Shop › Old Elk Small Batch #6 Sour Mash Reserve Image 1 of 1 Old Elk Small Batch #6 Sour Mash Reserve $119.99 Only 2 available Old Elk's signature high-malt mash bill, with a different yeast strain. This 30 barrel small batch is aged for 6 years. Quantity: Purchase Added! Old Elk's signature high-malt mash bill, with a different yeast strain. This 30 barrel small batch is aged for 6 years.