Water Chemistry in bigger batches

I'm wondering if there is something about the scaling of the recipe. Might be worth putting the same recipe into two different recipe apps and see what they say about bitterness, water additions etc.

Just thinking is it possible that minor variations in the 23L batch don't manifest into the flavour but double those variations and your tasting it (appreciate that it's double the volumes also etc....)

Higher boil pH aids hop utilisation. If your boil pH measurement is correct, that would explain the bitterness. High pH is also bad for the microbial stability in beer.

As to why your pH is high, I'm wondering how you adjust your water pH and if there's an issue with mixing, dispersal in the larger volume? If your adding to the mash, rather than treating liqour.

pH should go up slightly during sparging.

Scaling your batch size should not affect water chemistry.

I think more likely is that either you’ve scaled the recipe incorrectly or there’s some difference in the equipment (e.g. boil vigour) that is catching you out.

The post boil pH is very high though - did you get the same with high pH on your smaller equipment?

Can I suggest maybe you post a known good recipe for your 23 litre system, and then post the same recipe scaled up for your 65 litre system. That way we can spot if anything looks wrong in the scaling.

This is an area I feel perplexed by, mostly because I didn't do chemistry at school so and ignorant of it and rely 100% on the calculators. I'm also very unsatisfied about using tap water for brewing, even though I have half decent water, because it changes from day to day. Firstly your water report from your local water supplier doesnt necessarily represent what is actually coming out of your tap..will be kind of representative but not particularly accurate. OK so you can send a sample of tap water away for analysis and get something a bit more precise, but the water changes from day to day/month to month, so again not super accurate unless you're going to sample every single time you brew. I've recently started using RO water from a reasonably local Spotless water station near me and find alot more consistency and improvement in the beer. Also find the PH level are much easier to manage and mostly don't need to take any action to manage ph as the low alkalinity of the RO water compared to my tap water means the PH drops into the zone just from acidification of the grain alone.

I guess if you were off with your water chemistry on the smaller scale, then scaling it up is just going to magnify the errors and expose them more readily?

hoppyscotty said:

I guess if you were off with your water chemistry on the smaller scale, then scaling it up is just going to magnify the errors and expose them more readily?

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Not really - everything increases in proportion with scaling the batch. Of course not doing that may be the problem here.

I seem to remember that it’s not linear scaling for hops. Can’t remember which book I got that from.

I don't think it's necessarily water chemistry. That won't change.

I think you can scale a recipe.

What's charged?

The machine..... So the first question is

Did you calibrate it. Do you know the temps are correct? Or more importantly the same as before.

Sorry for no replies been out golfing all morning, I never do any water additions on my 30 litre setup and never really had a problem always kept ph at 5.2/5/4. Only thing that's changed is the new machine. And new 55l fermenter. temp seems to be holding well. I never had a built in pump before so used to recirc with a jug every now n again. Now I run the pump for last 30 mins of mash. I've used Brewfather app to scale my recipes. Tweaked boil off rates in the equipment profile to what I learned from the first brew. I'm thinking the bigger sparge water amount is creating too many tannins but the no sparge batch did exact same.

Well you can track your sparge water by measuring the running and stopping sparging before it hits 1.012 gravity or ph of 6 or high 5's as either of those can pull tannins...also don't heat your sparge water ro above about 75 degrees or so to avoid pulling tannins too.

hoppyscotty said:

Well you can track your sparge water by measuring the running and stopping sparging before it hits 1.012 gravity or ph of 6 or high 5's as either of those can pull tannins...also don't heat your sparge water ro above about 75 degrees or so to avoid pulling tannins too.

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New ph meter come today and phosphoric acid for lowering ph so another brew Sunday see if I can get this bigger batch mastered. If not I'm gunna av a few month off to reset.

Calibration?

I don't think "bitter to undrinkable" is water chemistry.

You seem set on pH, but I can't help but this this is a basic somthing.

Have the checked the recipe manually?

What else has changed?

Are the mash temps correct, I had this recently with a newbie.. Trusted recipe, similar kit, simile water. Calibration off by 2-3°c caused very poor beer.

MashBag said:

I don't think "bitter to undrinkable" is water chemistry.

You seem set on pH, but I can't help but this this is a basic somthing.

