Blood Fermentation will occur regardless of the existence of preservatives simply because blood is a biological substance which degrades over time

Alfonso Gambone
Connect with me
A Philadelphia criminal defense lawyer representing accused persons throughout Pennsylvania and New Jersey.

I’ve written extensively on DUI/DWI defenses in Pennsylvania and New Jersey through this blog and in my book, which is available on this website. In addition to these publications, I have also made videos on this criminal defense topics that affects so many people. Our law firm is constantly trying to provide individuals with information that can help people if they are faced with drunk driving charges.  


DUI Defense & Science -  You need an expert!  


DUI/DWI defenses often focus on, not only reasonable suspicion or probable cause for a car or vehicle stop and an arrest, but also the science behind blood alcohol concentration or content (BAC). While your attorney needs to have a strong command of these issues, any argument pertaining to the validity of chemical test results (blood or breath) almost always requires an expert. This individual can have a background in medicine, pharmacology, or toxicology, but your attorney can’t make arguments based on science without an expert.  


Obviously, the attorney can always make the argument but an assistant district attorney will rightfully object as the argument will be based on a field which is simply outside of your attorney’s education or training. This is the very reason why courts prohibit non-experts from testifying or even presenting arguments on these issues. 


The Blood Fermentation Defense – The Basics  


Any defense which focuses on the fermentation of blood will start with the premise that blood contains a sugar known as glucose and glucose will ferment (convert into alcohol like grapes turn into wine) due to the presence of micro-organisms. 


The most common testing device used to measure blood alcohol content (BAC) is gas chromatography. This device, however, can’t tell the tester if the alcohol existed at the time the blood was drawn or whether it was generated within the blood vial by fermentation. Since any blood sample will ferment, police and crime labs must take steps to slow the fermentation process.  


Fermentation will occur regardless of the existence of preservatives simply because blood is a biological substance which degrades over time but preservatives and other factors will slow that fermentation process or speed it up (lack thereof). 



The 3 Ways To Makes a Strong Fermentation Argument  


If youre charged with drunk driving and police have obtained your blood sample they must do the following: 


  1. The Failure To Add Sufficient Preservatives 


The blood vial needs to contain an appropriate amount of sodium fluoride and potassium oxalate anti-coagulant. In most jurisdictions, the crime lab does not put in sodium fluoride but simply orders vials from companies that are supposed to put an appropriate amount into the vial. These companies sometimes make mistakes and crime labs typically don’t test any of the vials to see if they came with the right amount of sodium fluoride.  


In this situation, however, your attorney would have to have the sample analyzed by an independent laboratory to determine if an insufficient amount of preservatives exists within your sample. Without sufficient preservatives, the alcohol may have fermented in the blood and tainted the sample. Even with the proper preservatives, your attorney can still argue fermentation because it will take place at a faster rate if the sample is not properly refrigerated. 


  1. The Failure To Mix the Preservative and then freeze or refrigerate the sample 


The person who draws the blood should be sure that the preservative properly mixes with it. This is not often done and so it presents an opportunity for your attorney to attack the validity of the sample due to possible fermentation.  


Once the sample is taken, the vial must be frozen or refrigerated. Those temperatures will slow the fermentation process, while room temperature or heat will speed it up. In many situations police won’t refrigerate the sample at all but simply put it in an evidence locker or some other non-refrigerated holding area. Trunks of police cruisers aren’t refrigerated either. 


  1.  The Failure To Promptly analyze the blood sample or specimen  


The longer the blood sits after it is drawn the more fermentation can take place. In some situations, a blood sample can remain untested for a month.  


Fermentation is incredibly useful in a DUI defense especially where a BAC is extremely high (over .16). Its’s even a stronger defense if a person performs reasonably well on a field sobriety test but nevertheless has an alleged high BAC. 


For more information on DUI defense I encourage you to keep reading my blog and subscribe to my monthly newsletter. 

Be the first to comment!
Post a Comment