I've tried creating barrels but it just won't work.
I'm running some Spigot 1.8 version, not sure which, and Brewery 1.3.1 and nothing else.

It doesn't like like there's a "Brewery" or "PluginMetrics" folder in your "plugins" folder. Maybe Spigot isn't setup/setting it up correctly? Do you see "[Brewery] Brewery Enabled!" in your server console?

Yes, I have both of those...
And it does say it's enabled.

It should work fine... Try a small barrel!

Honestly, I have tried! It doesn't.

I'll upload my server set-up soon.

Here's a zip of my server set-up.
I had set myself as op to test your plugin.
https://drive.google.com/file/d/0B3mkhN_bOhvsRnNvT3M3QlFiN0k/view?usp=sharing

@Sn0wStorm Worked it out yet?

I'm having the same problem

My barrel does not work with the latest grief prevention. It tells me to turn it off in console.