Water Chemistry Increasing Unfermentable Sugars?

[Fat Bastard]

Ok, so I've had a spate of beers finishing over the expected FG. I've tracked down at least part of the puzzle to having bred a lazy streak into the yeast over 4 generations or so, which I deduced by adding some dry yeast to a batch of American Amber Ale which had finished at 1.024 against an expected 1.018 from the last batch. The new yeast dropped it to 1.022, where it remained,which is still way off the expected.

I've cross checked the refract' readings with a hydrometer, and got much the same.

Now I've made a couple of changes to the water chems with this brew. I've removed the MgSo4, and bumped up the CaCl and CaSo4 (aiming for a neutral balance) and added some acidulated malt to the grist to get it back into the range according to EZ Water, which is common to my last few brews that have remained stubbornly over the FG.

I don't own a pH meter and I really only guesstimate the mash pH with EZ water. The first few brews I checked with strips and found it to be near enough and haven't checked it since.

I'm brewing again this weekend, with a brand new vial of yeast, which will be made into a 2 litre starter. Do you think either the removal of the Mg So4 or addition of the Acidulated Malt have something to do with the high FG? I'll be monitoring the mash pH this time with a meter I've nicked from work (a cheapie with only 7.0 buffer to calibrate) and some colourpHast strips.

Tips and advice on using wither of these greatly appreciated!

Cheers,

FB

 

[manticle]

If calcium amounts are appropriate and pH is good, that should aid yeast activity, not inhibit it.

 

[jotaigna]

I've said this before, I had 3 beers in a row finishing high (1.020 to1.024) because of a faulty mash thermometer. Once i calibrated the thermometer, FG went back to expected levels.

 

[Fat Bastard]

Yeah, that's what I thought too. Looking back on my notes, I mashed the latest version of the AAA at 52/10, 62/15, 68/45, 72/10, 78/10 which should have made it finish lower than the last one which was 52/10, 68/60, 72/10, 78/10.

Both had the same size starter (from the next yeast generation), same yeast nutrient and same ferment schedule. Only changes made were the mash temps and chems. Given that I got a little lower from the US-05 addition, I think the water chamistry is doing something, unless my mash temps are out, which is unlikely given I obsessively check the HERMS return with my stick thermometer.

Edit: Didn't see your post Jotalgna. it'd be pretty odd for the probe in the HERMS and the stick thermo to both go out by the same amount at the same time. The mash temp itself normally lags a bit behind the HERMS output, but the temp measured at the output and the temp measured by the probe are normally within 0.1 or 0.2 of one another.

Weird.

 

[jotaigna]

Ps. I also play with those minerals, acidulated malt and lactic acid ( dialling in the same recipe) and I haven't experienced your issue.

 

[Khellendros13]

Def not the salts, I have the opposite problem and have been using salts in all 3 AG brews so far.

 

[jotaigna]

Puzzling

 

[jotaigna]

Ok, if its not temps(I agree it's unlikely)
do you use yeast nutrient?, mg seems to aid yeast health, and perhaps the yeast was a bit tired and did not get a Mg fix as usual from the mineral change.
Adding the us05 when you did may have not been too effective because there wouldn't be much oxygen left after the first fermentation, masking a yeast health issue
(Shrugs).
Good luck in any case.

Edit: pressed send by mistake

 

[manticle]

**** magnesium.
You want zinc. All grain mash has enough magnesium.

Try again, same everything, new yeast (same strain).

Then do same but add zinc based yeast nutrient.
Then same but increase beta rest.
Then same but increase oxygenation.

Also post the recipe and what's the lowest you've ever hit with the exact recipe?

I'd suggest a yeast or dextrinous malts issue

 

[Fat Bastard]

OK, looks like a yeast issue.
It'll be a while before I want to brew the AAA again, but the brew after next will be my Red IIPA, which exhibited the same problem with the same generation of yeast. The batch before last got down to 1.010, the last finished up at 1.019. Some of that I might blame on subbing 400g of dex for 250ml of D2 Candi Syrup, but not that much!

The only differences apart from the Candi Syrup/Dex have been the addition of acidulated malt, and the subtraction of all MgSo4. The plan for the next batch of this is to make up the difference with 200g of dex and back the grain off to compensate. I reckon if the new yeast brings it within .002 of 1.010, I'll have an answer.

Will report back in a month or 2.

Cheers,

FB

 

[Fat Bastard]

Curious stuff.

I took delivery of a Hanna pHEP5 meter today, and in the course of calibrating it, I measured the local tap water pH.

I got a pH of 6.05, which is 1.5 below the lowest value given by the water analysis for my part of Sinny. I then plugged that value in to Bru'n Water, which gave me a room temp mash pH of 4.4, which correlates with the measurment I got with a strip, which was so low it was well below the 5.0 low end on the strip.

This particular brew has finished higher than the last time I brewed this recipe (it's not the AAA mentioned previously), so I wonder if I have a local supply issue here?

 

[manticle]

Your mash pH is 4.4?

What recipe?

 

[mabrungard]

I assume you have a report for your tap water and are using it in Bru'n Water. A mash pH of below 5.0 is too low. Generally, I've found that mashing with a pH around 5 usually increases the fermentability of a wort. But I have to admit that I've never mashed at a pH as low as 4.4. Maybe that low a pH screws up the enzymatic processes and reduces fermentability???? Bringing the mash pH back to a more desirable range should fix the problem.

