That may be the single most common problem we hear about. Either the coffee just stops or starts trickling out of the faucet. Fortunately, it usually just involves a fairly easy fix of some kind or another. Rather than go though a list of problems than talk about the fixes—I’ll just go through what we do when we encounter the problem.
- Make sure there is Nitrogen to the keg. Just pull the pressure relief valve a bit on the lid of a ball lock keg or disconnect and pull the handle down on a sanke coupler. Also look at the gauges on the Nitrogen tank. The top gauge should be above 30 psi and the left gauge above 100 psi. The shut off on the regulator should be down facing the line. All this tells you if Nitrogen is going into the keg.
- Clean the disk diffuser holes inside the stout faucet nozzle. DISCONNECT THE KEG FIRST. You can just unscrew the nozzle, tap it on a hard surface, and the disk diffuser should fall out of the nozzle. That’s the thin ‘not quite dime sized” screen with 5 or so tiny holes. Coffee grounds tend to clog those holes blocking off the flow. Just rinse it and put it back. Be careful, it is small and can get lost easily. Make sure you put back the white regulator core and any o-ring that may fall out.
- Make sure the keg isn’t too cold. We’ve seen frozen coffee inside the keg dip tube even when the coffee itself isn’t frozen.
- Finally, sometimes the grounds clog the keg dip tube. The easiest way to clear them is to release some pressure from the keg. Turn off the Nitrogen, and put the black “out” keg coupler on the Nitrogen hose where the grey “in” coupler was. Then turn on the Nitrogen (FIRST) and hook it up to the “out” fitting on the keg. That should push Nitrogen into your keg through the dip tube and remove the grounds. Then reverse what you did and put the grey connector on the Nitrogen line and the black connector on the coffee line. Never do step 4 with an empty or “off” Nitrogen, you’ll get coffee backing up into your nitrogen line. Step 4 only works with a ball lock keg—you’d have to take the sanke coupler apart to do it with a sanke keg.
If you do have grounds in your keg, you may be repeating the repair. Or you could pour from one keg to another with a funnel and filter. That’s not the best option for fresh coffee—you don’t really want to expose it to air more than necessary. Of course, the best solution is to be careful when you filter it, but you already know that.