CFW ferment and distillation questions

[baders]

Hey you lot. Just starting out with my new Brewhaus 8 gallon pot still and decided to start with Odin's CFW (and my own twist, Ryvita). Recipe;

1 x 750g packet Kellogs corn flakes.
1 x standard packet Ryvita.
3.5kg dextrose.
Cook till gelled.
Add 2 x 4g packs alpha amylase at 70 deg C for conversion. Leave overnight. Conversion of starches confirmed with iodine tests.
Oxygenate and into fermenters with dextrose at approx 26 deg C ambient. Add filtered water adjusted to 4.5 pH with citric (lemon juice).
40g EC1118 (Lowans for first batch) pre-mixed into lukewarm water, pre-tested and adjusted to 4.5 pH. Added to ferment.
Left fermenters open for 12 hrs, then sealed.

This is the result;
Seeing fermentation action but only micro bubbles all way through the process. There is movement in the mash, you can see action. No bubbling from the airlock bubbler at all. OG of this last batch was 1.080. Previous batches ranged from;
First batch (Lowans) - OG 1.052 / FG (10 days total) 1.002. Potential ABV 6.45%.
Second batch (EC1118) - OG 1.070 / FG (10 days total) 1.014. Potential ABV 7.22%. Used 20% backset.
Third batch (EC1118) - OG 1.080 / 14th day of ferment (today) SG 1.028. Current potential ABV 6.7%. Used 20% backset.

These seem like fairly poor figures ?

Fast distillation of the first two batches gave around 50% ABV.

Looking for a few pointers if I am doing something wrong with the fermenting process ?

[Doubleuj]

20% backset is pretty high, have you checked the ph of each generation?
Plus what size fermenter are you using, 3.5kg of sugar could be bumped up to 4 or 5kg of your using a 25L.
But then again your OG looks good on each so you must somehow be getting conversion from breakfast cereal, I didn’t know it was possible.

[baders]

Odin recommends 25% backset so I thought I'd be conservative. Running 2 x 30l fermenters at 22l each. Ambient temp may be playing a part with this latest batch as has dropped from 26 deg C to 20. Action is still there with currents obvious and small bubbles so I'll let this batch go a few more days. I'm still wondering about the low potential ABV readings though. I was expecting upwards of 8%. Might even try regular white sugar next lot ?

From the stripping runs of approx 6 x 22 = 132l, I've collected about 10 litres, which equates to the potential ABV at 7.57%. I made my own PSR25 controller and ran the stripping runs down to 20%. The plan is to collate the lot, cut down to 35%, and do a spirit run with copper mesh installed.

Must say though that the initial results look promising as grabbed some hearts and it is sweet sweet sweet !

Any other advise appreciated !

[baders]

For the record;

Third batch (EC1118) - OG 1.080 / 14th day of ferment (today) SG 1.028. Current potential ABV 6.7%. Used 20% backset.

It's now the 17th day and SG is down to 1.020, so I guess the yeasties are still working !

[southern45]

Might be a bit cool for the yeast, hence the slow ferment?

My gens of 30L CFW washes have all fermented out in 8 days or less, but I keep them at 28 deg C.

[The Stig]

EC1118 is notoriously slow to ferment, normally only used for fruit wash’s not cereals.

[Professor Green]

I'll second that. I had a WBAB that took a month to finish.

[baders]

OK I forgot to update this thread. That last batch got down to 1.010 from OG of 1.080 after about 3 weeks. A nice even 9% so much better. I did a spirit run at 35% on the lot and came out with about 7 litres at 85%, taking cuts all the way. Certainly some interesting noses and tastes ! Mostly butterscotch with slight acetone tinges right up the top of the heads and ever so slight wet cardboard down at the very bottom of the tails. Therefore I discarded very little at all as the "good" blend range seemed very wide.

Cut down to 65% and she's now on port soaked American Oak chips. Can't wait to try it !

Some improvements I'll be making are a couple of stainless aquarium heats to keep the ferment process nicely regulated and Fermentis Safspirit M1 yeast.