 

[mmmyummybeer]

pH 4.4 sounds like you have found the problem

 

[Fat Bastard]

I got a pH of 6.05, which is 1.5 below the lowest value given by the water analysis for my part of Sinny. I then plugged that value in to Bru'n Water, which gave me a room temp mash pH of 4.4, which correlates with the measurment I got with a strip, which was so low it was well below the 5.0 low end on the strip.

Hmm, meausured again tonight and got 8.2, which is above the stated in the report. Possible user error here.

Still, with the latest water results plugged into the old EZ Water calc, I get a mash pH of 5.38. With Bru'n Water, the mash pH is estimated at 4.8! This is using the measured water pH and the resultant bicarbonate and carbonate values entered into the correct fields.

Anyway, this might explain the sour aftertaste this beer leaves. Still it was good enough to get 5th out of the 57 entries in class at the NSW comp!

Is there any value in measuring the pH of the finished beer?

Vanilla Bourbon Porter #2
Specialty Beer

Recipe Specs
----------------
Batch Size (L): 23.0
Total Grain (kg): 7.370
Total Hops (g): 42.00
Original Gravity (OG): 1.075 (°P): 18.2
Final Gravity (FG): 1.022 (°P): 5.6
Alcohol by Volume (ABV): 6.98 %
Colour (SRM): 35.6 (EBC): 70.1
Bitterness (IBU): 25.9 (Rager)
Brewhouse Efficiency (%): 77
Boil Time (Minutes): 60

Grain Bill
----------------
4.800 kg Maris Otter Malt (65.13%)
0.850 kg Munich I (11.53%)
0.500 kg Brown Malt (6.78%)
0.480 kg Chocolate (6.51%)
0.300 kg Crystal 120 (4.07%)
0.200 kg Carared (2.71%)
0.200 kg Crystal 60 (2.71%)
0.040 kg Acidulated Malt (0.54%)

Hop Bill
----------------
22.0 g Challenger Pellet (8.4% Alpha) @ 60 Minutes (Boil) (1 g/L)
20.0 g East Kent Golding Pellet (5.9% Alpha) @ 10 Minutes (Boil) (0.9 g/L)

Misc Bill
----------------
4.0 g Calcium Chloride @ 0 Minutes (Mash)
3.0 g Gypsum (Calcium Sulfate) @ 0 Minutes (Mash)
3.8 g Brewbrite @ 10 Minutes (Boil)
2.9 g Yeast Nutrient @ 10 Minutes (Boil)
3.4 g Calcium Chloride @ 0 Minutes (Sparge)
2.6 g Gypsum (Calcium Sulfate) @ 0 Minutes (Sparge)
10.0 g Vanilla @ 7 Days (Secondary)
390.0 g Bourbon Whiskey @ 0 Minutes (Bottling)

Step Mash 52/10, 67/60, 72/10, 78/10
Fermented at 18°C with WLP002 - English Ale

Notes
----------------
10 minute addition added at flame out
2 x Vanilla beans, spilt, scraped, chopped and soaked in bourbon for 2 days prior to going into fermenter whole .
Left until tastes right.
490ml bourbon added to keg

Mash Schedule 52/10, 67/60, 72/10, 78/10

Recipe Generated with BrewMate

 

[manticle]

Check with mabrungard if you are entering everything correctly. While ez water is easier to use, brun water is more comprehensive. More potential for accuracy but also more potential for user error. Pretty sure he'd be willing to make sure you are entering everything as you should.

Sorry if I've missed it but have you actually measured mash pH that low?

 

[Fat Bastard]

Only with a strip, and it appeared to be off the low end of the scale, so well below 5.0.

 

[QldKev]

Only with a strip, and it appeared to be off the low end of the scale, so well below 5.0.

Tell me you are not using those **** keg king ones.

 

[Fat Bastard]

No, it was a colorpHast one, that the pointy heads in the analytical lab at work loaned me.

 

[Fat Bastard]

Some thoughts on the process today with the pH meter:

EZ water predicted a mash pH of 5.54
Bru'n Water predicted mash pH of 5.2
Actual measured pH was 5.1 15 minutes into the 64 step (52/10, 62/15, 64/45, 72/10, 78/10)

Recipe was a Red IPA I.ve brewed various versions of 8 times now, so I'm familiar with the brew and how it acts, even if adding dex and D2 syrup stuffs up the mash efficiency calcs.

Efficiency was lower than expected with a post boil gravity of 1.072 (should have been 1.076) I may put this down to not using any acidulated malt as per normal when using EZ Water.

Tap water pH seems variable around here with me measuring anywhere between 6.4 and 8.2 over the past 5 days. Today was 7.8, which is right on the lower end of the Sydney Water report for my local treatment plant. I'm not sure if the variation is caused by me, the meter, or Sydney Water.

The yeast used was a brand new vial of WLP-001. This took off like a good one, with a healthy krausen on top, despite the stirplate.Much better than the last few recultured starters.

Final analysis will be a month or two yet, though your thoughts are, as always, appreciated.

Cheers!

FB