Mash quit fermenting and restarted

Production methods from starch to sugars.

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rtalbigr
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Mash quit fermenting and restarted

Post by rtalbigr »

No biggy here, mostly an observation but was wondering if anyone else has experienced this.

I'm making some Tennessee Sourmash, 84% corn, 8% rye, 8% malted barley w/a little alpha to help things along. Cooked corn until it was nice and starchy, added malted barley and alpha @ 155F. Fermented on grain w/5T baker's yeast. (Total mash vol is 5.5 gal)

After 5 days no bubbles from airlock. Seperated grain and lightly sparged and put in carboy to clear. After 3 days no clearing but noticed last night bubbles on top so I put an air lock on carboy. This morning the things still bubbling at about 1/sec. Interesting. Thing is when fermenting I use brew belts to maintian steady 80-85F temps in fermenter but for some reason fermentation stopped and then restrated after grain separation. One thing I did notice when I seperated off the grain is that there was no trub at bottom of fermenter, apparently it was mixed in with the grains. W/o the grains in the carboy I can see a nice trub bed at the bottom.

Big R
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Tater
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Re: Mash quit fermenting and restarted

Post by Tater »

Try a search on secondary fermentation . I seem to remember theirs some info about it here and parent site.
I use a pot still.Sometimes with a thumper
rtalbigr
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Re: Mash quit fermenting and restarted

Post by rtalbigr »

This isn't an issue for me but I'm just curious as to why it occured. Really it just extended my ferment time a couple more days and this morning the wash is settling and clearing nicely and I should be able to rack and distill it tomorrow or Saturday.

I did several searches that weren't very productive and ended up back at the parent site re-reading the section on fermentation. After several hours (had to read it twice for some of that stuff to sink in; organic chemestry was a real pain for me) I've come to these conclusions.

1) Because I was fermenting on the grain I think the yeast eventually flocculated within the grain mash instead of settling to the bottom. The grain acted sort or like a filter and held the yeast in suspension. I think that sort of localized the yeast not allowing it to fully use all the available nutrients.

2) When I separated the grain and the wash it redistributed the yeast and remaining nutrients, re-introduced oyxgen, and the yeast began to propigate again. It proceeded slowly because the majority of the nutrients were used up and most of the sugars had been converted.

3) I'm wondering now if when fermenting on the grain it would be advisable after a few days to agitate the mash.

4) Just to experiment I had another ten gallon of the same mash about 3 days into the ferment so I seperated it of the grain, put it back in the fermenter, and it's still bubbling as I would expect it to at this stage of fermentation. I'm going to do several more runs wiht this grain bill and I think on my next mash I'll open and stir after day three and see what results.

Big R
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Dnderhead
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Re: Mash quit fermenting and restarted

Post by Dnderhead »

yeast will be the last to "settle" out.this is one way that some "harvest" yeast.
you can stir the mash,but most advise against this,as you can incorporate 02 or
bacteria and cause more harm than good.
real "secondary" fermentation is caused by bacteria and in most cases should
not be encouraged.
rtalbigr
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Re: Mash quit fermenting and restarted

Post by rtalbigr »

I wans't trying to "encourage" a secondary fermentation, merely trying to figure out why this particular fermentation stopped and restarted itself. Also, I was looking to see if there was something I could do to encourage a more complete fermentation which it appears to me I wasn't getting, although when I seperated the grain the wash tasted real dry to me. I don't think there was any introduction of bacteria because I always clean my equipment with anti-bacterial dish soap and hot water very throughly.

Never-the-less, I do appreciate your comments.

Big R
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Re: Mash quit fermenting and restarted

Post by GrayGull »

rtalgigr,

I'm interested in your 'Tennessee sour mash'. Your grains are in %, but I wondered how much grain you use for a 5.5 gallon mash. I have abandoned sugar, e.g. UJSSM, good though it is, except only for Rum.

Your recipe is exactly what I have in mind to try. I have been producing 100% malt barley whisky, of moderate quality; and I'm keen to explore some of the old and traditional product using my classic 25 litre potstill with thumper.

