Unmalted Millet refuses to convert. Any Suggestions?

Kill_Devil_Spirit_Co

264gal/100% millet (2.5lbs/gal) held at approx 175 with agitation for several hours then added liquid alpha, brought down to 145 and added Beta, mixed through then added gluco-amylase. The mash itself smells great and is a very smooth porridge consistency (wasn't expecting full liquefaction). Iodine test shows up totally black though so to me that indicates just about zero conversion.

My only ideas as to why this happened was either not hot enough (i used temperatures based on fuel ethanol papers specifically for millet while I've also read taking it all the way 190-5 is useful) or full liquefaction is required which on a large scale would require one hell of an agitator. Should I have any reason to think maybe the iodine test isn't as useful on a non liquid mash like I described above?

Any thoughts?

grim

Do you have obvious bursting of the grains? I've run a number of trial batches with a similar protocol and did not have a problem. Although - I did take up to boiling and treat like maize (did not bother with beta).

Is your alpha a high temp? What was the pH? Only because if your alpha was somehow denatured, the follow on steps wouldn't show you quick conversion.

I would bring back to 150, add additional alpha and taste, skip the beta addition, instead you'll likely need to re-dose the glucoamylase when you recool - add it 120-130 - it will likely denature above 140.

I wouldn't waste the batch.

grim

Interested because we are in the process of scaling up to run a full 20bbl batch of millet.

Kill_Devil_Spirit_Co

how's your mash consistency? same sort of porridgy stuff or more liquid?

Theres a solid chance it could be a pH issue but I'm highly suspicious of the lower temps before enzyme addition. Most people go close to boiling it seems (to me). My Alpha is high temp so no worries there. Millet came dehulled and we milled fine.

Kapea

Don't grains need to be modified before you can convert starches to sugars, hence the malting process?

punkin

No, not if you introduce the enzymes outside of the grains. Google 'adjunct'

Kill_Devil_Spirit_Co

The malting process initiates the creation of enzymes needed to convert. Using unmalted/unmodified grains just requires adding them in separately. You generally have to follow the same rules regarding pH and temperature unless you use a high temperature alpha amylase.

jbierling

I love millet, almost as much as rye. @grim, where are you getting all the millet from?

I did run a small batch of millet and I'd need to double check my notes but I think I went higher than 175F. I'd try at least 190, cool to 140ish and then add enzymes.

Kill_Devil_Spirit_Co

@jbierling that was my original intention, considering that's what i've SEEN done but the guy i'm working with insisted on the 175 due to the fuel papers he read. I was under the impression high heat helped with the breaking down and lower temps required more vigorous and extensive agitation.

Any info from your notes would be very helpful. I used a high temp (up to 190F) alpha and added it at around 165F I believe.

grim

White proso - from a local feed supplier. What type are you using? Millet is a group of unrelated grains - so presumably, there has got to be quite a bit of difference between them all.

Thickness was similar to maize at the same weight/liquid ratio (2lb/1g) - but I almost always use HTAA on the heatup too. Was not the thickness of a porridge.

Kill_Devil_Spirit_Co

I used a higher grain/water ratio (2.4lb/1g) so that could explain that

grim

How did it turn out?

grim

Going to mash a 1000l batch today, will let you know how it goes.

grim

Went very well.

We mashed 49% White Proso Millet, 51% Corn, 2.2lb/gal - no malt - all enzyme. Milled the millet to a pretty fine crack.

Protein rest on the millet, pH 5.2 - ~120 for 1hr with Beta Glucanase.

Added corn and HTAA - brought to 195 and held for 1.5hr. Probably more than we needed.

As temps dropped, added HTAA, BG, and GA at appropriate pH ranges. Everything was manageable despite the thicker mash, at no point did anything ever get porridgy.

Mash OG of 1.07 temp corrected - not bad. We pushed everything a bit more than usual to guarantee we'd hit our target barreling volumes.

@Kill_Devil_Spirit_Co - you mentioned protease the other day - almost wondering if it would be helpful for yeast health with these 100% unmalt batches with non-maize adjuncts.

grim

This is now our longest running fermentation, 6 full days. 2 full days longer than typical.

We used our normal nutrient protocol, which makes me wonder if 100% unmalted fermentations need some additional help - either the protein rest/protease, or higher levels of nutrient addition.

grim

Wow, what an intensely flavored whiskey, makes rye taste mild - and this was only 49% millet.

Incredibly strong anise, black licorice, florals, dry, the intensity does not let any corn sweetness through at all, very strong spice, very assertive.

yurgle

comparable hearts yield to non-millet mash bills @grim ?

grim

Need to run the numbers and correct for the higher SG, we don't usually push as high as 1.07.

Unsensibel

I love love love millet whiskey!

grim

Certainly mellowed out after a day in the tank. We collected tails separately to give them some time to air, because there was a little hint of sweetness in the late hearts/early tails we wanted to take advantage of. I think we ended up with cuts even narrower than usual, because we are filling a barrel and destroying the remainder. I'd rather end up with a full barrel and a tighter cut, than a short-fill barrel.

I'm really hoping the anise sticks around and will stand up against the oak.