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lonmower

Coffee Grounds Overload?

lonmower
12 years ago

I am returning to this forum after several years hiatus...but in the meantime I have been happily composting away.

This is my question...

I have two sources for coffee grounds (and an occasional bag from Starbucks), I am adding approximately 15 gallons of grounds per week. In addition, approximately 1 gallon of kitchen scraps and whatever garden waste becomes seasonally available. I have a source for shredded paper which I add at about 10 (non compacted) gal/week. I try to keep my piles well turned and they stay pretty hot until I stop adding materials. I also have many many red wigglers living in the piles. I have never done a soil test on the finished compost.

Can you have compost that is too much based on coffee grounds?

The coffee grounds have used paper filters in them...am I putting in too little or too much paper, and without a soil test is there some way to know that I have the right balance?

Comments (44)

  • Laurel Zito
    12 years ago

    Buy some bagged browns sheared wood and mix with. I like a lot of coffee, I never have too much coffee, only too little.

    You can use 3 part of coffee per 1 part wood and get great results. If you use less browns it will still be ok or even great, after composting.

    Coffee is only a problem if you put it on plants without composting it. Some plants die from the high acid levels. If the coffee is free, you can't really go wrong with lots of free coffee.

  • joepyeweed
    12 years ago

    If you are getting finished compost, the stuff is breaking down, within the time frame that you expect, without too much smell or other problems, then its working.

    Just looking at what you typed it does seem a bit heavy on the greens - 16 gallons of greens to 10 gallons of browns. Seems heavy on the greens, but if its not getting smelly and its breaking down promptly - then its probably just fine.

    The other thing to look at is performance of the materials growing where you are using the compost.... if you have problems on the growing end, and want more specifics - then go ahead and have the soil tested.

    There are different tests for compost versus soil. You can have just the compost tested or you can test the amended soil. It depends upon what your goals are.

  • toxcrusadr
    12 years ago

    +1 on joepyeweed's post. If it heats up but does not smell bad and makes nice looking compost, it's fine.

    I thought coffee grounds were a fairly weak green, which may be why you're not having to add a ton of paper.

    Regarding acidity, someone on a compost forum did a test a couple years back and found that the vast majority of the acid in coffee ends up in the coffee cup, so there is little left in the grounds. But there is some. I could imagine that if you put a LOT of grounds around a plant that is sensitive or in already acidic soil, there could certainly be problems until the organic acids decomposed or leached away.

  • lonmower
    Original Author
    12 years ago

    Thanks for your responses
    I thought that if it wasn't killing the worms it couldn't be too bad and the finished product does wonders as a potting mix and top dressing in the garden and I have used it as a basis for a couple of raised beds with good results.

    There is a slight odor while it is working, but I would not describe it at bad.

    I make a run to the coffe shops twice a week, and today is my day...I gotta go!

  • Laurel Zito
    12 years ago

    Coffee is a super strong green, like shredded wood is a super brown, and if you use them both together you can get hot heat fast. A coffee heavy bin breaks down very quickly. The foods in the bin just seem to dissolve away. I think the coffee still has plenty of acid in it. If one was to grind the coffee and flush it out with tons of water, the acid could be decreased, but so would the benefit of using the coffee. Acid is good for composting. By the time it breaks down it won't be harmful levels of acid to your plants. You can make very fast compost by just adding the coffee to the wood and applying it right away without even composting it. The wood sucks up the nitrogen and neutralizes the coffee. But, it would better to put it in a bin for a week or two then to just use it. Later on the wood will release the nitrogen it sucked up from the coffee back into your soil as the wood breaks down. The coffee can help the wood so it does not suck up too much nitrogen from the soil in the short term. It's great stuff, I can't praise coffee grounds highly enough.

  • joepyeweed
    12 years ago

    Once the stuff is decomposed and composted, the acid properties of the original material is gone and it should be neutral... broken down into its base components of N and C... if a compost isn't neutral then its probably not completely "finished".

  • lonmower
    Original Author
    12 years ago

    I have noticed that the kitchen wastes, including egg shells and citrus rinds, break down super fast. I do not have a thermometer but the decomposing pile stays hot as long as I am turning and adding material.
    I think what I am hearing is that as long as the pile is working never too much coffee and as a corollary...never too much paper (browns) as long as they are breaking down.
    And...that whatever acid is in the coffee is broken down if the pile is finished.

