Results from Our Coffee Grounds Survey
Spent coffee grounds are the perfect compost input:
We wondered what was happening to all those grounds. Are they going to the landfill or being reincorporated into the earth? This concerns over 7.5 million tons of organic material generated each year. If we just reclaim coffee grounds, we can make a significant difference in the volume of organics recycled rather than landfilled.
We conducted a survey which provided a wealth of information on the use of coffee grounds in the garden as well as the collection of spent grounds. The results were published in a 42-page report. Some of the results from that report are presented here.
Recycling Spent Grounds
More respondents have used coffee grounds for gardening or composting (87%) than actually drink coffee (81%). This means that people are responsibly disposing of coffee waste generated by others -- highly commendable! In some cases, grounds were generated within the same household, i.e., the respondent did not drink coffee but a spouse or other household member did. In other cases, respondents did not drink coffee but composted grounds which were obtained from a neighbor or relative. And there were quite a few who brought home grounds from the coffee room at the office. These are all great sources.
The most common uses for coffee grounds were in compost piles and/or worm bins, added directly to the soil, or as mulch. Of those participants who answered this question, 88% used grounds in compost piles or worm bins. 29% used as mulch, and 10% incorporated their grounds directly into the soil. Several participants applied grounds to houseplants. Many respondents reported other uses where grounds worked well for them or used grounds on specific plants.
Collecting Spent Grounds
A high percentage of people compost spent coffee grounds, and there seemed to be a willingness to collect them from neighbors, friends, and work places. Surprisingly, only 13% of respondents had collected grounds from shops.
Although there were reports of composters collecting grounds or other organics from work, gas station, church kitchen, fast food restaurant, cafe, juice bars, and a tea room, the idea of using coffee shops as a source of spent grounds had not occurred to most of the respondents in our survey. Many promised to start right away.
We asked those who did not collect grounds why they didn't. Here are some of the objections (O) which we received and my response (A for "Answer")
O: I do not patronize coffee shops.
A: Neither do I. I don't even drink coffee and they are glad to give their
grounds to me.
O: I haven't asked because I don't want to be rebuffed. I don't think
workers would be willing to take the time to put them in a special container.
A: Insecurity? Ask! They may already be putting them in a separate bag.
They may be delighted to do this for you. They may be eager to please a
customer. If not, they will say "no". Surely that wouldn't be too traumatic.
O: I did not know who to ask.
A: Ask any employee and they will direct you to the correct person.
Ask the manager if you want to set up an ongoing system. If you just want the
grounds they have on hand, walk up to the clerk and say, "I would like to have
your spent grounds because I use them in my garden. Do you discard them in a
O: Too embarrassing to ask for other people's garbage.
A: Call it "organic waste" instead of "garbage" -- problem solved. Spent
coffee grounds are a fruit nut that has been ground and had boiling hot water
poured through it. It isn't medical waste, or something that has been in
someone's mouth. It is the cleanest garbage around.
Those of us who understand the value of organic materials must spread the word
to those who don't. You might be surprised at how fascinated some shop clerks
can become with a person who finds spent coffee grounds useful.
O: I live in Brooklyn, NY (USA). Lots of coffee shops, but people would
I'm nuts. This could be a good thing, though.
A: If you compost, I can give you a list of people who already think you are
nuts. You have nothing to lose.
O: I tried getting greens for composting from a grocery store and they
at me like I was a "dumpster diver" who had wandered into the store.
A: Bad experience. They probably thought you were looking for a free dinner.
No one will think that when you collect spent coffee grounds. And another
benefit -- coffee grounds smell good! By the way, accent the word "spent" when
you ask for "spent coffee grounds". Two survey participants reported that, in
separate incidents, confused clerks finally handed them a package of unused
coffee grounds, not certain as to why the requester felt she should get them
The most common "excuse" was concern that a shop clerk might think the request was strange. It is surprising that people would allow the passing opinion of a complete stranger to determine their behavior. However, these comments were quite sincere.
A lack of confidence, shyness, or awkwardness usually results from uncertainty as to correct behavior in a specific social situation. Because this appears to be a problem for a significant number of people, Part III: "Guide to Coffee Grounds Collection", provides information that will allow a composter to confidently approach store personnel.Experiences in Grounds Collection
Following are a portion of the grounds collection experiences reported by survey participants when asked how often they collected grounds. Note the variety of time intervals between pick-ups, formal vs. informal arrangements, number of shops involved, and amount of grounds acquired.
A whopping 84% of our respondents said they would be more likley to patronize a coffee shop that was environmentally responsible, all other things being equal!
Subscribers to our newsletter received the full report:
Part I reports information about how the survey was conducted, geographic location of participants, personal use of coffee and coffee grounds, and how and when coffee grounds are used. In addition to the study results, Part I also includes a list of coffee resources on the Internet, as well as notes on how to use coffee grounds in the compost pile and C:N ratio information.
Part II reports statistics and comments on the use of coffee shops as a source of spent coffee grounds. It includes objections to collecting from coffee shops, collection arrangements which have been used by respondents, as well as both positive and negative experiences during collection. Respondents also provided many suggestions as to what shops could do to encourage patrons to collect grounds.
Part III is a Guide to Coffee Grounds Collection. This Guide gives actual experience in collecting grounds from start to finish, a Questionnaire for the reader to complete with instructions as to how to analyze your answers to discover the type of collection methods that are right for you. Finally, it gives a step-by-step procedure for grounds collection.
Part IV is a bonus issue included with this report. In responses to the survey, there was confusion as to whether composters should expect to pay for spent grounds, get them for free, charge a fee for removing wastes for shop owners, or consider it an even exchange. This is a question that often arises. Part IV explains how the answers to this question are determined. It is titled Composting & Economics: Supply and Demand of Compost Inputs.
Sorry, the full report is no longer available in print. It is on my to do list to get it scanned in and make it available.