...Start to finish with malted corn
Posted: Sun Apr 26, 2015 1:43 pm
“Hey Bob, what did you do this weekend?”……..”I watched my krausen rise”….”Whoa, too much information!” 
My first two posts, “First five gallon” and “My First…Malting of Corn”, are coming together into the same story, so I am starting a new thread that combines the new distillation apparatus and the malted corn story.
Mash: The grain bill is 5 lbs of malted corn, generated as in a previous post. This was ground as fine as possible using a kitchen blender. Three gallons of room temperature water (more on the water in a bit) was added to a 5 gal stock pot. A power drill-driven paint stirrer was used to vigorously stir the water as I dumped the gristed malted corn into the pot. I turned on the heat at a moderate setting and stirred frequently until the temperature reached 60 deg C (took about an hour). I maintained this temperature for two hours with occasional stirring, then turned off the heat, and let the mash cool to room temperature overnight (12ish hours). The mash never turned extremely viscous and ended with a specific gravity of 1.038. Not great, but then again, I’m happy with any positive result at this point. I am generating a list of changes to make for the next prep, with one aim being to get a higher starting specific gravity. The pH of this was between 4-6 (not very accurate, I know; no pH meter, just crappy pH paper).
I used tincture of iodine to follow starch content. When I assessed starch in the mash after I strained a little of the material to get rid of solids (of which there was a LOT), the iodine test did indeed show a reduction in starch at the end of this period. The problem was that, if I used unfiltered mash, even a little solid material in a sample gave me a positive color reaction. Since I can’t boil the mash, I’m going to lose a lot of potential glucose in that starch that remained in the solids. But, I’ve a plan for improvement!
Ferment: About 50 gms baking yeast was mixed with a cup of the mash. This generated a krausen of about 2 inches in about 30 min. I added four cups of the mash to this and let it generate another krausen (about an hour); I added another four cups of mash and after another hour added the yeast into the mash, which had been transferred (solids and all) into a glass fermentation jug with a water trap. After less than an hour, slow bubbling was noticed on the top of the ferment, like looking at the top of a big jug of a carbonated drink. At t=24 hours, it was still bubbling slowly and steadily. I guess there’s some glucose in the mash! I’ll take the next specific gravity reading when the bubbling slows/stops.
A note on the water: After researching water on HD and elsewhere, I thought about what source to use and settled on bottled water from Nestle (Nestle Pure Life drinking water, “enhanced with minerals for taste”). This caught my eye because it has added calcium and magnesium, among other things, which I understand is necessary for a good ferment. The water analysis for this product shows that these minerals are at about half the concentration I’ve seen cited for optimal fermentation, but didn’t worry about this too much since I think the ground corn would itself provide a few more minerals and other possible nutrients for the yeast.
This is going to be a low yield batch, for sure. Even if I get a few hundred ml of hearts after distillation, I’ll be a happy camper. As I said above, there are a number of changes I’ll make to get this yield up. And I’m doing this for fun, anyway.
More later,
Bobdoe
My first two posts, “First five gallon” and “My First…Malting of Corn”, are coming together into the same story, so I am starting a new thread that combines the new distillation apparatus and the malted corn story.
Mash: The grain bill is 5 lbs of malted corn, generated as in a previous post. This was ground as fine as possible using a kitchen blender. Three gallons of room temperature water (more on the water in a bit) was added to a 5 gal stock pot. A power drill-driven paint stirrer was used to vigorously stir the water as I dumped the gristed malted corn into the pot. I turned on the heat at a moderate setting and stirred frequently until the temperature reached 60 deg C (took about an hour). I maintained this temperature for two hours with occasional stirring, then turned off the heat, and let the mash cool to room temperature overnight (12ish hours). The mash never turned extremely viscous and ended with a specific gravity of 1.038. Not great, but then again, I’m happy with any positive result at this point. I am generating a list of changes to make for the next prep, with one aim being to get a higher starting specific gravity. The pH of this was between 4-6 (not very accurate, I know; no pH meter, just crappy pH paper).
I used tincture of iodine to follow starch content. When I assessed starch in the mash after I strained a little of the material to get rid of solids (of which there was a LOT), the iodine test did indeed show a reduction in starch at the end of this period. The problem was that, if I used unfiltered mash, even a little solid material in a sample gave me a positive color reaction. Since I can’t boil the mash, I’m going to lose a lot of potential glucose in that starch that remained in the solids. But, I’ve a plan for improvement!
Ferment: About 50 gms baking yeast was mixed with a cup of the mash. This generated a krausen of about 2 inches in about 30 min. I added four cups of the mash to this and let it generate another krausen (about an hour); I added another four cups of mash and after another hour added the yeast into the mash, which had been transferred (solids and all) into a glass fermentation jug with a water trap. After less than an hour, slow bubbling was noticed on the top of the ferment, like looking at the top of a big jug of a carbonated drink. At t=24 hours, it was still bubbling slowly and steadily. I guess there’s some glucose in the mash! I’ll take the next specific gravity reading when the bubbling slows/stops.
A note on the water: After researching water on HD and elsewhere, I thought about what source to use and settled on bottled water from Nestle (Nestle Pure Life drinking water, “enhanced with minerals for taste”). This caught my eye because it has added calcium and magnesium, among other things, which I understand is necessary for a good ferment. The water analysis for this product shows that these minerals are at about half the concentration I’ve seen cited for optimal fermentation, but didn’t worry about this too much since I think the ground corn would itself provide a few more minerals and other possible nutrients for the yeast.
This is going to be a low yield batch, for sure. Even if I get a few hundred ml of hearts after distillation, I’ll be a happy camper. As I said above, there are a number of changes I’ll make to get this yield up. And I’m doing this for fun, anyway.
More later,
Bobdoe