Hi folks
So all of my beer's lately are not getting below fg 1.025. I am using a variety of different yeasts different beer style's. Aerating the wort before pitching, watching fermenting temps, og are correct and ph checking correct.
Has anyone got a clue what this means or have an experience like this
Check you hydrometer in some water to make sure its not the problem. Should read 1.000 at room temperature
Quote from: delzep on August 16, 2015, 12:35:12 AM
Check you hydrometer in some water to make sure its not the problem. Should read 1.000 at room temperature
+1
Should read 1.000 in distilled water at 20 celsius if you want to be really spot on but tap water at 20C is close enough. Check what temp it says on the hydrometer but most are calibrated at 20 degrees.
What temp are you mashing at? too high will leave more unfermentable sugars/dextrins in the wort which will give a higher FG.
Could it be that your strike water is too hot and is denaturing your mash enzymes before they get started? This might also be caused by an innaccurate thermometer.
you've also got to think about the temp changes when you add a load of hot water at 70+ C to grain at 15 to 20 C. The temp change is not uniform and some grain will hit much higher temps from the initial contact with the strike water than the rest which will kill the enzymes. This is something that took me a while to get right but i've figured out that heating my strike water to 10 C above my desired mash temp gets me fairly close as long as I add the grain and water together slowly enough to let the temp settle evenly rather than filling the MT with grain and dumping all the hot water in on top in one go.
Hope this helps but be aware that im just typing out loud and its very late :)
Quote from: Drum on August 16, 2015, 02:26:07 AM
Quote from: delzep on August 16, 2015, 12:35:12 AM
Check you hydrometer in some water to make sure its not the problem. Should read 1.000 at room temperature
+1
Should read 1.000 in distilled water at 20 celsius if you want to be really spot on but tap water at 20C is close enough. Check what temp it says on the hydrometer but most are calibrated at 20 degrees.
What temp are you mashing at? too high will leave more unfermentable sugars/dextrins in the wort which will give a higher FG.
Could it be that your strike water is too hot and is denaturing your mash enzymes before they get started? This might also be caused by an innaccurate thermometer.
you've also got to think about the temp changes when you add a load of hot water at 70+ C to grain at 15 to 20 C. The temp change is not uniform and some grain will hit much higher temps from the initial contact with the strike water than the rest which will kill the enzymes. This is something that took me a while to get right but i've figured out that heating my strike water to 10 C above my desired mash temp gets me fairly close as long as I add the grain and water together slowly enough to let the temp settle evenly rather than filling the MT with grain and dumping all the hot water in on top in one go.
Hope this helps but be aware that im just typing out loud and its very late :)
My hydrometer is calibrated with distlled water at room temp and reads correct.
My mash temp is between 72 and 75 degrees C to hit my desired mashing temp usually between 64 and 67 degrees C. This seams to work for me, I put the water in mash tun and then dump in grain as fast as I can to get all the grist to the right temperature for the conversion to begin
Your process up to dough in sounds fine. Working forward, have you ever done an iodine test at mash out to test for conversion?
@frequent sequence yeah I do the iodine test and check sparge ph and ph end of the boil.
Lets discuss your yeast. Are you re-hydrating dry or making starters for your liquid yeasts?
What is your pitching temperature.
Are you calculating cell count based on OG?
I am rehydrating yeast package, but not based on og. My pitching temp is usually 19 to 20 degrees
It may be that I have to much unfermentable sugars left after the yeast has done its work ? I dunno but next brew I will try sparging at lower temp.
If you are mashing for 60 mins between 64 and 67 and then sparging it should not be an issue.
I think you should outline your whole process. If anything has changed as you say this is happening lately
Have you calibrated your thermometer? It could be that you are over shooting your temps.
Biggest cause of stuck fermentation is under pitching, what dried yeast are you using, how are you storing it?
Where are you fermenting and what temperature are you fermenting at?
Using a variety S04, S04, Nottingham, maribru 514, Saflager w70 34 all stored in fridge . Pitch rehydrated 12gram pack for 22 ltr batch and fermenting at 20 degrees in this weather its very difficult to control but same cannot be said for my lager fermented in temp controled fridge
There is something we are missing on your yeast health, Nottingham needs hydrating, US05 can be pitched direct.
