Summer is a time when any dirt and grime on window glass is much more noticeable, but keeping windows clean without leaving behind streaks can be incredibly tricky. 

Windows are often difficult to keep clean as dust and debris will blow into them, from the outside but inside grease, dirt, cobwebs and other marks will accumulate on the glass. 

Nancy Birtwhistle, a household expert best known for winning the Great British Bakeoff, has shared there is a simple and natural cleaning method to keep windows clean without leaving behind unsightly streaks. 

In her book ‘Clean & Green’, Nancy said: “Vinegar is fantastic for glass as it cleans, cuts through grease and will wipe out any watermarks.

“Newspaper used to be grease for polishing glass after the vinegar wipe, but fewer people buy a newspaper nowadays, so I have opted for a clean polishing cloth instead, - both work well.” 

White vinegar you would put on chips is a very popular cleaning item due to its ability to get rid of stains but it is highly effective at cleaning without leaving behind streaks as well. 

Vinegar contains acetic acid, which is strong enough to dissolve alkaline window residues that often cause streaks but also evaporates cleanly so there is less chance of it leaving behind a residue. 

However, the real secret to cleaning windows is to clean them on a cool but cloudy day where it is not raining but not sunny either as the conditions will be perfect to stop steaks from forming. 

Nancy explained: "My way is to choose a dull day - don’t try to clean windows when the sun is shining on them as they dry quickly before you have a chance to polish them, resulting in streaks.”

How to clean windows properly

You will need:

• Bucket of warm water
• Washing up liquid
• White Vinegar
• Empty spray bottle 
• Very soft-bristled brush
• Dry polish cloth 
  

Method: 

To begin, use a soft-bristled brush to scrap away and dust or cobwebs away from the glass. 

Nancy said: “Brushing away any dust while it is dry will make cleaning much easier. Dust and cobwebs can be very difficult to clean once wet."

Then fill a bucket with warm water with a few drops of washing up liquid, and wipe down the window starting from the top and work your way down. 

Dish soap has been designed to break down grease while also being able to rinse of cleanly with water, so there is less chance of steaks and spots forming. 

You may need to wipe down the window twice depending on how dirty it is. 

Once the window is cleaned, fill an empty spray bottle with white vinegar, then spray it directly to the glass and use a damp cloth again to wipe down the glass. 

Use a dry polish cloth or newspaper to dry the glass, and your windows should be sparkling clean again. 

Nancy said: “Outside windows will dry quickly, so polish with your dry cloth before the vinegar has a chance to dry.

“On the inside the opposite is true, and windows will not dry quickly, so a thorough polish until dry is important for streak-free glass.”