You will receive the most benefits from celery juice if you drink it on an empty stomach in the morning. When you do this, it will help you to better digest everything else you consume over the day. If you’re unable to consume your celery juice first thing in the morning before food, then the second best option is to drink it 15 to 30 minutes before or after eating something anytime during the day. If you’re having 32 ounces a day, you may wish to have it in two 16 ounce servings. You can drink the first in the morning on an empty stomach before eating and the second 16 ounces in the late afternoon or early evening at least 15 to 30 minutes before eating your next meal.