You need a min of 2 packs of W70/34
http://www.danstaryeast.com/products/nottingham-ale-beer-yeast
Are you sure you are at 19-20 as weather has been very cold up to the last 5 days, can you use a tube heater in your fridge to guarantee 19 degrees?
To help the act of a gentle swirl rouses yeast but I find going into secondary is more effective, no sloshing or bubbles and I use co2 flush in receiving vessel.
I've never rehydrated Notty before and it always turns out fine
The manufacturers instructions would tell us differently.
I have to admit I don't use dry yeast with the exception of Bry97, sprinkling on the top of foamed aerated wort has the same effect as rehydrating I gather and is what I have always done to avoid contamination. The last recipe I did that with using BRY I pitched 2 packs as its notoriously slow.
Quote from: Frequent Sequence on August 16, 2015, 06:03:28 PM
Have you calibrated your thermometer? It could be that you are over shooting your temps.
Yep thermometers are callibrated
Quote from: Ciderhead on August 16, 2015, 09:05:49 PM
There is something we are missing on your yeast health, Nottingham needs hydrating, US05 can be pitched direct.
You need a min of 2 packs of W70/34
http://www.danstaryeast.com/products/nottingham-ale-beer-yeast
Are you sure you are at 19-20 as weather has been very cold up to the last 5 days, can you use a tube heater in your fridge to guarantee 19 degrees?
To help the act of a gentle swirl rouses yeast but I find going into secondary is more effective, no sloshing or bubbles and I use co2 flush in receiving vessel.
didnt know that about W70/34
ok forgetting about lager as its a rats nest and we could start talking about hot or cold pitches etc.
What about your ale ferment temps are you too low?
Quote from: Ciderhead on August 16, 2015, 09:51:54 PM
ok forgetting about lager as its a rats nest and we could start talking about hot or cold pitches etc.
What about your ale ferment temps are you too low?
No not to low, the last two brews were at 20 to 22 ??? Just thinking there my sparge temp has been 84 to reach 77 degrees in the tun , might be getting to many unfermentables at this temp
As others have said,
You need to be happy with the calibration of your instrumentation
The thermometer is handy enough to calibrate and here's a link to calibrating your sacchrometer/ hydrometer
http://hbd.org/deb/HydrometersAndRefractometers.pdf
Simple things spring to mind, does the green beer taste sweet,(pointing back at your saccharometer accuracy) is your base malt actually malt ie not malted wheat etc?
Are you adding too much adjuncts / coloured malts, how old is your malt?
If using lots of adjuncts you need to extend your mash time ?
Is the iodine test showing a full conversion?
Has this problem started with any particular change in either process or raw materials? This is where good record keeping comes in.
I personally always make a yeast starter, as mentioned earlier, under pitching and insufficient aeration would be the next port of call for testing, after this fermentation temperature, try stirring up the yeast on case the yeast has dropped out of suspension due to a temperature drop?
Nine times out off ten this is a yeast or temperature issue Finding the problem is tricky When we have little to go on. What has changed since you started having issues?
I love a good murder mystery novel :), btw we are not here to judge or criticise, just help you and the lurkers brew better beer as others have helped us down the years.
One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue
Quote from: Frequent Sequence on August 16, 2015, 10:38:36 PM
Nine times out off ten this is a yeast or temperature issue Finding the problem is tricky When we have little to go on. What has changed since you started having issues?
Quote from: Sorcerers Apprentice on August 16, 2015, 10:33:27 PM
As others have said,
You need to be happy with the calibration of your instrumentation
The thermometer is handy enough to calibrate and here's a link to calibrating your sacchrometer/ hydrometer
http://hbd.org/deb/HydrometersAndRefractometers.pdf
Simple things spring to mind, does the green beer taste sweet,(pointing back at your saccharometer accuracy) is your base malt actually malt ie not malted wheat etc?
Are you adding too much adjuncts / coloured malts, how old is your malt?
If using lots of adjuncts you need to extend your mash time ?
Is the iodine test showing a full conversion?
Has this problem started with any particular change in either process or raw materials? This is where good record keeping comes in.
I personally always make a yeast starter, as mentioned earlier, under pitching and insufficient aeration would be the next port of call for testing, after this fermentation temperature, try stirring up the yeast on case the yeast has dropped out of suspension due to a temperature drop?