Also, I'm unsure about the 'sour mash aspect'. UJSSM keeps the same yeast going with sugar added in each fermentation, but I don't want to add sugar. How therefore to maintain the 'sour mash'

[Apologies if all this displays my naiviety and the answer is available elsewhere. I have actually read everything on this site for the past three years and have printed the parent site content. And distilled more than 200 litres of spirits of various kinds in my small hobby fermenter/pot still. Your, and any other generous minded contributor, is more than welcome to add to the reservoir of community knowledge. Thanks - and deepest sympathy for all the HD family and others who have been affected by the Queensland floods ...]
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rtalbigr
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Re: Mash quit fermenting and restarted

Post by rtalbigr »

GrayGull:

This is my first attempt at sour mash so I'm kinda winging this as I go, doin' some experimenting to see which way I'll go with this in the future. This recipe is supposed to be the one used for George Dickel. I too mash in 5.5 gal volume so I'm using 8.4 lbs cracked corn, 0.8 lbs rye, and 0.8 lbs malted barley, doing two at a time for an 11 gal mash. I wasn't satisified with my results after the first so I up the malted barley to 1.6 lbs to get a better conversion. I also add enough sugar to get my SG up to 1.070 which amount to about 3 lbs. As I understand the main component making it sour mash is using backset from a previous distillation. It keeps your mash acidic and provides some continuity from batch to batch. I'm using about 1.5 gal of backset for each mash. I cook my corn at a slow simmer for about 15 minutes. Others cook longer (I've seen as much as 90 min) but I have found cooking beyond 15 min doesn't gain anything for me. I add the rye and then cool to 155F add a little alpha just to thin the mash a little and then thrown in the barley. At 85F I add the sugar, 1t gypsum, 5-6t yeast nutrient, and 5-6T Baker's Yeast that's been hydrating for at least one hour. (I've got 5 different yeasts and am just trying baker's this time). Ferment takes about 7 days. After seperating off the grain settling/clearing takes about 3-4 days.

Today I'm starting another mash and doing some more experimenting. I'm using 1/2 the grain from the previous mash, 4.2 lbs new cracked corn, 0.8 lbs rye, and 1.6 lbs malted barley. I put the new cracked corn in 2 gal water last night to pre-soak. Instead of pitching new yeast I'm going to use about 1/3 of the yeast bed left from the last mash.

I do my spirit runs using 50/50 low wines/wash. To this point I've done some stripping but haven't got to a spirit run so I can't make any assessment as to my final product. I have a couple of 1L barrels for some of this and I'll put the rest in glass w/oak strips.

I hope this is of some help for you. Beside all the likker I get what I like most about this hobby is the experimenting!

Big R
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Re: Mash quit fermenting and restarted

Post by Bushman »

Dnderhead wrote:yeast will be the last to "settle" out.this is one way that some "harvest" yeast.
you can stir the mash,but most advise against this,as you can incorporate 02 or
bacteria and cause more harm than good.
real "secondary" fermentation is caused by bacteria and in most cases should
not be encouraged.
I have a question for you Dnderhead, in the Birdwatchers Recipe Tater suggest to leave the fermentation for three days in a loosely fitting container then move it to a carboy and use an airlock. He does say that this step may not be necessary. Isn't this step taking the risk you are referring too? I am about to start this recipe for the first time and am wondering if I make a 5 gallon wash in a six gallon container if I can just go to the airlock and not worry about it overflowing. I plan to control the temp at about 25C.
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Re: Mash quit fermenting and restarted

Post by Dnderhead »

Open fermenters are no problem with vigorous ferments,the co2 makes a "blanket" that keeps the"bugs"out. after the ferment settles to a slower
action closed is better.as then it does not have the "blanket" of co2.
this is done with other ferments as well like wine.this saves on head space
and over flowing fermenters. some times a secondary ferment is introduced
on purpose,as this can in some add/remove flavors.
(one is malo/lactic ferment/wine)
( this makes a "softer" wine as it works on lactic acid)
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Re: Mash quit fermenting and restarted

Post by Maltbar »

had almost the same problem & was told to just chill out!
Take a chill pill...after no bubbles in one wash, some bubbles in
2nd, , etc etc., I began to 2nd guess the Standard Operating Procedure, t
But I was told 'dont worry' & It was difficult but after chilln out for 5 days on one, and 7 days on the other, I took a peek under the hood and there it was, a lovely Kr-ring, indicating some level of fermentation. Tonight allz
well and I'm sitting here chillin w/some Highland Park 18yo confident
in knowing that nature knows the drill much better than any of us!
So cheers maltster & just remember to 'Enjoy the Journey'
¶;√€...
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