What is Rising Blood Alcohol?
If you’ve been arrested for driving under the influence (DUI) in California, you may feel like your situation is hopeless—especially if your chemical test showed a blood alcohol concentration (BAC) of 0.08% or higher. But DUI cases are rarely as straightforward as they seem. One of the most common and sometimes effective defenses an experienced California DUI attorney can raise is called the “rising blood alcohol” defense.
What Does “Rising Blood Alcohol” Mean?
When you consume alcohol, it doesn’t immediately enter your bloodstream and effect your central nervous system. Instead, your BAC gradually rises as your body absorbs the alcohol through your stomach and small intestine. This process can take anywhere from 30 minutes to two hours, depending on factors such as:
How much and what type of alcohol you consumed,
Whether you had food in your stomach,
Your body weight and metabolism, and
The time between your last drink and your BAC test.
Because of this, your BAC at the time of testing can actually be higher than your BAC at the time you were driving.
Why This Matters in a DUI Case
Under California Vehicle Code §23152(b), it’s illegal to drive with a BAC of 0.08% or higher at the time of driving—not necessarily at the time of your breath or blood test.
If your BAC was still rising when you were pulled over, you may have been under the legal limit while driving, even if your test results taken 30 to 60 minutes later showed a higher number. This is the basis of the rising blood alcohol defense.
Example of Rising BAC in Action
Imagine you have two drinks just before leaving a restaurant. You start driving home immediately. Ten minutes later, you’re stopped by an officer, who begins a DUI investigation. By the time you take a breath or blood test—say, 45 minutes after your last drink—your body has continued to absorb alcohol, and your BAC has increased from 0.06% while driving to 0.09% during testing.
In this situation, your lawyer could argue that your BAC was below the legal limit when you were actually behind the wheel, and therefore you were not driving “under the influence” within the meaning of California law.
How an Experienced DUI Attorney Can Use This Defense
A skilled California DUI defense attorney can use the rising BAC argument by:
Reviewing the timing of your traffic stop, arrest, and testing;
Examining chemical testing records to determine when and how your sample was collected;
Consulting with toxicology or forensic experts who can calculate your approximate BAC at the time of driving;
Highlighting inconsistencies in the officer’s report, such as the absence of clear signs of intoxication.
When presented effectively, this defense can lead to reduced charges, case dismissal, or an acquittal at trial.
Other Factors That Support a Rising BAC Defense
Several circumstances can make the rising blood alcohol argument stronger:
You had your last drink shortly before driving;
You showed little or no signs of impairment during the stop;
There was a significant delay between your arrest and the BAC test;
The breath testing equipment may have calibration or timing issues.
Get Help From an Experienced California DUI Lawyer
Every DUI case is unique, and timing can make all the difference. At the Davis W. Hewitt Law Office, we understand how to analyze DUI evidence, challenge unreliable test results, and build persuasive defenses like rising blood alcohol. Call Davis to schedule a free and confidential 30-minute consultation at his Chico Office.
