A short time
one beer will rarely raise the blood alcohol
level to more than 10 mg percent (0.
1 grams percent), and we metabolize that amount in about one hour. So two hours or so after drinking the alcohol level should be zero. However, there are other tests, like ethyl glucuronide and ethyl sulfide, which test alcohol metabolites and they can remain positive for 1-2 days, depending on the test used.