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What Is Nitrogen Flushing?

Read time: 3 mins
A bag of coffee being nitrogen flushed and band sealed to preserve freshness.
Christopher C. Apr 09, 2021

If you've ever opened a bag of Fresh Roasted Coffee, brewed a cup, and said, “That coffee is fresh!” here's why. (Also, thank you! We're very proud of our coffee.)

Once green coffee exits the roaster all shades of brown and beautiful, it begins staling. Unfortunately, this is unavoidable, but Fresh Roasted Coffee minimizes the loss of flavor by quickly cooling and bagging the beans. We use Loring Smart Roasters which have crazy-powerful cooling trays that cool entire batches in just a few minutes. From here, we transfer the beans to a bagging and sealing machine that simultaneously flushes the bag with nitrogen and seals it tight.

Bags of coffee being nitro flushed and band sealed to preserve freshness.

Going from green to good-to-go takes about 20 minutes total. That's pretty darn fast.

While every part of the process is essential for getting you top-quality, fresh coffee, it's the nitrogen flushing that really takes the cake (or cup). Nitrogen is an inert, non-reactive, odorless, flavorless, colorless, food-safe gas that is heavier than oxygen. It's also natural, making up 78% of the Earth's atmosphere! Unlike oxygen, nitrogen doesn't contribute to your coffee going stale, increasing the shelf life of your beans.

After filling each bag with tasty, freshly roasted coffee, members of our production team place the bags under a machine that flushes the bag with nitrogen, forcing all the oxygen out. The tube then moves with the bag into a band sealer that sucks out the remaining oxygen, nitrogen flushes a second time, then seals the bag.

Now comes degassing. After roasting, coffee beans continue to expel the carbon dioxide they built up, which is why we utilize bags with one-way valves. These valves allow carbon dioxide to vent out but don't allow air in—that is, until you open the bag. If you don't have an Airscape (or similar) container that actively forces unwanted air out, your next best shot at keeping your beans fresh is using the handy zipper at the top pf the bag, then rolling and squeezing it until you've pushed out as much air as possible.

If you put freshly roasted coffee in a valveless bag, the degassing process will cause the bag to balloon and eventually explode—regardless of whether or not it's been nitrogen flushed. Thankfully, popping isn't a concern for us. We freshly roast your coffee to order, bag it, nitrogen flush and seal it, and ship it right to your front door. On its maiden voyage to your home or office, it has plenty of time to degas and become the best coffee it can be.

But I want to drink coffee that came right out of your roaster!

Coffee straight from a roaster sounds more glamorous than it actually is. Right out, your coffee hasn't had time to degas, which interferes with the brewing process and detracts from the optimal taste. In other words, yes, your coffee can be too fresh. Patience is a virtue. If we could electronically send you drinkable coffee, we'd still probably let it degas a couple days, just so you're still getting the best cup possible.

Photo of the blue nitrogen lines that go throughout our large coffee pod machine.

But Fresh Roasted Coffee doesn't just stop at our bags! We also nitrogen flush our coffee pods, but they are a completely different story. To start, all the coffee in coffee pods is pre-ground. Crazy, we know. Sealing whole beans inside a pod would just make a tiny maraca, which is fun, but won't taste as good.

We're able to keep the oxygen content of our pods low because our coffee pod machine is constantly nitrogen flushing, each pod getting a total of three flushes before they're sealed tight. But before any of that happens, the coffee is roasted fresh, ground, and left to off-gas for at least 48 hours. Unlike our bags, coffee pods don't have a one-way valve, so they're more likely to explode during shipping. We find giving the coffee time to chillax before its packed is better than bouncing around on a mail truck.

Each recyclable plastic pod is first lined with a compostable filter then filled with coffee, and then nitrogen flushed. The pod then passes through another flush. Two down, one to go. Right before it's sealed, it's flushed a third time! The cups then get picked up by cute little suction cups, dropped on a conveyor belt, and are boxed up by our lightning-fast production team.

We put the “Fresh” in Fresh Roasted Coffee, legally and literally. It's our promise to you that we won't just roast your order fresh, we'll do our best to keep it fresh until you're ready to brew that first cup.


  • NS

    The delivery driver, a coffe lover, that brings my coffee orders loves when I am getting an order because of the way it fills his truck with coffee aroma. So from him and me, THANK YOU!!

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