Malting corn is easy!

[tommysb]

Haha I like to use a bit of a clickbait title. But, I would say that it's accurate. I've looked through a few old threads on here lately to get inspiration, but I have a mission to malt some corn.

EU definitions of whiskey require that it is made from malted grain, with or without the additions of unmalted grains. Therefore, no malt, no whiskey.

What do you do if you want to make 100% corn whiskey then? You need to obtain some corn malt. What if you want to make 100% corn whisky with local specialty corn? Well, nobody malts that, so you have to do it yourself!

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I took delivery of 250kg of 'Belgrano' corn grown by a local farmer, and I want to convert some of that to malt. I make batches of 500litres of wash at a time, using 100kg grain, and so want to be able to malt 50-100kg at a time.

I want to test my malting on some cheap corn first, so I went and bought a 25kg sack of feed corn for 10euro. Honestly, that stuff is not bad either, but I can see that the Belgrano is better.

Reading other threads there seems to be a couple of things you have to do to malt successfully-

1. Soak your corn, and keep it oxygenated throughout the soak and not get infected. (16-30 hours)

2. Let your corn germinate, and keep it moist, and not overheated whilst it germinates. (3-6 days?).

For soaking, one approach is to soak, drain, soak, drain in cycles of 6 or 8 hours (this allows oxygen in).
There's another thread, where someone soaks for 24 hours without draining, but use the addition of Hydrogen Peroxide (H2O2) during that soak which both helps prevent infection though its disinfecting properties, and also releases oxygen. THat H2O2 breaks down into 2H2O2 -> 2H2O + O2.


Anyway, I did a bit of both.

First, dumped the sack into a blue barrel with a tap (and filter!) and covered in water, skimming off as much floater as I could. Left a few minutes, and drained. Just to give the corn a first wash.

Then, filled, covered with water, and left it a few hours. I didn't have any H2O2 at this point, so I just left it. How long? 6 hours? 8 Hours? Something like that. The exact number doesn't matter. Then I drained it and let it air out, and went out to do some errands. Whilst I was out,, picked up 3 0.5 litre bottles of 3% H2O2.

When I got home, it have been airing for some hours. 4? 6? 8? Don't recall, doesn't matter. I refilled with water, chucked in 1l of H2O2, (probably in about 30-50 litres water - 25kg corn covered with 5cm at the top). and went to bed.

Next morning, drain, and leave a few hours. Refill. Add 0.5L H2O2 and went out for a hike. When I got home, I drained again and started to construct my malting tumbler.

This was a 500L 'dorna' used for winemaking, mounted on wheels as rollers. I threw the corn into that on Sunday night and turned a bit.

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Corn sits in the bottom of it. There's a few batons screwed to the inside to agitate corn as you turn it. (by hand for now).

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One tip - 25kg of dry corn, after hydration, weighs a lot more than 25kg!

Over the next few days I have been turning that thing every few hours, and pouring a glass of water onto the corn if i 'felt' it was getting to dry. This morning, we could clearly see some of the roots starting to grow on the corn - germination is happening!

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The root grows out of the pointed end (I think), and the shoot grows the other way. So, I put it in on sunday night, and thursday morning it was like this. It's probably about 11-15c here on average at the moment, so not too hot, not too cold.

This evening, I decided to do an experiment. I took a try of the corn, (now at 96 hours), and decided to try and turn it to crystal malt.

From 20 grains of corn picked at random, here's what they looked like. Germination present in most of them at this point.

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Crystal malt is made where you let the corn enzymes convert the starch inside the corn (to make sugars), and then raise the temp to caramelise some of those sugars. Do we have enough enzymes for that at this point? No idea. Let's try.

Anyway, loaded them into a baking tray, covered in foil, (foil to keep moisture in as we try and convert those starches) and put into the oven at 60c for one hour

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After an hour in the oven, time to check -

They grain bed didn't seem like it was at 60c. Of course, the oven just sets the air temp. THe grains were warmish and moist, but I think they needed more time. I put the timer for another 30 minutes, and switched on fan assist. Before, I didn't want to, to try and minimise drying out, but I think the heat transfer will be better so it's a good trade off.

Here's what the inside of the grains looked like after 30 mins:

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Compared to un-ovened:

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I WANT to believe there's some difference, but in honesty, if there is, it's not significant. I will check again in 30 minutes.Differences in taste at 60 minutes? I want to say 'yes', but it's subtle. The texture IS different though, with the oven sample being less hard!

Oh - the smell on this stuff! It's hard to describe, but it's much more intense and rich than unmalted corn. Honestly, I am excited about that. Anyway, going to do another update post when the corn has had more time in the oven at 60c, and then going to raise up the temp to hopfully roast any sugars into caramel.

If there's no caramelisation, I'm still going to have a few 100g of roasted corn I can still use in a mash.

I will repeat this experiment again tomorrow, and maybe the next day to see the 'best' time to start this process. I am SURE that this is too early, but hey, I don't know what I am doing so I might be wrong!