Coffee tastes of cleaner or descaler after maintenance
The drinks made after cleaning or descaling taste soapy, chemical or sharply sour.
Applies to: Espresso machine, Espresso, Filter coffee
Safety note
Discard any drink that tastes of cleaning product. Never mix cleaning and descaling products in an attempt to neutralise one with the other.
Why a cleaned machine can taste of the cleaner
CoffeeHQ explanation
Espresso detergent and descaler are both made to cling to and dissolve deposits, and both leave a residue wherever they have been until it is rinsed away. An espresso machine has more hidden volume than it appears to: the group, the valve behind it, the pipework, the boiler or thermoblock, and the tank. A rinse that looks clear at the spout can still leave product further back, and the next coffee picks it up.
The two taints are different. Detergent residue tastes soapy or chemical and often leaves the crema thin, because detergent breaks foam. Descaler is an acid and tastes sharp, sour or metallic. Knowing which you taste tells you which circuit to rinse.
Causes, most likely first
There are 3 likely causes, listed with the most probable first. Work down the list and change one thing at a time, so that when the problem goes away you know which change fixed it.
Cause 1 of 3 · Commonly the cause
Insufficient rinsing
- How to check
- Did you rinse beyond the minimum the instructions specify?
- What to change
- Run several more plain-water cycles or tanks through, including the steam wand and hot-water outlet.
Cause 2 of 3 · Commonly the cause
Too much detergent or descaler used
- What to change
- Measure to the stated dose next time; a stronger solution does not clean better.
Cause 3 of 3 · Reported, not independently verified
Residue held in the group or in a puck screen
- What to change
- Brush the group, and rinse or soak any screen separately.
If none of these fixes it
Check the cleaning and descaling guide. Equipment that needs maintenance can cause several of these symptoms at once, and no change of recipe will correct it.
Work through it for your setup
The causes above are general. These go to the part of a diagnostic that takes this symptom one check and one change at a time.
- Care, by sign and by the manual: espresso machineThe habit with every use, what to check and what triggers a job
- What builds up: coffee oilsWhat it does to the cup or the machine, and how you would notice
Rinse the circuit that was treated, with fresh water
After detergent, repeat the backflush with plain water until the discharge runs clear and has no foam, then rinse the basket and portafilter under the tap. After descaling, empty and wash the tank, refill it with fresh water and run it through both the group and the steam wand, more than once, following the quantity your manual gives. Then pull one shot and throw it away. Coffee is a good solvent and will carry off what plain water left.
When the quantity was the mistake
More product does not clean better; it only takes longer to remove. A dose larger than the maker specifies leaves proportionally more to rinse out, and a descaling solution mixed too strong can also attack seals and metal. Use the amount on the packet or in the manual. A puck screen, if you use one, is a common hiding place: detergent lodges in its mesh, so remove it and rinse it separately.
Easily confused with
- A harsh or rancid taste — Rancid oil tastes bitter and stale and was there before you cleaned. A soapy or sharply acidic taste that appeared straight after cleaning is the product.
- Sour coffee — Descaler residue is sour in a metallic, chemical way and affects every drink, including plain hot water from the machine. Taste the water on its own to tell them apart.
What not to change at the same time
Do not re-dial the grind to correct a taste that began with cleaning. Rinse until plain water from the group tastes of nothing, then judge the coffee.
How to tell it is fixed
Hot water drawn from the group and from the wand tastes and smells of nothing, and the first shot kept has normal crema.
Related issues
Work it out
Interactive tools that take you through this one change at a time.
Learn the technique
Step-by-step guides to the skills this problem comes from.