  • joepyeweed
    12 years ago

    If your pile is too brown, it will be really slow and won't be breaking down.

    If your pile is too green it will smell bad - that anaerobic smell - and you get a slimy globs of stink - that also don't seem to be breaking down.

    Basically, the more greens, the hotter and faster the process. You could try a breakpoint, keep adding the greens to push the limit to see how much you can add before it goes bad. Then its easy to correct, by just adding back in more browns.

    Once you get a base compost process down, its always interesting to change some of the variable and monitor the difference.

  • Lloyd
    12 years ago

    UCGs are considered by most to be a weak to moderate green being "slightly acidic".

    Lloyd

    Here is a link that might be useful: The Starbucks coffee compost test

  • toxcrusadr
    12 years ago

    Beat me to it Lloyd! I was about to post that same link.

    Short version: Starbucks coffee grounds were 2.28%N, but almost none of it soluble/available. Based on the organic matter content the C:N ratio was 24:1.

    30:1 being a generally accepted balance for a compost pile, I would call this a weak to moderate green. Compared to, say, grass clippings in the 5 to 10:1 range.

    Interesting, they also tilled in an enormous amount directly and liked the results!

    lon, you are doing great, rock n roll!

  • jolj
    12 years ago

    I composted many bags of coffee beans,chaff & Ground coffee in 48 inch X 48 inch X 72-96 inch high super sacks.
    I had/ am having NO problem with the UCG or the compost from it.
    The more materials you have the better, but I have dump truck loads of the UCG & chaff for free, so I use it.
    I know some of you are tired of seeing this post, but I can not cut & paste the pic.
    That is steam coming off the grounds as I spread them,Yeah I'm the Fat guy.:-)

    Here is a link that might be useful: Way Overload

  • Lloyd
    12 years ago

    I can't recall grass clippings being that strong either. I mostly go with 15-20:1 for fresh clippings. Of course YMMV.

    Lloyd

  • joepyeweed
    12 years ago

    I recall a poster on this forum, a long time ago, who added coffee grounds directly to the lawn - no composting. They did test strips on the lawn with grounds and without, and took pictures. You could definitely see the line between the test strips. The grass with the grounds was noticeably greener/lusher.

  • bi11me
    12 years ago

    What makes coffee grounds and grass clippings so good is not the N content as much as the surface area. It is easy to create good contact with carboniferous materials, they stay wet, and they can be easily mixed, giving microbes access to everything they need to go right to work.

  • Laurel Zito
    12 years ago

    I think of coffee as a super green, because it heats up the pile more the grass, which is second most likely to heat the pile up. Therefore my definition of a super green is based on what heats the pile and not what the real definition of a super green would be. If coffee is not a super green, I would like to know what heats the pile up more then coffee, because steer manure does not heat it up as much as coffee.

  • Lloyd
    12 years ago

    "Super green" I could agree with, "super strong green" I have to disagree with.

    UCG's are an excellent composting ingredient, no doubt about it.

    Lloyd

  • joepyeweed
    12 years ago

    Tropical, what makes coffee grounds heat up the pile so quickly is what Bill mentioned in the post right above yours. The grounds are in a form ready to compost, finely ground up, moist, with plenty of surface area to make contact with the other stuff in the pile...ready to rock and roll...

  • Karchita
    12 years ago

    I put UCGs directly on my lawn. A lot of people on this forum used to do that and I am surprised people don't know about it anymore. I get it from Starbucks and sift it through a sieve to break up the hockey pucks and sprinkle it around several times a year. I don't use much other fertilizer on my lawn and it works great.

    I also apply it to certain plants that I grow mainly for foliage, like lettuce, cabbage and perennials like hostas, heucheras, ornamental grasses about this time of year, as they are starting to grow again. The trick is to not cover the crown of the plant and to apply it only about 1/4" deep. It gives them a shot of nitrogen and the coarse texture of the grounds seems to help to keep the slugs at bay. (Note: It does not keep them completely away, but it helps.)

    As others have noted, it is nearly neutral in acidity. This info used to be in the FAQs and should still be there.

