Flaked maize causing a stuck mash

[Muente]

Hello!
So I'm totally new to everything, but I have a chemistry background. I have a two brews going. One is 50% flaked maize and 50% 6-row and one is 85% flaked maize and 15% distiller's malt. I chose these as starting points for learning. I'm using a Brewer's Edge Mash & Boil with Pump. Now...the first blend had no rice hulls and I had a stuck mash that was crazy. Added a half pound of rice hulls to my second mash, but still having issues. Do I have to much flaked corn here? Any advice?

 

[doug293cz]

Yes. Flaked maize becomes mush when mashed.

You might try adding some "Glucabuster" enzyme to the mash. It is supposed to break down all of the non-starch components of the grain bill, which should liquefy most of the flaked maize (and barley as well.) Your second recipe is most likely short of enzymes for complete conversion, if you didn't add any enzymes. A good enzyme combo for your second recipe might be Glucabuster plus glucoamylase (amyloglucosidase.) First do a cereal mash to make sure all of the flaked maize is gelatinized, and then drop the mash temp to something compatible with the particular enzymes you are using.

With the above enzymes, you might have to let any solids settle out at the end of the mash and rack your wash off of the trub like you would from a fermenter.

Brew on

 

[MaxStout]

You may not be getting good conversion in that second recipe (85% maize/15% distiller's malt). Even with distiller's malt having a DP >200L, at only 15% of the mash bill, your overall DP will be hovering around 30L or so. You generally need 35-40L for good conversion.

 

[bwible]

85% flaked maize. Wow. That sounds more like a mash bill for a bourbon.

You don’t say what size batch but yeah, 85% is a whole, whole lot and 1/2 pound of rice hills isn’t nearly enough.

I’ve done pre-pro lagers with 30% flaked maize and had issues with 1/2 pound of rice hulls. And I’m doing 3 gallon batches with about 7 total pounds of grain.

 

[Beholder]

85% flaked maize. Wow. That sounds more like a mash bill for a bourbon.

You don’t say what size batch but yeah, 85% is a whole, whole lot and 1/2 pound of rice hills isn’t nearly enough.

I’ve done pre-pro lagers with 30% flaked maize and had issues with 1/2 pound of rice hulls. And I’m doing 3 gallon batches with about 7 total pounds of grain.

+1

I use a pound of hulls for 20% flaked maize and still have to manage the mash tun flow rates to avoid sticking.

With that high percentage, you’ll have corn porridge with some husks in it, so I think Doug’s on the right track to employ enzymes.

 

[MicroMickey]

Using rice or oat hulls is the right path but don't forget to lauter and sparge SLOWLY. The mash will really stick when you get in a hurry. A typical run-off for me on a 5 gallon batch is about 90 minutes. The only times I've gotten a stuck sparge were my fault for trying to go too fast.

 

[Muente]

Wow, thanks guys! Now, I've been stuck at work endlessly for the past 2 days and just checked my responses. Wish I would've seen the suggestions about enzymes earlier. Currently it's in my bucket...fermenting with Still Spirits Fast Turbo Yeast. This second batch is looking good. I'm using a Brewer's Edge Mash & Boil with the pump. So far, I'm not sure how I feel about the metal basket in there. I'm new to brewing, so I'm just figuring everything out. I asked at the store, but no enzymes were suggested.