear from your body — is about 3–5 hours, so doing a coffee nap too late can disrupt nighttime sleep and leave you staring at the ceiling. If you’re caffeine-tolerant and want both the alertness and the taste of coffee, try a coffee nap before you start an intense afternoon work session — you might be pleasantly surprised.

Final notes

A coffee nap is a great short-term energy booster and can make up for a little lost rest, but the best solution is still consistent, sufficient nighttime sleep. During seasons or moments when you always feel sleepy — spring lethargy, autumn fatigue, summer naps, or those sluggish winter months — plain coffee sometimes just won’t cut it. Take one more step: give the coffee nap a try.