Kitchen Garden Forum

The local allotment has been offered a regular volume of "steeped hops/malted barley" from the local brewery - thousands of litres of the stuff. The person running the allotment wants to know how good it is or whether it is just a soil conditioner, which they don't really need.

RHS has this:

Biodegradable mulches
These break down gradually to release nutrients into the soil and help improve its structure. Layers will need replacing when the material has fully rotted down. Among the best materials are leaf mould, garden compost, spent mushroom compost, wood chippings, processed conifer bark, well rotted manure, straw (for strawberries), spent hops (poisonous if eaten by dogs) and seaweed.

A long time ago I used to brew my own but not from tins, I used to brew in exactly the same way as a brewery does so I ended up with malted barley that had been rinsed of it's sugars and hops that had been steeped. I tried to compost them in a variety of ways but I never had a result.

The hops and barley tended to get a white furry growth and just turned everything into slime. In hindsight both the hops and barley still had traces of sugers, maybe they needed something that I hadn't thought of. I even tried a sawdust mix.

Making compost shouldn't be hard work, enough hard work in gardening.

Spent hops are an excellent manure. They can be dug in as they are, but I suggest composting them for a while. It's best to mix the hops with other materials to activate them, not so much by way of giving nitrogen but to introduce some biological activity since the hops are effectively sterile. As a manure, hops are rather more acidic than others so you may need to increase your liming, which should only really be necessary if your soil is excessively acidic to start with. The smell of spent hops is repellant to some people, and the smell persists — something to bear in mind when mulching. Also, they can blow about.