Soggy Coffee Grounds - What Does It Mean?
The title of this blog came from one of our food service customers. The call went something like this……”The ground coffee in our group handle is always wet and soggy and the resultant drink has little to no crema, can you sort it out?”
As always an apparently simple question covers a myriad of sins but so as not to turn this blog into a book I’m going to discount some potential problem areas.
The coffee beans are fresh – stale coffee will kill crema (more of that in earlier blogs)
The water temperature is correct, if it were too low the coffee would be under-extracted – result little or no crema
The pump that pushes the water through the coffee is working fine. If the pump has failed, the result would be little or no crema
Ok, so that’s got some of the big stuff out of the way, so what’s really going on in this instance?
9 times out of 10 soggy or sloppy coffee in the group handle means that not enough coffee has been placed in the group handle. The tell-tale sign is that if you push your finger into the coffee “puck” it will sink quite easily. If the correct amount of coffee had been used there would be no “give” and the spent coffee will come out of the group handle as one solid “puck”.
So why is this important? Well when the pump on the coffee machine starts pushing water through the coffee it will do so at a pressure of around 8-10 bar. That means if the coffee can move out of the way it will. This reduces the contact time between water and coffee and results in a poorly extracted cup of coffee.
You can test this out by making a cup of coffee with a properly filled group handle and one that is just ¾’s full of coffee. The difference in the cup is obvious. Visually the crema in the under-extracted cup looks thin and light in colour and the taste will confirm what you see.
In a commercial environment there are two ways to increase the “dose” of ground coffee. If you are using a “grind-on-demand” grinder you need to increase the “grind time” within the memory. This is usually very easy to do but remember not to go mad with your increase. A lot of coffee can be ground in just ½ a second.
Alternatively if your grinder has a dispensing arm you will need to raise the plate inside the ground coffee container. This is done by unscrewing the knob found inside of the ground coffee container. More ground coffee will be dispensed when you pull the dispensing arm.
So what if the group handle appears full? Well the next thing to look at will be the coarseness of the grind. Coffee that is too coarse will allow the water to flow too quickly through it and again the crema will look light and thin as there is no time for the water to capture the coffee flavour.
All grinders (except blade grinders) allow you to adjust the distance between the grinding discs. This is true of both conical and flat disc grinders. To grind the coffee finer the blades need to be closer together and all machines will have some indication as to which direction you should choose. Once again only make small adjustments and remember you’ll need to remove the incorrectly ground coffee first, so the second or third cup will start to give you some idea as to how things are going.
If your grinder adjustment doesn’t appear to have any impact it could be that you need a new set of blades. Something else to bear in mind.
Hopefully once you’ve done the above the coffee taste you know and love will return, but if it doesn’t then the problem may lie in the bigger issues mentioned at the beginning of this blog