Fermentation stopping

[Mbuchananjr]

My 1st batch was a kit. Came out ok. Second batch was all grain. OG 1.060 and FG 1.011. Wonderful beer. Better or as good as any i have bought. Now i have done same reciept 4 times and each time fermentation stopping at 1.030. Local brew shop has been trying to help and even tried my reciept. OG 1.058/FG 1.013. Good beer like my 1st all grain. I tried again and OG 1.058 and stopped at 1.024. Tried everything to get it going again but no luck. Anyone got any ideas on what is happening???

 

[Parrothead1]

What was your mash temp? Do you have temp control fermentation? How do you areate?

 

[IslandLizard]

How do you take your gravity reading, hydrometer or refractometer?
For the latter, you need to use a correction formula to compensate for the alcohol present, or the gravity readings will be inflated (reading too high).

What yeast are you using? Ferm temps?

 

[Mbuchananjr]

Mash temp between 150F to 160F. I do have control temp when needed fermentation temp was between 66F to 76F. Each one a little different. The last one was 72F to 76F. No not using oxygen.

 

[Mbuchananjr]

I use both hydrometer and refractor for OG. (Used both to double check when problem started) Just hydrometer on FG. Us05. Pitched both dry and rehydrated. Made no difference.

 

[Mbuchananjr]

Sorry not really areating. Also using well water. Nothing really different from 1st all grain to last except fermentation temp on each differed a little.

 

[Jag75]

How long has it been in between these brews? Is there a chance your well water has changed enough to effect your yeast fermentation. Did you aerate the first one ?
Maybe you need to do a starter or yeast nutrient.

 

[IslandLizard]

Is there a chance your well water has changed enough to effect your yeast fermentation.

That's a really good point!
Could be the well water, if it's really hard (high alkalinity) or has lots of minerals it can prevent the yeast from dropping the pH to her sweet spot of pH 4.2.

When pitching, the rehydrated slurry and wort should be ideally within 10°F from each other. 5F is even better. That is to prevent formation of 'small mutants' small cells that can't replicate, stunting growth. I'm sure there is some leeway on those, but more extreme differences will result in more extreme side effects.

Did you aerate the first one ?
Maybe you need to do a starter or yeast nutrient.

Dry yeasts may benefit from aeration and (proper) rehydration (the jury is still out on those) but starters are generally not needed.

 

[IslandLizard]

The last one was 72F to 76F.

That's pretty high for US-05. 64-68F is more in line with her specs.
Did the temp suddenly drop a lot? That could stall a fermentation, although US-05 is less likely to be affected, it's a medium flocculator.

 

[Jag75]

Good point on dry yeast Lizard!

 

[chickypad]

Mash temp between 150F to 160F.

That seems like a pretty big range. Is this single infusion? How are you measuring, is thermometer calibrated? If you are really mashing some of the batches in the low 160's maybe that's the reason.

 

[Mbuchananjr]

No change in the well water. Only one of them had sudden change in temp. Funny they are all stopping at 1.030 except this last one. I have done some mead and rice wine during this and they have done ok. The 1st one ferminated around 76F to 79F, was fighting to keep temp down on that one. I did not areate the 1st one. Never have. Only learning now about areation (thought it was bad till recent reading). I added yeast nutrients on the last 2. Hydrated the yeast on the 3rd one. Tried repitching yeast on 2 of then, 1 hydrated and 1 dry to get restarted but no luck. Added yeast nutrient to get restarted and no luck. This is very flustrating. Got to be something i doing. Going to ck with my brew store to see if he areated the one he brewed. He followed all my instructions as how i did mine. But his fermented at 72F.
I am going today to get more grain and try again but may use purchased filtered water and areate after boil and cool down

 

[bracconiere]

Mash temp between 150F to 160F.

i second what chickypad said... 150f and `160f will net a completely different attenuation.... (and if you want to save them, you can also add glucoamylase, gluco NOT plain amylase...)

 

[IslandLizard]

150f and `160f will net a completely different attenuation

And the first 10-15 minutes at 160F more so than the last 30 minutes.

Mash temp between 150F to 160F.

You really need to control mash temps more deliberately and precisely to get more repeatable results.

is thermometer calibrated?

That's essential too.

 

[IslandLizard]

may use purchased filtered water and areate after boil and cool down

Filtered water is not necessarily better than your well. RO water however makes a big difference, it's a blank slate, virtually devoid of any minerals. You can get it from RO machines in supermarkets, Walmart, etc. Bring your own containers. Check the last service date and TDS reading. It should be below 10 ideally, 20 is still pretty decent, 30 acceptable.

Having some idea of your well water composition (a report) is not a luxury, although it may fluctuate depending on source and seasons.

Only aerate chilled wort, right before (best) or right after pitching yeast!

