First Try at Malting Barley, advice needed re hot/fast germination

[Not For Horses]

Hoppy, Is this a tried and tested method or stuff you've read?

1.5 times the length of the kernel would be overmodified and would start to reduce the extract potential of the grain. 3/4 to 1x the length of the kernel will be fully modified and I'd be starting to dry it now.

The concrete floor is probably overkill for most home brewers. 2 of those 50 odd litre plastic tubs from Kmart/BigW/wherever will get you 12-15kgs of malt at a time.

Turning the malt twice as a day is important to dissipate heat as well as prevent the rootlets from matting as you've already seen. You can turn it more often if you want but unless you're sitting around all day watching barley grow, you probably won't do this. And it won't really matter too much.
As an interesting side note though, it was once common among some polish maltsters (and maybe others, I'm not sure) to leave the malt untouched as it was germinating and then use a machine to tear apart the whole mess prior to kilning. Not sure why they did this mind you.

The resting thing, well I'm not really sure on that one. My malt usually sits around for a couple of weeks before I brew but then several times I've used malt that was kilned the day before brew day and not noticed anything out of the ordinary.

 

[sandybits]

Thank again Not For Horses. I was having trouble finding references for the resting or mellowing idea. This weekend my first batch will be close to 2 weeks mellowing, anyway, so I might give it a try. I'm also getting a small order of pale malt delivered from the LHBS so I'll be able to compare them, side by side.

 

[hoppy2B]

Resting it for a period after kilning is for flavour development.

On the kilning side of it I have read that the temp is gradually brought up to the 115 degrees C over several days. I've also found a reference that suggested the gradual raising of temp was necessary to prevent destroying enzymes. Raising the temp too quickly causes temperature shock to the enzymes. Raising the temperature slowly over several days avoids the shock.

My own experience with malting has been that its best to keep the grain dry on the surface to avoid mould developing. The grain will swell and absorb any water sprayed on it and having it on concrete which is porous helps to prevent it becoming too moist. Turning it over also helps with this.

@ Not For Horses. Its a combination of what I've read and observed from my own maltings. I'm not 100% sure on the acrospire length but the ten days talked about in the Encyclopaedia would correlate with an acrospire 1 and 1/2 times the length of the kernel. I will need to do some more reading before my next malting to check it.
One way to effectively use undermodified malt is to add some green undried malt to the mash. Its a method I commonly use to get a good conversion. Green malt can be put through the blender with a little water. You only need 10%.

 

[Not For Horses]

115c is pretty high for a kilning temp. Munich 2 maybe but not for ale malt.
The malt I do at home gets 85c for 4-5 hours once it has been dried at ambient.
Not really a gradual increase either, probably takes about 15 minutes for the air to heat up then maybe an hour or so for the grain to heat up.
I was talking to some maltsters in the US a few weeks ago and their green malt, once germination is complete, goes from the floor to the bag in around 24 hours.

 

[sandybits]

Well my second batch is done. I left it in the fridge (15c) for about 8 days in the end. It got a little matted and there might have been a bit of white fluff on some of the roots (mould?). However I threw it in the dehydrator for 1 day at 35c then another day around 50c. It sat for another day before I got around to putting it in the oven. It got about 5 hours in the end between 65c to 85c (up then down, then back up again...), although it was mostly in the 80c's.

A major difference I can already tell between this one and my first is that if you eat a kernel it actually tastes malty. Whereas the other one doesn't really have a malty taste. I will make a guess and say the first batch is undermodified due to the inconsistent germination (too hot).

So the question now is whether to do a protein rest with the allegedly undermodified batch, brew with it and see what happens or put it back in the oven and toast it up to another colour level?

 

[Not For Horses]

Second batch sounds much better.

I'd say toast the first batch and use it for colour and flavour with your second batch as base malt.

180c for 15 minutes will get you something light and biscuity. 30 minutes will get something like amber malt. 60 minutes will be like a brown malt.
210c for 60 minutes will get you a medium dark malt (~300L) with nice coffee notes to it (assuming it is undermodified). Keep going from there up to about 2 hours for black malt.

 

[sandybits]

Cheers, Not For Horse. I will toast it up. I can brew with the second batch and will make an educated guess that the first batch would most likely under perform it.

Thanks for the times and temps. I wonder if an acid malt can be undermodified? Off to Google...

 

[Not For Horses]

If you want a natural acid malt (commercial malt is simply acidified with the addition of lactic acid) you'll need to start with wet green malt and good temperature control.

Put some freshly germinated green malt in a vac seal bag, give it a spray with a bit of water to moisten it and seal it up. If you don't have a vac sealer then use a large ziplock back and squeeze all the air out. This is important because the reaction is anaerobic.

Put the bag in a warm environment. 35c is about an ideal temp for the lactobacillus to get to work. Leave it at that temp for 2 days.

After two days it will be looking kinda brown and slimy and nasty but this is normal. Have a taste. It should be funky and sour tasting. If it's not very acidic tasting then seal it up again and leave it for another day.

Now just dry and kiln the malt as normal. You need to kiln it to neutralise the bacteria and preserve the lactic acid profile.