Q: After I was arrested for drunk driving in Virginia and while I was waiting to take the breath test they told me not to burp or belch.  I thought they meant to not burp or belch out loud, so when I did I kept it quiet.  Why did they tell me not to burp or belch and does it matter that I did?

A: Remember that breath testing for alcohol rests on the premise that there is a known ratio between the amount of alcohol in your blood and the amount of alcohol in your breath - so the machine is attempting to measure the amount of alcohol in the breath coming from your lungs.  If you have alcohol in your stomach, the amount of alcohol in the air in your stomach is significantly higher than the amount of alcohol in your lungs.  Burping and belching can falsely elevate breath test results by contaminating your breath sample with liquids and gases from your stomach.  Simply stated, the breath machine may have measured alcohol from your stomach rather than from your lungs.