Have the checked the recipe manually?

What else has changed?

Are the mash temps correct, I had this recently with a newbie.. Trusted recipe, similar kit, simile water. Calibration off by 2-3°c caused very poor beer.

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Not really checked it extensively but Checked mash temp with a thermometer and it seemed close enough. Maybe give it a better check next brew. What would cause bad results? low mash temp or higher mash temp? Cheers

MashBag said:

I don't think "bitter to undrinkable" is water chemistry.

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Certainly, look elsewhere, but pH is massively influential in beer quality and needs addressing regardless.

"Some of these benefits. [Kunze, 2007]:

• The enzymatic activity in the mash is increased as all important enzymes get activated. (except for alpha amylase which starts to suffer at a pH below 5.6)
• More zinc, an essential yeast nutrient, goes into solution
• The extract yield (efficiency) is improved
• The protein coagulation and precipitation is improved (improved break formation)
• The redox potential is improved which results in a lower susceptibility to oxygen.
• The run-off speed is improved
• The color increase during the wort boil is reduced
• Better trub precipitation and faster pH drop lead to faster fermentation and greater attenuation of the beer.
• Lover viscosity improves filterability
• The taste of the beer is more rounded, fuller and softer. The beer is crisper, more fresh and shows more character.
• The hop bitterness is more pleasant and doesn't linger
• The foam is more stable and denser
• The color of the beer is lighter
• Mash oxidation is reduced since the main culprit, the lipoxigenase enzyme, doesn't work well at low mash pH conditions
• Haze stability is improved
• Beer digestion is stimulated. This is a positive effect of the lactic acid
• Susceptibility to microbial spoilage is reduced through
  • Lower beer pH: beer spoilage organism don't grow below a pH of 4.4
  • Higher attenuation"

The utilisation of the α- acid humulone ramps up dramatically as pH increases. Extraction quadruples between 5 and 6 pH at 100°C.


The solubility of various hop alpha acids based on temperature and pH. This chart was taken from [Briggs, 2004]

Absolutely agree.
In this instance we are looking for what's changed.
If the ratio between the same water and the same grain is constant maybe it gets a free pass for the moment.

The tin has changed, which impact temp and pumping.
Temperature is a fundamental to brewing.

Fezzer said:

What would cause bad results? low mash temp or higher mash temp?

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The first couple of brews I would write off to cleaning, seasoning, understanding & passivation.

A couple of degrees off will affect the outcome.

Good or bad is taste and this subjective. If you are expecting tea, coffee testes awful.

Have you changed anything else?

OK next question.

What 23l system did you have, and what have you upgraded too?

The secret is in the detail.

Can you also share a recipe that works and the same, scaled that does not?

Fezzer said:

I'm thinking the bigger sparge water amount is creating too many tannins but the no sparge batch did exact same.

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When a full volume brew and a sparged brew both have the same problem, this indicates there is too much alkalinity and not enough buffering capacity.

It looks to me that the issue with AIO's is when removing the grain basket, you remove almost all of the buffering capacity from the grain to be sparged. Except for the 1L/Kg of grain absorption.

I suspect the 30L system has a closer, lower ratio of sparge volume (untreated alkalinity) to liqour held by grain absorption (buffering capacity). The 65L system having a higher ratio that is extracting more tannins and adding more unbuffered liqour to the boil, raising pH.

MashBag said:

OK next question.

What 23l system did you have, and what have you upgraded too?

The secret is in the detail.

Can you also share a recipe that works and the same, scaled that does not?

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I had the 30l klarstein just basic kettle and upgraded to 65l klarstein with recirc pump. I've changed from an immersion chiller to a counterflow chiller. This is my fave 23l batch recipe I do in my 30l klarstein it says its in my 65l at top under equipment but it was in the 30l kettle. https://share.brewfather.app/JzztxffXHfAMOO. Not got the scaled version has I changed it back to 23l when it turned out different. Will you scale it for me and resend it back and I'll try that version. I scaled it to get 46l has my fermzilla loses 2 litre and I use a big 11 gallon keg. Other thing I noticed is brewfather said 4 packs of yeast in big batch but I only used 2. sure 2 packs of yeast is enough for 46l have I been under pitching and the big batch is stressed??