I’d suggest marinating for at least 2 hours.
This time is enough for salt penetration, which is the main purpose of marinating beef jerky (to fight off microbes).
In terms of maximum time, I’d suggest 16-24 hours.
Why 2 Hours Minimum?
Because beef jerky is cut 1/8-1/4″ thick and it takes 2 hours for the marinade to completely penetrate.
From experiments by Greg Blonder, he observed:
- In 2 hours, wet brine was capable of penetrating the meat 7 mm or 0.27 inches (roughly 1/4 inch).
Which happens to be the recommended thickness of jerky.
- In 24 hours, the wet brine was capable of penetrating the meat 17 mm or 0.667 inches (roughly 2/3 inch).
Since jerky takes a while to dehydrate (3-5 hours), people typically do it the next day.
From the above we know that the marinade should entirely saturate the meat since 2/3″ is greater than 1/4″.
Is There an “Optimal” Way to be Marinating?
Use either ziplock bags or a non-reactive container (like glass) and submerge the meat in the marinade.
If you’re using a ziplock bag, try to force out as much air as you can.
Can you Marinate for Too Long?
In terms of food safety, the USDA says 5 days.
BUT depending on the ingredients in your marinade, the protein components of the meat may break down and become less appetizing.
More or less, it could turn to mush if marinated for too long (24+ hours).
Good examples include stuff like:
- Acids like vinegars and citrus fruit juices.
- Proteolytic enzymes from fresh fruit like Pineapple, Papaya, kiwifruit, etc.
Enzymes from fruit in particular are quite strong and can quickly make your beef jerky chalky tasting.
Again though, the only ingredient that really matters here is salt.
Why Does Salt Matter So Much?
Salt kills microbes because of the effect of osmolarity – it pulls moisture out of the meat and decreases water activity.
The lack of water activity makes it unfavorable for these microbes to grow.
Soy sauce is commonly used because it contains TONS of salt and it’s a flavor enhancer.
