Slate coffee is a solid choice if you’re looking for a high-protein, low-sugar alternative to traditional iced coffee drinks. With 20 grams of protein, only 1 gram of total sugar, and 110 calories per 11-ounce can, it stacks up well against most bottled coffee drinks, which are often loaded with added sugar. But the full picture depends on what “healthy” means to you, so let’s break down what’s actually inside.
What’s in a Can of Slate Coffee
The base of Slate’s coffee drinks is brewed coffee and ultrafiltered milk. Ultrafiltration is a process that physically separates lactose (milk sugar) from the rest of the milk, leaving behind a concentrated, protein-rich liquid. This is how Slate gets its protein count so high without adding whey powder or other protein supplements. It also makes the drink lactose-free, which is a genuine benefit if dairy sugar normally bothers your stomach.
Beyond that, the ingredient list is relatively short for a shelf-stable drink. The Mocha Latte flavor, for example, includes cocoa, natural flavors, a small amount of salt, and a few stabilizers. It’s also fortified with vitamins A and D, similar to regular milk.
How Slate Handles Sweetness
One of the biggest selling points is what Slate doesn’t use: there’s no added sugar. The 1 gram of total sugar per can comes from the milk itself. Instead of sugar, Slate relies on monk fruit and stevia (specifically Reb M, a less bitter form of stevia) to add sweetness. Some of their other products also use allulose, a rare sugar that tastes like the real thing but passes through your body without raising blood sugar or insulin levels.
For most people, these sweeteners are perfectly fine. The main caveat is digestive comfort. Allulose in large quantities can cause bloating, gas, or mild nausea. A single can of Slate contains a small amount, so this is unlikely to be an issue unless you’re drinking several in a day or you’re particularly sensitive.
The Protein Advantage
Twenty grams of protein from a coffee drink is genuinely impressive. That’s roughly the same as a Greek yogurt or three eggs. And because it comes from real milk protein rather than an added isolate, it delivers a complete amino acid profile, meaning your body can use it efficiently for muscle repair and satiety.
This makes Slate especially useful as a post-workout drink or a mid-morning option that keeps you full longer than a regular iced coffee would. Protein is the most satiating macronutrient, so pairing it with caffeine in a 110-calorie package gives you energy and appetite control without much of a caloric cost. For comparison, a typical bottled mocha from the grocery store can easily hit 200 to 300 calories with 30 or more grams of sugar and minimal protein.
Stabilizers and Thickeners
Slate uses cellulose gel, cellulose gum, pectin, and dipotassium phosphate to keep the drink smooth and shelf-stable. These are common food additives found in everything from ice cream to salad dressing. Cellulose is plant-derived fiber, pectin comes from fruit, and dipotassium phosphate is a mineral salt used to prevent separation.
None of these are considered harmful at the levels used in food products. Notably, Slate does not use carrageenan, a seaweed-derived thickener that has drawn criticism over potential gut irritation. If you’ve been avoiding carrageenan in your dairy alternatives, Slate sidesteps that concern entirely.
How It Fits Different Diets
Slate’s macronutrient profile makes it compatible with several popular eating patterns. For keto, the net carb count lands between 1 and 4 grams per can, depending on the flavor, because allulose and insoluble fiber aren’t absorbed by the body and don’t count toward usable carbohydrates. The drinks are also gluten-free, egg-free, and kosher.
Slate won’t work for strict paleo eaters, since dairy is off the table in that framework, and it’s obviously not suitable for anyone avoiding animal products entirely. But for people who tolerate dairy and want a convenient, high-protein option, it checks most boxes.
Where Slate Falls Short
No packaged drink is a perfect substitute for whole foods. Slate’s protein comes from real milk, which is a point in its favor, but you’re still drinking a processed, shelf-stable product with added flavors and stabilizers. If your baseline comparison is black coffee and a separate whole-food protein source, Slate is a convenience trade-off rather than a health upgrade.
The caffeine content is also worth watching. Slate adds natural caffeine on top of what’s already in the brewed coffee, so if you’re sensitive to stimulants or stacking it with other caffeinated drinks throughout the day, keep track of your total intake. The exact caffeine amount varies by flavor but is marketed as being higher than a standard cup of coffee.
Price is another practical consideration. At roughly $3 to $4 per can, Slate costs significantly more than making iced coffee at home. Whether that premium is worth it depends on how much you value the protein content and the grab-and-go convenience.