The only thing that has changed is I started adding mineral salts . I use Bru n water to calculate this and beer smith for my recipes. My water is our own well water which is very low in minerals
( TDS reading of 62ppm) All my instruments are calibrated checked on brew day so I am happy with that. I am not useing a lot of adjuncts, my malt stock is small as in I order fairly often, don't have grain stiiing around for months. My Iodine tests are coming up trumps.
What is the ph of your water pre-treatment?
Also with water with low ppm you may have to add yeast nutrients.
Can you give us the last 5 batches OG and FG.
We will try and get to the bottom of this predicament for you :)
Quote from: hassettbrew on August 16, 2015, 05:09:22 PM
It may be that I have to much unfermentable sugars left after the yeast has done its work ? I dunno but next brew I will try sparging at lower temp.
Minimum temp of sparge should be 78c any lower can cause run off issues, at this stage all conversion has been done, lower temperatures can cause gumming up of the grain bed due to glucans in the grain
Try a brew without salt additions to see if this resolves the issue ?
Quote from: Sorcerers Apprentice on August 16, 2015, 11:30:03 PM
Minimum temp of sparge should be 78c any lower can cause run off issues, at this stage all conversion has been done, lower temperatures can cause gumming up of the grain bed due to glucans in the grain
Try a brew without salt additions to see if this resolves the issue ?
Lower sparge efficiency will only cause efficiency issues, not lowerOG to FG. Unless I have missed something.
Exactly, the sparge temp will only effect the run off speed
Quote from: Frequent Sequence on August 16, 2015, 11:15:54 PM
What is the ph of your water pre-treatment?
Also with water with low ppm you may have to add yeast nutrients.
Can you give us the last 5 batches OG and FG.
We will try and get to the bottom of this predicament for you :)
Ph pre-treatment is 6.5 usually
OG 1.048 FG 1.025 MUNICH HELLES
OG 1.045 FG 1.023 STOUT
OG 1.059 FG 1.024 AMERICAN AMBER
OG 1.059 FG 1.033 APA
OG 1.054 FG 1.028 PORTER
My beers still taste good ( if I might say so meself ;) despte lack of alcohol :'(
Quote from: Sorcerers Apprentice on August 16, 2015, 10:49:39 PM
One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue
This sounds like a great thing to try that will at least rule out your brewing technique vs fermentation technique.
Quote from: molc on August 17, 2015, 08:39:01 AM
Quote from: Sorcerers Apprentice on August 16, 2015, 10:49:39 PM
One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue
This sounds like a great thing to try that will at least rule out your brewing technique vs fermentation technique.
There are lots of sites giving advice on Forced Fermentation Testing eg
http://www.hungusbrews.com/2015/02/20/how-to-perform-a-forced-ferment-test/
Quote from: Sorcerers Apprentice on August 16, 2015, 10:49:39 PM
One other thing that springs to mind is a Forced Fermentation Test, take a sample after pitching and keep it warm ~ 30c on a stir plate this should show in about 24 hours your potential final gravity, if this is high then it's a brewing issue if it's low then you have a fermentation issue
I will deff try this, thank you
Hi,
I know you said you calibrated your hydrometer but by any chance, have you been using a refractometer for checking your FG?
Just a random thought but that would explain the readings (Assuming the beer tasted "as expected/planned").
Good luck with the investigation!
@jay dee..that would explain a lot
@ hassetbrew, if u are using a refractor without doing a recalc on beersmith tools then ur beers are prob about 1010fg also beer at 1025 would taste quite sweet
@jay dee :-[ yes that does indeed explain a lot ... live and learn eh
Glad that helped.
I'd say it happens to a lot of people when they switch to the refractometer.
Good luck with future brews.
I made the same mistake in the past but my assumption was different. I had a hyrometer as well to get a more believable reading so just assumed my cheapo Chinese refractometer was rubbish.
Great things refractometers once you know what their limitations are, even ones off Aliexpress
I'd say the chinese manufacturing gets blamed for many a dodgey brew! ;)
Here's a very handy calculator for refractometer FG conversion:
http://seanterrill.com/2011/04/07/refractometer-fg-results/
@ Jee Dee thanks for that, its a great site too, brew on........
Sean Terrills calc is by far the best and he performed a great experiment getting better actual results than Homebrewers using standard hydrometers, beersmith and others are good too.