Malting Corn

>> Friday, June 28, 2019

Last year I brewed my interpretation of a Wari Chicha, incorporating home malted purple corn. I've been tossing some ideas around in my head in regards to using the corn malt in another beer, so I figured I'd document my process. Here it is:

  1. Step 1, acquire some purple corn for malting. Really, any corn should work as long as it's not too old or been treated in some way to keep it from germinating. Here's the brand I bought at my local international market.
    Inca's Food, Maid Morado
  2. If your corn came on the cob like mine did, the next step is to remove the kernels from the cob. 
  3. Next, transfer your kernels to a colander and wash the corn with cool tap water. My pre-soaking weight of my dried corn was 966g.
  4. Transfer the kernels to a suitable container, such as a bucket. Top off with cool tap water, about 1" over the kernels. Soak for about five hours.
  5. Transfer corn to colander to drain. Leave it in the colander for about two hours.
    Kernels are more translucent after a soak
  6. Transfer back to a suitable container and top up with fresh water. Leave to soak overnight.
  7. Transfer back to colander and rinse well with cool tap water.  Transfer back to suitable container and top up with fresh water.
  8. 24-28 hours after starting first soak, transfer corn to your colander and rinse well. At this point, the soaked kernels weighed in at 1154g, so an increase of 188g.
    Looks like purple pomegranate
  9. Line a large shallow dish/pan with damp paper towels or dampened dish towel. Transfer corn to the dish and spread it out into a thin layer. Cover with another dampened towel and set it in a warm place.
  10. Check your corn at least a couple times per day. Both times I've done this, they've grown extremely fast. Once the shoots are about 2x the length of the kernel, it's time to dry them.
    Sprouted corn
  11. I use a food dehydrator to dry the malted corn and stop the germination process. Set food dehydrator to between 100 and 125F. Once the kernels have lost 14.2g per .45kg, it's time to increase the temps. In my case, this meant when the weight was down from 1154g to ~1118g.
  12. Increase food dehydrator temp to between 140 and 160F. It's done when the kernels have lost 85g per .45kg of its original weight. In my case, this meant down from 1154 to ~936g.
  13. Next, preheat oven to 176F. 
  14. Kiln corn malt for about four hours at 176F.
  15. Lastly, transfer corn malt to a pillow case and put it in the clothes tumble dryer for about 10 minutes to knock the shoots off.
At this point, the malt is ready to use. I store it same as I would any other grain. When it's time to mill, it seems to mill more easily if you partially crack/crush the grain first. That's about all there is to it. Cheers!