Drinking coffee is the fastest and sure-fire way to wake you up and boost your energy. But did you know that the effect of coffee beans varies depending on how it was processed?

In fact, some drink black brewed coffee when on a diet to sustain them to the next meal. Some prefer mild for relaxation while some opt for strong to keep them up and active the entire day. With that said, we picked five of the strongest coffee grounds for offices that will keep their employees alert all the time.

1. Bulletproof The Original Ground Coffee
(photo from amazon.com)

The Original Ground Coffee of Bulletproof is produced from hand-picked organic beans from high altitude single estates in Guatemala. The process from picking, to roasting and packing is checked to ensure that no mold toxins develop on the product. This premium medium-roasted coffee is certified by the Rainforest Alliance, meaning it meets environmental, social and economic sustainability standards.

2. Death Wish Coffee Company Ground Coffee
(photo from amazon.com)

This Death Wish Coffee Company Ground Coffee pack is a blend of Arabica and Robusta beans, roasted slowly and ground, ready for an auto-drip coffee maker. It produces a taste that is smooth, but intense with some notes of cherry and chocolate. The product is USDA Certified Organic and Fairtrade coffee.

3. Valhalla Java Ground Coffee by Death Wish Coffee Company
(photo from amazon.com)

Still from Death Wish Coffee Company, Valhalla Java Ground Coffee is an artisan roast that has a smooth taste, unlike others that have burnet chemical aftertaste. Best for French press or drip coffee makers, your drink will have notes of chocolate and nuts.

4. Biohazard Ground Coffee
(photo from amazon.com)

Biohazard Ground Coffee is made purely of dark roasted Robusta beans. It is naturally processed from single origin beans, which means they come from the same coffee growing area. For non-coffee addicts, this would translate to having a uniform taste for your coffee as the soil and environment of the coffee tree affect its taste.

5. Military Grade Ground Coffee
(photo from amazon.com)

5. Military Grade Ground Coffee has none of the bitter burnt taste of badly roasted beans and has hints of chocolate and caramel. When you buy this USDA Organic Ground Coffee, 10% of its net goes to The Gary Sinise Foundation, which does work with U.S. military veterans.