Vinegar and Bicarbonate of Soda in the Dishwasher: Does It Work?

Using household products in the dishwasher has become increasingly common in many kitchens, particularly among people hoping to cut costs or avoid harsher chemicals. Among the many popular mixtures, vinegar and bicarbonate of soda in the dishwasher often stand out because of claims that they provide a deep clean, eliminate odours and unblock the appliance. However, the results do not always live up to expectations and can sometimes cause unwanted effects.

What really happens when vinegar and bicarbonate of soda are mixed in the dishwasher?

Putting vinegar and bicarbonate of soda into the appliance at the same time triggers an immediate chemical reaction, producing foam and releasing carbon dioxide. Although this fizzing can appear to indicate powerful cleaning, its actual cleaning effect inside the dishwasher is limited.

Vinegar is a weak acid, while bicarbonate of soda is a weak base. When they come into direct contact, they neutralise each other. As a result, much of the vinegar’s grease-cutting ability and the bicarbonate’s mildly abrasive action are lost. Excess foam can also reach filters and hoses, potentially contributing to minor blockages and unusual noises over time.

Do vinegar and bicarbonate of soda actually clean the dishwasher?

Some home tests suggest that adding vinegar to the detergent dispenser and sprinkling bicarbonate of soda across the base can leave the dishwasher smelling more neutral immediately after a wash. Greasy glasses and cutlery with light marks may occasionally look cleaner, but this does not ensure deeper or safer hygiene.

When they are used separately rather than directly mixed, and in moderate amounts, vinegar and bicarbonate of soda may help with lingering odours and limescale marks. To clarify when each product is most useful in the machine, these are their most common applications:

• White vinegar can assist with removing mineral deposits and certain water marks from the interior walls and baskets.
• Bicarbonate of soda helps neutralise odours and can support the removal of light dirt from filters and removable components.
• Mixing them at the same time reduces their cleaning effect because the acid and base chemically neutralise one another.
• Too much foam inside the appliance may interfere with water circulation and motor performance.

How to clean the dishwasher safely at home

For anyone looking for a more home-based option without risking the appliance, vinegar and bicarbonate of soda should be used in separate stages. This allows each product to work more effectively without creating an intense fizzing reaction inside the dishwasher.

1. Cleaning filters and removable parts: Remove the lower basket, take apart the filter according to the manual, and wash it under running water with mild washing-up liquid. Bicarbonate of soda can be used as an additional aid by gently scrubbing with a soft sponge to loosen built-up grease.
2. Vinegar cycle: Once the manual cleaning is complete, place a cup of white vinegar upright on the upper rack and run a short or dedicated cleaning cycle with the dishwasher empty. This can help dissolve grease deposits and internal limescale marks.
3. Occasional bicarbonate of soda use: After the vinegar cycle, sprinkle a thin layer of bicarbonate of soda over the bottom of the machine and run another quick empty cycle to help neutralise odours.

Is it worth replacing detergent with vinegar and bicarbonate of soda?

Completely replacing dishwasher detergents and rinse aids with vinegar and bicarbonate of soda is not considered suitable in comparative tests. Dishwasher-specific detergents are formulated to work at high temperatures, break down grease, control foam and protect internal components-functions that household products cannot guarantee in everyday use.

With frequent washing, not using a suitable detergent can leave plates, glasses and pans with invisible grease residue and may also impair drying. Vinegar and bicarbonate of soda are therefore better used as occasional aids for internal dishwasher maintenance, rather than as full replacements for the products recommended by the manufacturer.