Though some manufacturers claim that their acai products have a shelf life of up to a year, or one week if the product has been opened, the safest bet is to consume it as soon as possible.

Choose a retailer or manufacturer who specializes in acai supplements, as they are more likely to move the product quickly and have a consistently fresh supply. 

The most important part of the process occurs within 24 hours of the harvest, long before the product ever reaches your table.  Ensure that your supplier is processing the berries within this timeframe.