Building a Compost Barrel

While not directly related to either brewing or cooking, I figured I would do a post on this, as it does have a couple of integration points with brewing.  Back in the May/June issue of Zymurgy, there was an article called “New Life for Spent Grains”.  I find this to be one of the articles of Zymurgy that I reference most.  The idea of the article is that there are a lot of uses for those tasty grains that get dumped out of mash tuns and grain bags after a brew day.  The article gives a few great uses for the grains after a brew day – compost for your garden, a dog treat recipe, a pizza crust recipe, and a cinnamon bun recipe.  Today’s post will put a spotlight on the compost idea, but I have made the dog treat recipe and the pizza crust recipe several times and they both work great (I will do another post or two on those down the line).

Building a compost barrel is a great way to use up materials that you would probably be getting rid of anyway, and turning them into natural fertilizer for your garden.  In my case, I plan on using spent grains (among other things) in the compost and using the compost on my vegetable garden and my hops.  Which turns a by-product of a brew day into something useful that you can use for growing hops, or whatever else you’re growing in your backyards.

The build design that the article describes is pretty simple.  Basically all you have to do is take a trash can, drill some holes in the lid and the bottom of the can to allow venting (the article recommends 1/2″ holes 6″ apart), and bam – you have a compost barrel.  They recommend layering it with one layer carbon-rich material (i.e. shredded cardboard, newspaper, etc.), one layer nitrogen-rich material (i.e. spent grains, grass clippings, vegetable and fruit scraps, etc.), and one more layer of carbon-rich material.  You then basically keep the top moist (but not soaking) and stir it up periodically to keep it warm so that it continues decomposing.  You can continue to add layers as the size of your container allows.  You know it is ready to use when you don’t recognize what the ingredients used to be (i.e. the cardboard shreds, don’t look like cardboard anymore).  Just spread it on your garden, hops, flowers, etc. to give them a rich dose of nutrients.

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My build followed the article fairly closely, but here are a few notes on what I did:

• I was able to get my hands on a used 55-gallon drum for free (thanks Harry!), so I used that by cutting the top off to use as a lid.  This saved me a little money since I didn’t have to buy a plastic trashcan, and it gave me a nice big capacity.  Since the top had to be sawed off to create the lid, I also added on an inexpensive hinge to attach the lid and make it easy to open.  That being said, picking up a plastic outdoor trashcan at the hardware store, will do the trick just fine.
• The article suggests drilling 1/2″ holes, 6″ apart in the top and bottom of the container for proper ventilation and drainage.  I did not have a drill bit that big so I used my biggest bit and drilled more holes than suggested.  I also drilled some holes in the sides of the barrel, mainly for drainage.  The point is, make sure you’re allowing enough ventilation.  When organic material decomposes, it generates a fair amount of heat and lets off some gases that you definitely do not want building up in a sealed container – so drill those holes, folks.  You need the lid to hold in some heat to keep the decomposition process going, but you want to let those gases out and you also want some drainage.  You want the mixture to stay moist, but not soaking wet.
• I did this build over this past weekend and started mine with shredded cardboard and grass clippings, because that’s what was easy for me (I just moved into a house so I have a ton of cardboard lying around that I need to get rid of and my lawn mower has a bagger on it so it was easy to dump a bag of grass clippings in).  I also have been tossing garden trimmings and fruit and veggie scraps in, and plan to dump in some spent grains after my next brew day.  Make sure to keep the top moist and to stir up the barrel once in a while to make sure it stays warm.  If the compost barrel starts to get too stinky, it means you need to add more carbon-rich material.

I just did the build and started up the barrel this past weekend so it will be awhile before I will be able to use the contents, but I am definitely excited to have some natural fertilizer for the hops and the veggies.  I’m hoping to have some compost ready to at least spread on the hops later in the season when the bulk of the hop cones will be forming (although it looks like I will be getting a small, early harvest from one of my Cascade crowns and another late season harvest like the same plant did last year, so I won’t be able to use the compost to boost the early harvest).  However, even if it isn’t ready by then, I plan on spreading the compost over the veggie garden and the hops either at the end of the season or at the beginning of the growing season next Spring to mix in the compost to give all my plants a nice boost.  If it works out well, I may even add in a second barrel.  This really is an experiment for me so I am excited to see how long it will take before I get results, and I will be sure to keep you all updated as the compost progresses.

Until next time, cheers!

Song of the Day: “The General” by Dispatch (the live version off of their live album “Ain’t No Trip to Cleveland”)

Beer of the Day: Southern Tier’s Plum Noir