Ask Mr. Wizard

Curing Sparging Woes


Mark Connell — Bedford, Massachusetts asks,

I have been making a pumpkin ale for the last 7–8 years. Because I put flaked oats into the grain bill, I have always used rice hulls to prevent a stuck sparge; however, 3 out of the last 4 batches, my first runnings and sparge have been very slow. During my last batch, it took an hour to get almost 2.5 gallons (9.5 L) using 7 gallons (26.5 L) of strike water. I sparged with another 5–6 gallons (19–23 L) of water and it took almost an hour to collect as much as I could. In the past, it has taken longer than other styles to collect wort but not this long. Could I possibly be using too many rice hulls on the bottom of my mash tun? I put the rice hulls on top of my false bottom and mix into the grains. I use a 10-gallon (38-L) water cooler as my mash tun. Grain bill: Pale malt, Caramunich® malt, Munich malt, caramel 40L, flaked oats, white wheat malt, and Victory® malt for a total of about 13 pounds (5.9 kg) for A 5-gallon (19-L) batch. My last batch was double. I also put about 30 ounces (850 g) of canned pumpkin in the mash.

The likely culprit to this problem, assuming that you have been using the same basic recipe over the last 7–8 years, is beta-glucan from the flaked oats. I am betting on this
Response by Ashton Lewis.