Contradictory pH results in Brewer's Friend Calculator

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
Post Reply
MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Contradictory pH results in Brewer's Friend Calculator

Post by MTW » Sat Mar 02, 2019 4:51 pm

Anyone familiar with the "Brewer's Friend "Mash Chemistry and Brewing Water Calculator" may be able to help with this. [If you've got a saved record on there, maybe even see if it does the same as mine.]

When I enter the grist info by the percentage of predicted beer colour that is calculated to come from the roasted grains, rather than entering each component of the grist more precisely, it yields a very different pH result for the same mash. It predicts 5.4 by roast colour only, and 5.6 with full grist info, for my recent stout. The stout prior to that gets a result of 5.2 by roast colour and 5.4 by full grist info, with the salt additions I had entered. They're quite big differences. I only have maltmiller narrow range pH strips to test with on the day, not a meter, and if I were to believe the test I did (10 mins in, cooled sample), then my recent stout was closer to the colour-only prediction (actually, perhaps lower still than the 5.4 predicted; certainly not the 5.6 predicted by the full grist input).

You'd think that giving BF more information, with the full grist, would yield a more accurate prediction, though that's not backed up by what I may have found. The fact there is such a difference in the two predictions anyway seems odd. I entered the grist as accurately as I could, though I had to count oats as a base malt, due to the limitations of the options on that section. I don't imagine that affects it much. With the roast-colour input, I noted the predicted beer colour in my software, zeroed the roasted grains, and calculated the percentage the roasted grains must have contributed to the colour from the difference.

Anyone use this calculator and tests the actual mash?
Busy in the Summer House Brewery

Silver_Is_Money
Steady Drinker
Posts: 48
Joined: Thu Sep 13, 2018 2:35 pm
Location: N/E Ohio, USA

Re: Contradictory pH results in Brewer's Friend Calculator

Post by Silver_Is_Money » Sun Mar 03, 2019 1:02 am

pH strips are simply not known to be very accurate at all. And particularly more so in media which contributes its own color. That said, I agree with you that the (now relatively aged) Kai Troester (Braukaiser) based color only section of Brewers Friend seems to offer lower mash pH predictions than the more modern grist component method that it employs (and for which I do not know who's math model methods are being utilized). I also agree that the lower pH predictions of Kai's older method seem (based upon my mash pH measurements) to be more accurate. Unless there have been changes to the Brewers Friend website that I'm not aware of, the "color only" mash pH predicting section of Brewers Friend is based directly upon Kai's original calculator known as the "Kaiser Water Calculator", which is still available (or was last time I checked) as a free download on the internet, and which runs within a spreadsheet.

But as the developer of 'Mash Made Easy' I must admit that I'm fully biased toward thinking that my own spreadsheet (particularly its latest version 5.60 release) based mash pH assistant tool is quite accurate in its own right. Mash Made Easy is free and complete, and is available as an internet download.

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Contradictory pH results in Brewer's Friend Calculator

Post by MTW » Sun Mar 03, 2019 4:26 pm

Very grateful for that info.

I ran the recipe through your MME calculator. It would seem to concur with the lower prediction for my recent stout, ie the one generated by putting the roast colour only into the BF calc. To hit a mash pH of 5.4 with the salts I added, MME generates a requirement of 0.52g baking soda; I added 1g, which I assume is near enough to be within tolerance limits. [If I increase the alkalinity of the source water by 10ppm, it switches to requiring a touch of acid, so it must be very close.]

The higher prediction (from entering full grist into BF] certainly didn't seem right to me; it required me to add enough acid to reach a level of CACO3 that I would consider normal for a far paler beer, for a 5.4 mash.
Busy in the Summer House Brewery

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Contradictory pH results in Brewer's Friend Calculator

Post by MTW » Sun Aug 11, 2019 3:37 pm

August 2019 - Bit of a follow up and a new question.

Brewer's Friend is suggesting a target strike alkalinity that is much higher than I would expect for an ordinary bitter. We resolved (above) that the 'beer colour' only feature of the BF calculator produces a lower mash pH estimate than when you take the option to enter a full grain bill. But can it really be true that I can get a mash pH of 5.35 with strike water at 90ppm CACO3 in an ordinary bitter? Especially seeing as my Klarstein's 8L deadspace under the basket means a grist to liquor proportion of 4.7L/Kg? There's 2% chocolate malt in it, but no other roast or acid malt, though 60% of the beer's estimated colour of 13.2 SRM does come from that chocolate malt.

I can't seem to use the MashMadeEasy calculator to check; it asks for a password to enter the alkalinity in the first box, and I can't find reference to one anywhere.
Busy in the Summer House Brewery

User avatar
Jocky
Even further under the Table
Posts: 2232
Joined: Sat Nov 12, 2011 6:50 pm
Location: Epsom, Surrey, UK

Re: Contradictory pH results in Brewer's Friend Calculator

Post by Jocky » Mon Aug 12, 2019 2:20 pm

What's your particular worry about the pH? Poor efficiency or something else? If you're serious about measuring efficiency then bin the pH strips and get a pH meter that you can calibrate.

