Optimising coffee taste

There is such a fine line between the "perfect" cup of coffee and disaster that you could make a coffee roaster very paranoid.

When anything goes wrong with the taste of the coffee the first thing blamed is the coffee. "The guy roasting the coffee fell asleep on the job", or "he mixed up the coffees" or heaven forbid "he used an inferior coffee"

Yet most of the time in the food service industry it is usually wear and tear on the equipment, a setting change, or an attempt to push the envelope when it comes to serving an extra large coffee. In the last two or three weeks I've had the "pleasure" of enlightening individuals of the various issues mentioned above.

Case 1. - A worn out set of grinding discs -

This problem is evidenced by the fact that no matter how fine you grind the coffee you can't seem to slow the flow of the water down sufficiently to achieve a "crema" or anything that resembles a decent cup of coffee.

What is happening here is, rather than the coffee being "cut" by the grinder discs it is instead being crushed. Not only that a huge amount of energy is going into the crushing process which in turn heats up the coffee sufficiently to deliver a burnt taste. All in all pretty disastrous.

Change the blades and all your problems are solved. One suggestion I had for an equipment supplier was that when the annual insurance inspection is carried out on the coffee machine automatically change the grinder blades, £35 - £40 well spent.

Case 2. - Incorrectly set blades

This can happen as blades wear. Although in theory the grinder settings should be checked on a daily basis to adapt to various atmospheric conditions this rarely happens in the food service industry. However there should be some monitoring done of the time it takes to make a shot of espresso (between 20 and 30 seconds)

When you reach 10 seconds, as sure as eggs are eggs your customer is going to complain about the insipid watery taste of your coffee. The problem is the water has no time to pick up the flavour that delicately roasted coffee can provide. Solution review your grinder settings, if you're not sure, talk to your supplier, after all it's their coffee you're destroying!

Case 3. - Pushing the envelope

I was helping to set up a machine today, a "bean to cup" variety. Now the maximum amount of coffee this machine could grind was 9 grams, however the customer had a particularly large cup. So we tried to push more water through the coffee, add more milk, basically all the tricks known to man in an attempt to fill that cup with a satisfactory drink, but to no avail.

We started out with a beautifully balanced cup of coffee, and ended up with one of the harshest cups of coffee I have ever had the pleasure of drinking.

Simply put we were trying to get flavours out of the coffee that the average human being is never meant to taste, bitter, burnt, simply nasty as we attempted to fill this cup.

The moral of the story, watch how the colour of the water changes as it runs through the coffee. When you get to the point where the thick crema disappears and almost clear water starts to run through stop the machine, and then come back from there. Don't use the cup as the guide, use your eyes. If you can't increase the dose of ground coffee, reduce the cup size. You'll do everybody a great favour and hopefully enhance coffee sales.

There all you coffee roasters can rest easy, well until the next batch of coffee that seems to have a higher moisture content than usual!