To compost, or not to compost? It's a question we home-composters have undoubtedly asked ourselves whilst standing over the bin with an avocado pit in hand or a soaked filter full of spent coffee grounds. We'll likely still need to question whether that stale birthday cake with unnaturally blue frosting goes in or out, but we decided to catch up with Stumptown Cold Brew Operations Manager Tucker Leverton to get down to the nitty-gritty of composting coffee. 

As a home gardener, cyclist, snowboarder, and proud penner of a college-years gardening blog, Tucker also oversees our Cold Brew facility production—from brewing to team management and sustainability initiatives. And as a seven-year Stumptowner, he knows his stuff, so we jumped right in.

So Tucker, what’s the deal with composting coffee grounds?

Compost is something we’ve all likely heard about, many of us have tried, and everyone with a green thumb continues to perfect. Coffee grounds are a great addition to any compost or soil and since about 40% of the world's population consumes it on a daily basis, there's no short supply. Although not a nitrogen fertilizer, coffee is high in nitrogen and other micronutrients, which when used in garden compost makes for a nice tilthy soil base ardently sought after in permaculture. 

Do you track how much coffee we save from going to landfill?

We don't necessarily track how much coffee we save for those specific purposes; however, I do report on our annual coffee use, and just at Cold Brew alone last year we likely sent around 250,000 lbs of coffee into Portland's regional compost program, as well as directly to farmers in the surrounding area. 

Considering all we have to worry about when it comes to sustainability, is coffee compost really all that impactful?

I wish there was a data-filled report to share with you that had all arrows pointing to “yes," but I don’t. What I can say on that matter is that any steps our facility can make to progress green and sustainable initiatives and keep less waste from landfills, we're going for it.

When it comes to composting grounds at home, is it easy? Like do I just add them to my compost bin with the rest of my organic waste?

Totally. The best way to maximize use is to put the spent grounds in with your home compost and mix it up as it all breaks down into a usable soil additive. The nitrogen in the coffee helps to keep the compost hot, and even though some of that nitrogen and acidity has been lost in your hot mug of morning coffee, there's still a good amount that is helping to create rich and productive compost for your garden. There is a growing list of city-run curbside composting programs that continue to pop up all over the country, which I’d also encourage people to use if they have access. 

What about paper filters? Can I toss those in the bin along with the grounds?

Yep. There are all kinds of filters out on the market, but for the most part, one paper filter is going to break down the same as the next. That being said, there are bleached and unbleached coffee filters, which most people will notice by the different coloration of the paper itself. Both of these are fully compostable, but if you’re creating 100% organic compost, you’ll want to make sure your filters are supporting that initiative, in which case an unbleached all organic and chemical-free filter is the way to go. 

Are there other things I can do with spent coffee grounds other than composting?

There are numerous things you can use spent grounds for and our facility has provided thousands of pounds of coffee over the years for a whole list of small start-ups and creative projects. A couple of favorites have been firestarters, candles, and body scrubs. In addition, I’ve personally tried some home dying projects, but I think they’re often just seen as an unfortunate coffee-stained tee shirt.

Aside from composting, do we have any other plans for how to reuse or reduce coffee ground waste?

Stumptown is perpetually seeking innovative ways to dispose of all byproducts of production. Specifically, at Cold Brew, the composting program has been so efficient and successful that nothing else has come into play yet—but there is always tomorrow! 

Anything else we should know about composting coffee grounds?

Coffee naturally has great moisture retention and the ability to block harsh temperature swings we see during the summer. Covering exposed or shallow root systems with a nice layer of saturated coffee grounds during heat waves is a great way to guard against burnt roots and help keep the ground moist throughout the day when the sun is at its highest.

With folks like Tucker on board at Stumptown, the future of sustainability is looking good. To learn more about Stumptown's commitment to people and planet, visit stumptowncoffee.com/impact.