Personally I tend to eyeball the alkalinity for any particular beer depending upon the grist, measure the resulting mash alkalinity and take notes to adjust the next time I brew the recipe. I've not had a lot of success with pH predicting calculators.

For an ordinary bitter I'd go 30-60ppm (EDIT: I changed this from 60-90, sorry I had a brain fart with the previous value as I was thinking about brewing porters at the time...), but I'd certainly be at the lower end of that if using a high liquor to grain ratio.
Last edited by Jocky on Tue Aug 13, 2019 9:27 am, edited 1 time in total.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Contradictory pH results in Brewer's Friend Calculator

Post by MTW » Mon Aug 12, 2019 9:19 pm

Thanks Jocky - great help in the last sentence there. Graham Wheeler's calculator (in the Extras section on here) wants carbonate down to about 25ppm CACO3 (15ppm CO3) for a bitter, if I've understood his target profile correctly. Even for a porter and stout, his target profile only goes up to 83pppm CACO3 (50ppm CO3). I'm glad the figures I'm getting in the calc are in the range you quote, and I did go on the lower side of that, with a calculated 68ppm in the end.

I just want to get the pH in the right zone, and make it repeatable, which means working from some sort of basis. I've always preferred to put the effort into decent calculations/estimations, rather than work with (even a decent) pH meter, as they sound a bit of a faff! Are they really accurate enough to beat well-worked calculations, at least in achieving consistency? I don't use the strips any more.
Busy in the Summer House Brewery

User avatar
Jocky
Even further under the Table
Posts: 2232
Joined: Sat Nov 12, 2011 6:50 pm
Location: Epsom, Surrey, UK

Re: Contradictory pH results in Brewer's Friend Calculator

Post by Jocky » Tue Aug 13, 2019 9:36 am

First of all, I should apologise and say that my alkalinity recommendation was off - 30-60ppm alkalinity as CaCO3 would be more like it for a bitter. For some reason I had porter on the brain at the time.

To address your last point first - from experience, mash pH calculators tend to have three weaknesses - high % roasted malt grists, high alkalinity liquor, high liquor to grain ratios. Any of those three tends to throw off the predictions for pH. A pH meter does not predict, it gives you an objective measurement of the value, and honestly I find using one way less of a faff than any of the water calculators.

As for getting pH in the 'right zone'... the *working* range for mash pH is massive - most UK tap water will produce a working mash pH when untreated. Yes, there is an 'optimum' range for mash pH, but if you're not seeing any issues with conversion or astringency in your beer then you're close enough, and any improvements are going to be subjective improvements in beer flavour/mouthfeel that you need to experiment with, and without a pH meter you are slightly flying blind.

I know what alkalinity I prefer to use because I have measured my mash pH many times, compared it to my brewing/tasting notes and have come up with a personal preference for what values to use and when. Ultimately it depends upon your kit and what you are brewing. If you're not willing to do the same then I'd say you should concentrate elsewhere in your brewing as there are many more important gains to be made in areas such as improving fermentation and avoiding oxidation.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Contradictory pH results in Brewer's Friend Calculator

Post by MTW » Tue Aug 13, 2019 12:40 pm

I think it's only a matter of time before I get a good pH meter, to be honest. It's just never been the next £50 or so I've wanted to spend, when a lot of (mainly American) brewers seem to report accurate predictions with their favoured calculator.

I think the reason I've posted again now about this, is that *if* the BF calculator (in beer SRM/%age roast-colour mode) were to be correct in its seemingly high CACO3 profile figure, even with my thin mash, then it would mean that other calculators (like GW's) have been leading me astray in previous brews - even taking me below a working range, ie below 5.2pH. There are enough variables in my brews that I can't be sure that anything slightly off the mark has come from this, and many are fine. Moving to a Klarstein machine (and 8L deadspace = thin mash) has meant some re calibration of my process.

But I get it; get a meter, then I will know!

I had some astringency in the last brew, but it only appeared after a modest dry hop when FG was already very stable, and was sampling fine until then.
Busy in the Summer House Brewery

User avatar
Jocky
Even further under the Table
Posts: 2232
Joined: Sat Nov 12, 2011 6:50 pm
Location: Epsom, Surrey, UK

Re: Contradictory pH results in Brewer's Friend Calculator

Post by Jocky » Tue Aug 13, 2019 2:21 pm

I think that you tend to hear people crow about pH calculators when they're right, but not so much when they're wrong. It's also a bit of a case that it's like having a spreadsheet that predicts the sun will come up tomorrow morning - if you have a mostly pale mash and use liquor with low to moderate alkalinity you're probably going to be in the right pH zone.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

Post Reply