another use for spent grains

Sunday before last I brewed a batch of Red American Wheat Ale. When the wort was in the kettle heating toward boiling, I figured I'd take a moment to deal with the spent grains. Normally I just dump them in my compost pile, but my compost pile is at the top of the hill in my backyard, through a forest of weeds, and I didn't feel like bushwhacking my way up there. I looked at the plant beds alongside my patio, saw the weeds encroaching on the bare soil there, and figured I'd try the spent grains as a mulch.

Now, dealing with spent grains is a challenge faced by every homebrewer, and I've heard a lot of ideas relating to it. Some people make them into dog treats, or try to use them in baking, but neither of those methods really solve the problem--a five gallon batch of beer leaves the brewer with around eight to fourteen pounds of grains, and I've never seen a recipe for bread or dog treats that made use of more than a pound or two. Some people just pitch their grains in the compost, and that's a pretty good solution, but you can end up with a lot of compost pretty quickly--every pound of carbon-rich grains needs to be balanced with an equal amount of nitrogen-rich greens for the compost pile to do its thing properly, so you end up with two pounds of compost material (before it breaks down) for every pound of grains you're getting rid of. In the end, a lot of people just bag their spent grains up and throw them in the trash, and that's not a very satisfying solution, either.

So why haven't I ever heard of anybody using spent grains as mulch? It seems like another decent option for grain disposal, but the fact that I hadn't heard of it being practiced made me somewhat hesitant to try it on my own.

There were two main potential problems that came to my mind. One: would the residual sugar in the grains draw pestilent levels of ants or rats or other animals? And two: would the grains decompose into a stinking layer of rotten matter?

In the end, because I've used cocoa husks for mulch in the past, and because that material has certain commonalities with spent grains--and because my backyard is hardly Sunset Magazine material anyway, so it's not like I'm gonna be screwing up a work of art if this goes wrong--I decided to go ahead and give it a try. I spread the grains about two inches thick on a 3' by 2' section of bare earth.

That was more than a week ago now, and the grains-as-mulch experiment doesn't seem to have resulted in any of problems I'd been worried about (or in any problems I didn't even think of). The spent grains do seem to behave in a similar manner to cocoa husks when used as mulch--they form into a somewhat solid mat. I'm also guessing that like cocoa husks, the spent grains will break down after a season or two (as opposed to cedar chip mulch, for example, which lasts for a lot longer than that), and if it gets really damp around here, I wouldn't be surprised if they develop a little bit of mildew.

But in the end, I feel like this is a pretty good way to deal with spent grains. In fact, there's plenty other areas of my yard that could use a layer of mulch, so now I've got one more reason to brew!