Two half barrels. About 31 gallons.
A gallon a week would be 52 gallons a year, and a gallon a week would be 1/7th of a gallon per day. 1/7th of a gallon is exactly 33 ounces.
38 gallons per year is slightly more than 2 by 12 ounce beers per day. That's not alot.
Beer is food.