    I also use UCGs in my compost pile. They heat it up, but it's always a slow burn and I need to add water because they are so dry. IME, lawn clippings are definitely faster acting and nothing is faster than DH's spent grains, a by-product of his home beer brewing.

  • Laurel Zito
    12 years ago

    Starbucks grounds are so wet, that I don't have to add any water. They won't be dry unless you dried them out. The bag is always dripping coffee water as you take them home. Maybe you mean just the espresso grounds?

  • joepyeweed
    12 years ago

    A lot of people on this forum used to do that and I am surprised people don't know about it anymore.

    This forum has lost a number of experienced composters and gardeners over the years. Between censorship and the ivillage take over - lots of people have left.

  • Karchita
    12 years ago

    joepyeweed, yes that is certainly true. I am not around much myself for a number of reasons. Those annoying flashing ads are one, lol.

    tropical thought, I have been getting grounds from SB for probably six or seven years, hundreds of pounds a year, from about five different shops in my area. I have *never* gotten wet grounds from them or any other coffee shop for that matter. All I have ever gotten are very dry espresso grounds. That's the kind of coffee they mainly sell. YMMV.

  • Kimmsr
    12 years ago

    According to some sources coffee grounds have a pH of 6.8, or are slightly acidic. Keep in mind that neutral is 7.0. This list of nutrients might be useful to some.
    Can tou put too much coffee grounds in your compost or soil? Probably, although I think it would take many tons, not several pounds, to reach that. When balanced with other vegetative waste getting to too much will be more difficult.
    Coffee grounds are about comparable in nutrients to manure.

    Here is a link that might be useful: Nutrients of various materials

  • lonmower
    Original Author
    12 years ago

    Who knew this subject would create such an active thread

    On "wet grounds"...I live in a rural setting and get most of my grounds from two independent coffee shops nearby. They seem to come from 50% filter coffee and 50% expresso. They are always dry. When I get a chance, I also get UCG from three different Starbucks. They are always very WET. I do not know why the difference.

    On this forum losing followers... I began composting (and gardening) six years ago and followed this forum faithfully for several years as I was a total newbie. Then it seemed I had gleaned enough knowledge to be a fairly competent composter. Composting seems to be a fairly simple ART/Science. I was getting great results and didn't really have any questions until my recent query. I did not leave because of pop up ads or change in management. I do read the vegetable gardening forum faithfully and still think that this web site is a GEM!!!

    Now that I'm back, I realize that I HAVE been missing something while away. That you all!!! and thank you Kimmsr for your stable insight on this forum!

  • Lloyd
    12 years ago

    As far as the moisture difference between sources, I have found that businesses that make a lot of coffee often dump the grounds before the water has completely finished going through, ergo, more water in the grounds.

    Just an observation.

    Lloyd

  • Laurel Zito
    12 years ago

    Lloyd, the use up the coffee so fast, they do have to make new and dump the ground. I like the drip grounds best of all. I like the filters. The espresso grounds are a pain, you have to break up by hand. If you don't they stay just like pucks at the end of the composting process.

    But, I will take either espresso or drip, I will take as much as I can get. I can't carry that much anyway. If you have acid soil, I was reading, you could end up using too much coffee, but since I have sandy soil. It would be hard for me to get too much coffee. I have to go back and get a degree in chemistry to figure this all out.

  • bi11me
    12 years ago

    Lloyd - you are exactly right about how one gets "wet" grounds. They are the sign of good brewing technique - if allowed to "drip dry" the last cup or so in the pot is both weaker and cooler, diminishing the quality of the all of the coffee in the pot. Dry grounds are indicative of a lazy, inattentive, or over-worked barista, but it's still $2/cup.

  • Karchita
    12 years ago

    I think the difference between wet and dry is probably due to the type of coffee that is being made. Drip brewed coffee results in wet grounds (and very wet if the coffee maker rushes the process); espresso, which uses steam not water, results in nearly dry grounds. I suppose they type of coffee a shop mainly sells will determine the type of grounds you will tend to get.

    The hockey pucks are very easy to deal with. Just drop the (tightly sealed) bag on a hard surface a few times, or if they aren't in a good, strong, sealed bag, run them through a sieve. Either method only takes a few seconds.

