Sour Mash

Sour Mash is a process that uses material from an older batch of mash to start fermentation of a new batch of mash. The following recipe is a simple no cook mash for a simple sour mash. The corn in this recipe is used for flavor while the sugar will provide most of the fuel for fermentation. This is a multi-step process and requires a dedicated schedule and requires the distiller to make a mash almost weekly. This recipe will yield about 9% ABV and will have an original starting gravity around 1.060

Sour Mash Recipe

  • 5 gallons water
  • 7 pounds cracked corn
  • 7 pounds cane sugar
  • 2 packets bread yeast

Making the Starter Mash

Add 7 pounds of cane sugar, 7 pounds of cracked corn, and 5 gallons of 75 degree water to a 6.5 gallon plastic bucket fermenter. Once the ingredients have been added to the fermenter add the yeast starter and an airlock and let it ferment.  It will take between 7-10 days for fermentation to finish. See our articles on fermentation for more information on how to tell when fermentation is finished.

Distilling the 1st Wash- 2nd Fermentation

After the 1st fermentation is finished use an auto-siphon to transfer the liquid into the still. Don’t dump the bucket into the still- leave behind the yeast and grain- only transfer the liquid.  Add 3-3/4 gallons of 75 degree water into the fermenter as this will keep the yeast alive and happy while distilling. Only add 3 ¾ gallons of water because the rest of the liquid will come from the still after the run is finished (backset). Leave the fermentation bucket off to the side and start the distilling. The first run is not a sour mash as it did not have any backset added to it. Always do a stripping run on the first sour mash wash. Run the still hot and fast with no packing material, collect everything that comes out of the still. Run the still down until  20 proof or 10% ABV. Save this stripping run as we will add it to the next wash we distill.

After the 3 ¾ gallons of water has been added to the fermentation bucket the old corn will float to the top. Remove half of the floating corn and add it to the compost or feed it to the chickens. Add another 3.5 pounds of cracked corn to the fermenter.

Once done distilling collect 1 ¼ gallons of the left over backset (wash that is left in the still after at the end of distillation). Add the hot backset and 7 pounds of sugar to a bucket (not the fermenter) and use an immersion chiller or an ice bath and cool it to 75 degrees. Once the backset and sugar mixture has been cooled, add it to the fermenter. Add another yeast starter, a new airlock, and let it ferment for another 7-10 days- or until fermentation is finished.

Distilling the 2nd wash - 3rd Fermentation

Once the 2nd fermentation is finished use an auto-siphon to transfer the liquid into your still. Don’t dump the bucket into the still- you want to leave behind the yeast in grain- only transfer the liquid. Once the wash liquid has been added to the still add the stripping run from the first run into the still. After the wash has been transferred into the still- the fermentation bucket will have the spent corn and yeast left behind.  Add 3-3/4 gallons of 75 degree water into the fermenter- this will keep the yeast happy while you distill. Distill the sour mash whiskey making sure to discard the foreshots. Make cuts like normal and collect the tails down to 10 proof or 20% ABV. Save the tails as we will add them to the next run. I personally don’t re-run my heads I have been using them as a cleaner and solvent.

After the 3 ¾ gallons of water has been added to the fermentation bucket the old corn will float to the top. Remove half of the floating corn and add it to the compost or feed it to the chickens. Add another 3.5 pounds of cracked corn to the fermenter.

Once done distilling collect 1 ¼ gallons of the left over backset (wash that is left in the still after at the end of distillation). Add the hot backset and 7 pounds of sugar to a bucket (not the fermenter) and use an immersion chiller or an ice bath and cool it to 75 degrees. Once the backset and sugar mixture has been cooled add it to the fermenter. Add another yeast starter, a new airlock, and let it ferment for another 7-10 days- or until fermentation is finished.

Distilling the 3rd wash- 4th Fermentation

Repeat the same process you can continue this process for as long as you want to keep it going-Age the sour mash with un-charred oak chips.