 

[Mbuchananjr]

Had to wait to reply, only 5 posts every 24 hours.
The temperature of the water that I put in my mash tun is around 168° once I add the grain it usually drops it at around 155 I monitor it and for the hour it normally is about anywhere from 150 to 155 this is been the same for all my batches. I sparge with 160 to 165.
The brew shop did not areate on the one they did.
I only put 150 to 160 as a reference point. Depending on the grain temp it determines the temp after adding the grain. All the mashes were within a degree or 2 of each other. Remember the constant factor in fermentation issue is stopping at 1.030 except for the 1st one and the last one.
I am trying again and will areate this time and considering something besides the well water. Thanks for info on the RO water.
Also i check the thermometer with 2 others and it is correct.

 

[IslandLizard]

Had to wait to reply, only 5 posts every 24 hours.

Sorry about the posting limits. You are in the clear now.

once I add the grain it usually drops it at around 155

Do you stir thoroughly, right after adding? Then measure the resulting mash temp before closing up the tun? Does that come out somewhere between 150-155F as you said? Do you make a note of the exact mash temp at that point? It's a strategic brewing data point, and a good reference. When it's between 148 and 155F you still make very fermentable wort. Above 155F you start increasingly limiting fermentability, to the point where you end of with dextrin soup at 162F.

Few more Qs:

1. 5 gallon batches?
2. How much yeast do you use, 1 sealed pouch of US-05?
3. What temp do you rehydrate the dry yeast at?
4. Except for boiled then chilled water, do you add anything else to that?
5. How long has that yeast slurry been sitting there before you pitch it?
6. What's the temp of the yeast slurry at the point of pitching?
7. What's the wort temperature when you add (pitch) the stirred up, rehydrated yeast slurry?
8. Is there anything left behind in that rehydration container, except for a few drops?

Only learning now about areation (thought it was bad till recent reading).

Aeration/oxygenation is indeed bad everywhere in the brewing process, from mash to packaging. Except, right before pitching yeast, which is the only time you should introduce a liberal amount of air/oxygen. In very few cases (e.g., super high gravity beers) an extra O2 dose 12-18 hours later is recommended. For dry yeasts the manufacturers now don't endorse aeration/oxygenation anymore, or even rehydrating. Their reasons for those changes are still unclear. Could be anywhere from updated research and manufacturing to pure marketing, following the easy-peasy paradigm.

What kind of water does your brew shop use?

 

[Mbuchananjr]

I am going to answer your question in the order you ask them. I dont know yet how to do the quote thing, sorry.
Yes
Yes
No
1. 5.5 gallon
2. Yes 1 sealed pouch
3. Only rehydrated on one and on one repitched. All others were dry pitched. Regydrated at 85F
4. No
5. 20 minutes but remember i am main pitching dry
6. Same as the wort. 78F
7. 78F
8. No
I have never aerated except for the batch i did yesterday.
Btw i checked the ph of water prior to mash and is high 7.2. Checked during mash 15 minutes in and was 5.

 

[IslandLizard]

I am going to answer your question in the order you ask them. I dont know yet how to do the quote thing, sorry.
Yes
Yes
No
1. 5.5 gallon
2. Yes 1 sealed pouch
3. Only rehydrated on one and on one repitched. All others were dry pitched. Regydrated at 85F
4. No
5. 20 minutes but remember i am main pitching dry
6. Same as the wort. 78F
7. 78F
8. No
I have never aerated except for the batch i did yesterday.
Btw i checked the ph of water prior to mash and is high 7.2. Checked during mash 15 minutes in and was 5.

To Quote/Reply:
In a browser (probably on phone app too) select (highlight) the text you want to quote, a little gray balloon popup should appear underneath that reads '+Quote | Reply'. Select 'Reply' to reply. Or, to add to your (multiple) quote list, select '+Quote'.

The pH of water means little, it's the buffering capacity (alkalinity) that's important in mashing. Your mash pH dropping to 5 means it's responsive to your grist addition, which is a good sign, the alkalinity is not through the roof. A mash pH of 5.2-5.4 (chilled to and measured at room temps) is recommended.

Everything you answered seems fine, as expected, except it's recommended to pitch yeast at and ferment at much lower temps than your 78F / 72-76F, resp.

Fermenting at high temps yields lots of fusel (higher order) alcohols that simply don't taste good. This is sometimes referred to as creating 'rocket fuel.' Isopropyl alcohol (rubbing alcohol) is a good example of an alcohol that we don't want in our beer. We want to create ethanol, as pure and with as few byproducts as possible.

The higher the ferm temps are above a yeast's recommended range, the more other unwanted byproducts the yeast creates too, not only bad alcohols, other off-flavors and off-aromas too. Saison and Kveik yeasts, for example, are notable exceptions, as they are 'designed' for higher temp fermentations to get into their own.

 

[Mbuchananjr]

Ok thanks
I will let everyone know about the present on fermenting now

 

[Mbuchananjr]

Ok thanks
I will let everyone know about the present on fermenting now

Hey everyone. Looks like every thing may be good. Have not taken FG yet. Fermentation just stopped. Update coming soon and what i did different based on everyones imput