  • Laurel Zito
    12 years ago

    I was lucky to find a bag of abandoned greens without weed seeds. I composted them and the heat is not as hot as with coffee, but it seems to last longer. However, the greens really have to be mixed in with everything else, and this was no small task. My back has been hurting for days now. I wish I had an endless supply of free greens. If I had a lot of land I would grow some kind of crop just to keep a lot of free greens, so I would not need to so much coffee. Coffee is still number one to me. It is easier to work with then greens.

  • jrmckins
    12 years ago

    Is there any problem with adding ground coffee beans (not used to make coffee)? Or even instant coffee?

  • Laurel Zito
    12 years ago

    You can add them, they will break down, but the beans won't heat up the pile as much.

  • leira
    12 years ago

    jrmckins, if I were cleaning out my cupboard, and I had unused coffee (whole beans, ground, instant) that I no longer wanted, I wouldn't hesitate to toss it into the compost bin. I wouldn't pay money for these ingredients, however.

  • jolj
    12 years ago

    I have over of one thousand pounds of not used/fresh ground coffee. I composted it all by it's self, mainly because I had chaff & whole beans too. I just did not have time to work anything into the ground coffee.
    It composted with out being turned in less then 6 months & make my tomatoes,cukes,peppers grow like weeds.
    BUT it is better to turn & add to the coffee & tea waste.
    The more balanced the mix the better the compost, but you can compost coffee/tea waste without any other material.

  • lonmower
    Original Author
    12 years ago

    Jolj

    Your post got me wondering how much UCG I have composted since I began 7 years ago. I am going to estimate (conservatively) 25 lbs/week from two local coffee shops...that is approx. 1000 lbs/year or 7000 lbs total.

    WOW-OH-WOW

    I was mixing in browns and other greens...turning...adding water when necessary. It's no wonder the garden is doing good and I am not (too) overweight

    N loaded compost will promote foliage growth at the expense of fruit production

    (FYI...coffee was invented in the PNW to combat depression caused by the ceaseless spring rain and cool weather we are experiencing right now)

  • toxcrusadr
    12 years ago

    We do about a ton per year here at our office building, since 1997, so that's about 13 tons. :-]

  • Paul Collyer
    8 years ago

    Should I ever add lime to my compost piles

  • Jon Biddenback
    8 years ago

    Paul, you'd have better luck if you started a new thread.

    I'm new to all this, but my thought is if I want to add something potentially harsh to the soil (wood ash in my case, my soil is acidic), I'm better off adding it to the compost and giving it time to leach and mix and mellow out, before I get it near growing plants.

  • toxcrusadr
    8 years ago

    If your soil is acidic and you need to raise the pH, add lime to the soil. It doesn't really help the composting process and there is no reason to add it.

    Composting actually will neutralize acids and bases. It's generally assumed that things go toward neutral in a well balanced pile. So all you'd get from adding lime to the compost is a lot of soluble calcium at a neutral pH. There is already plenty of Ca in compostable organics.

  • toxcrusadr
    8 years ago

    As for ash, it is much more alkaline and can damage plants. I used to add wood ash to my compost but I smelled a lot of ammonia - which = loss of N - and had to cut down on it. I actually think it's better to sprinkle it thinly on the soil in fall or winter and let it leach out in the off season.

  • Jon Biddenback
    8 years ago

    I don't have a huge amount of ash, maybe two or three gallons. My budget is tiny so I'm going with freebies for my garden as much as possible; don't have free lime but I did have some limbs left over from leaf scavenging, and fire.

    I'm largely composting in place as well. Adding the stuff to the soil without adding it to the compost would be rather tricky. But I'm skipping the place we've got active plants growing. Will probably put a little bit there after we cut it down for winter and before loading that spot up with OM.

  • jolj
    8 years ago

    Soil test can tell you almost every thing you need to know, including how much lime to add.

    But you can not go wrong listening to toxcrusadr, Lloyd,nbrown & a few other here on this site.

  • Bill Brooks
    4 years ago

    New to this , but boy my results have proved that you should be using it on a regular basis.

  • jolj
    4 years ago

    Bill,

    What?? The ash or the coffee chaff compost.


  • purslanegarden
    4 years ago

    And what are the results you see? Before, after, etc?