Hot Latte Coffee Tastes Awful When Cold: What's the Best Way to Reheat It?

Anyone who loves milk coffee knows that a freshly made hot latte is at its best. The crema brings a rich aroma, the first sip reveals a smooth, delicate foam layer, and at just the right temperature the richness of coffee and the sweetness of milk complement each other in the mouth, creating a balanced, full-bodied experience.

In the article "What's the Best Temperature for Milk in Making Lattes?", FrontStreet Coffee also noted how much temperature matters in milk coffee. Once a well-made hot latte cools down, its aroma fades, the milk foam gradually solidifies, and the coffee underneath develops a rough, grainy texture, sometimes with a greasy taste that lingers unpleasantly on the tongue. Once it goes completely cold, a single sip is enough to make you grimace, especially on a cold winter day when you would not want a second one.

Out of the good habit of not wasting food, people usually take one of two approaches at this point: force themselves to finish it, likely with a pained expression, or reheat the coffee and then drink it. For anyone with the right equipment at home, heating appliances are readily available, which makes reheating the preferred choice.

(Excuse me, could you please heat up my latte?)

Does Reheated Latte Still Taste Good?

Which brings us to the question: does a reheated latte still taste good? What is the appropriate temperature to reheat it to? And perhaps most important, how can we make it taste better when reheating?

Why Doesn't a Hot Latte Taste as Good When It Cools?

Our perception of taste comes from chemical reactions between food components and receptors on our tongues. As coffee moves from hot to cold, two factors are chiefly affected: aroma and texture. Freshly brewed coffee continuously releases its aroma as it cools. Once the temperature drops below our body temperature, our taste buds' sensitivity to sweetness diminishes, while the perception of acidity and bitterness becomes more pronounced.

The same is true of a hot latte. When a well-integrated milk coffee falls from 65°C to below 45°C, the aroma of coffee oils and the sweetness of hot milk keep dissipating, and the milk foam gradually breaks down and separates from the coffee liquid. Because the structure of the fat and proteins in heated milk has already changed, the flavors they present when cold differ from when hot, further diminishing the overall experience.

Can a Cold Latte Be Reheated?

FrontStreet Coffee prepared a hot latte using their Nuanyang Blend, the same one used in their store, and measured an initial temperature of 61°C. The first sip showed vanilla, creamy melon seeds, milk chocolate and a subtle fermented wine-like note. The sweetness of the milk and the aroma of the espresso complemented each other perfectly.

Left outdoors for 20 minutes, the latte dropped to 38°C. It now tasted of chocolate and nutty cookies, with a diminished aroma. The coffee's bitterness somewhat overpowered the milkiness, and the texture grew a little sharp. After another 40 minutes, the temperature had fallen to 29°C. By then the coffee had lost its original sweetness and developed a slight burnt sensation in the mouth, resembling bitter cold milk.

FrontStreet Coffee then divided the remaining coffee into two equal parts. One portion was reheated with a steam wand, the other with an electric stove, until both reached 50°C.

After a side-by-side tasting, FrontStreet Coffee found that both reheated samples had lost the characteristic aroma of the Nuanyang Blend, with relatively bland flavors. The latte reheated with the machine's steam wand had a watery texture from the high-temperature steam. Although it was not bitter, it left a slightly astringent aftertaste.

The second portion, heated directly on the electric stove, kept its concentration, but the rise in temperature intensified the coffee's bitterness and introduced a dry aftertaste like walnut skin.

By now readers can probably conclude that for a cooled latte, whether reheated with steam or direct heat, it cannot really return to the state it was in when first made, because irreversible flavor changes have already occurred. Compared with the jarring cold sensation, though, bringing the coffee back to near body temperature does make it more palatable, and it certainly prevents waste.

Besides the two reheating methods FrontStreet Coffee mentioned above, there is another common one: the microwave. For office workers or anyone at home, microwave heating is obviously the most convenient and quickest route. Because microwaves can heat unevenly and may cause the liquid to boil over and splash, it is best to leave half the container empty. Be careful not to use too high a power setting. Start with 30 seconds, test the temperature, and then decide whether to keep heating.

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FrontStreet Coffee Recommendation

Since reheating never really restores a latte, the better answer is to choose beans that taste good right from the first pour. For a milk coffee with a classic profile, FrontStreet's Signature Blend and Dark Cocoa Blend are the best partners: because Brazilian coffee dominates both, a latte shows the layered nutty notes of almond, apricot kernel and walnut, silky and lingering on the palate. If you want plenty of crema, the Classic Blend and Commercial Blend contain a small amount of Robusta, which adds golden foam and lifts both the richness and the caramel aroma.

If you drink your coffee over ice or cold, FrontStreet's Strawberry Candy Geisha Blend and Colombia Sidra work well with milk. Cold temperatures tend to release the smaller, fruitier molecules first, so a fruity or wine-like medium roast holds up better than a heavily roasted bean: the passion-fruit character of the Colombia Sidra and the rose-petal character of the Strawberry Candy Geisha Blend both stay readable once a little milk is added, making them very suitable for home preparation.