Gluten free and starchy...

So... I decided to try to brew a mini-batch of what was supposed to be an oatmeal and buckwheat stout a it over two weeks ago.
I won't bore you with the details of Murphy's law in effect when it came to the brew day it self... Suffice it to say that my first experience with gluten free brewing was that it was extremely difficult and unpredictable.

I ended up with a demi john of 4.5 litres with what looked like badly prepared and thin porridge... OG: 1078
Seeing as my expectations were below zero and things could only get better, I added yeast and l and behold, fermentation started. After a couple of days I actually had a layer of something that resembled beer (but not stout) on top of the starch porridge that filled 4/5 of my DJ. Less than two pints were not what I was aiming for so I decided that I should try adding some amylase enzyme to the already fermenting brew along with some fresh yeast, nutrient and a bit of caramel for colour... I resumed as planned and shook the DJ vigourously. Two weeks later (with more shaking every other day) was down to 1/2 the DJ of porridge with roughly 2 litres of "beer" on top.

This is probably where I should have said "Fine, I'll try to bottle what I can, it probably won't taste very well either way..."

Needless to say; I didn't.
Instead I decided that if I just gave it one more dose of yeast and amylase, it would eat even more of the "porridge" and I could end up with more than 3 litres.
I did this two days ago, but now the starchy porridge doesn't seem to drop out in the same rate (there is still some fermentation going on) and I have at the moment maybe two inches of beer on top of the starchy porridge that fills the rest of my DJ.

Can you offer me some insight as to how this might end up (I'll leave for a few days more in room temperature with my fingers crossed before a final cold break in the shack [around 10 degrees C] and bottle what I have then)
Please feel free to tell me where I went wrong and what I could have done differently if I lose my mind and decide to try this on another time...

Unless the buckwheat is malted it needs a bunch of amylase, otherwise you have loads of starch and almost no sugars. And as you found, grotesque amounts of trub.
The oatmeal was always going to give porridge, and if you ground the buckwheat too fine that won't have helped. Better filtering of the solids after the mash would have helped, but if they were ground really fine it's difficult.

The "gone with the wheat" kits aren't bad, if you want to try a GF extract brew. They're based on sorghum syrup.

If you want to stick with allgrain, get some decent millet, malt it, roast it, and go from there - works pretty well.

I had malted the buckwheat (except for a part that I had roasted to substitute roasted barley)...
In Norway we don't have any ready-to-go GF kits, so I tried the best I could (for all I know the final result may be okay in the end)...

Oh, didn't spot you're in Norway. I imagine the postage on a GWTW kit would be crazy.
See if anybody's on ebay doing millet in Norway. When I did it as an experiment, I used some cheap stuff form an Asian grocery, but next time when I do it properly I'm going for some nice looking red millet on ebayUK. But I have to have another go at malting some maize first (may not work [again] as I bought "squirrel food" maize and it's pretty ropey stuff - but cheap)
I think the big trick is not to grind it too fine, whatever you use. I have an old homebrew book that suggests just a good crush with a rolling pin rather than an actual grind.
Or let the flour settle after the yeast's had a good go at it then rack, maybe top up, and carry on.

Well, I have now opened, poured and tasted my gluten free ale (which turned not to be anything like a stout, but never mind that).

I am pleased to say that the results were surprisingly good (considering my expectations). The last half inch should definitely stay in the bottle (as you will understand from the picture), so I will disregard the sample with the starch...
Appearance: crystal clear, deep bronze, a little bit of foam and bubbles but disappears rather quickly.
Aroma: yeasty, a bit of sourness reminiscent of an oud bruin, definite alcohol (it clocked in at 7,6 % ABV), hint of hops.
Taste: medium mouthfeel, kind of sour, hint of malt/grain, finish with definite sourness and some hops, surprisingly well balanced. Nothing in the taste indicates that this is not a "normal beer".

Cool. Clearly I shall have to add buckwheat to the list of things to try!

I had the last bottle of my millet ale fairly recently and that too was towards the slightly-sour end of the spectrum, though this wasn't noticable when it was younger.

My maize experiment isn't going well, I think I'll only get enough malted to make an experimental litre or so. Must buy better maize - it was very cheap nasty stuff!
To avoid wasting much yeast on it I'll probably brew it alongside the next batch of sorghum, it can have a bit of the yeast I use for that.

So...
Grains worth trying: millet, buckwheat, sorghum, maize. All can be malted, or you can just chuck in a load of amylase.
Millet and sorghum used in Africa for millennia. Millet used in Asia ditto. Maize used in S America likewise. I shall have to Google around buckwheat.

I'm keeping a very interested eye on the GF brewing, keep up the good work :thumb: