Very Low Predicted pH

[Soay4699]

Hi

I have a recipe that according to the calculator on Brewer's Friend is going to give me a mash pH of 4.68.

What is the best way to raise this to 5.4?

I would attach the recipe file but JBK is rejecting the bmsx extention, and the .txt extention and the screen shot is too big. Sod it....

My water profile is Cal 98 Mag 17 Sulp 121.28 Chlr 41.39 CaCo3 139 Nitrate 11.9

Rob.

[Aleman]

Your CaCO3 figure is that Hardness ro Alkalinity. The two things are not the same and only marginally related to each other.

What are your recipe numbers . . . I would guess a high percentage of 'crystal' and darker malts.

You may need to add bicarbonate, yeah sounds counter-intuitive, but without knowing if your CaCO3 figure is alkalinity that would be the first thing that needs to be checked, Use a Salifert Total Alkalinity test kit.

In my case I would make up a small amount of the grist (say 100g) add 250g of water, and mash for 10 minutes then check the pH with a calibrated pH meter. That way you know what the real mash pH is not what some predicted value may more may not be.

[Eric]

Something is wrong.
With 98mg/l calcium and 17mg/l magnesium, hardness will be around 315, suggesting the figure of 139 refers to alkalinity. However, that doesn't seem be enough to produce a balanced water profile.
All said, I would have expected a much higher mash pH than that you quoted, with most if not all grists, in water anything like that described, although I don't have experience of using software to predict such outcomes.

[Soay4699]

You are correct Eric, the CaCo3 I quoted was for alkalinity.

My grist is 80.5% Maris Otter, 4.6% Caramunich II, 4.6% Choc, 4.6% Crystal, 4.6% Roasted Barley, 1.1% Black.

Is all right to add bicarbonate and chalk to the mash just after dough in, running the pump and taking pH readings until I get it back up to around 5.4?

[Eric]

You are correct Eric, the CaCo3 I quoted was for alkalinity.

My grist is 80.5% Maris Otter, 4.6% Caramunich II, 4.6% Choc, 4.6% Crystal, 4.6% Roasted Barley, 1.1% Black.

Is all right to add bicarbonate and chalk to the mash just after dough in, running the pump and taking pH readings until I get it back up to around 5.4?

If those figures are anywhere near right, the problem you have is the opposite.
I don't use any software, get the alkalinity low enought to be of the right order, have enough calcium present at each stage to deposit all necessary to leave behind, with enough left for the yeast and the pH doesn't matter, except that it actually be where it should. There is no magic pH number, just a range outside of which a beer will not be as it should.

Few beers will need alkalinity as high as 139mg/l as CaCO3 and you certainly don't want to sparge with such alkaline water. I would expect a pH probably about 5.8 with that grist and water. I'll have to have a go with that calculator as I can't accept that prediction.

[WallyBrew]

You are correct Eric, the CaCo3 I quoted was for alkalinity.

My grist is 80.5% Maris Otter, 4.6% Caramunich II, 4.6% Choc, 4.6% Crystal, 4.6% Roasted Barley, 1.1% Black.

Is all right to add bicarbonate and chalk to the mash just after dough in, running the pump and taking pH readings until I get it back up to around 5.4?

Assign the chalk to the bin. Whilst in theory it should work, because it is insoluble in water, you are relying on a weakly acidic solution to dissolve lumps while at the same time generating an insoluble calcium phosphate layer around these same lumps.

I would agree with everything Eric has said and he does brew some exceedingly good dark beers whilst dealing with a variable water supply that at times is not so different from yours.

Alemans advice of carrying out a trial mash is sound. Why would you want to place so much faith in a calculator for a mash pH?
If you were to do this you would be laying the foundations for your own records and gain a feeling for what does affect your mash.

EDIT I was in the process of typing this when Eric replied and again I would say that Eric is making perfect sense

[Eric]

Well I've just tried that calculator with a very rough interpretation of the grist and it gives a mash pH of 5.85 with a typical 23 litre brew with 4kg of base malt and half a kg of darker and crystal in 2.5 litre per kg.

[Aleman]

Eric and Neil (WallyBrew) are on the money. With your grist and water profile, I would expect a mash pH around 5.8, drop the alkalinity down to 75mg/l using an appropriate acid, for a dark beer I would go with 2 Molar Hydrochloric, and you will end up with a real pH in the appropriate range (5.2-5. . . . plus using hydrochloric will increase chloride ions which will help round out the malt profile of a dark beer.

[Soay4699]

Hi

I decided to brew something different yesterday and put the Young's Chocolate on hold until I can get a better understanding of what is going on. I did a Adnams Broadside which I had had problems with before when I last tried it but this time all went extremely well. I hit my target pH of 5.4 and the brew was bubbling away within a few hours of pitching. With my previous attempt I had not correctly adjusted the water resulting in a pH of 5.8 and I under pitched. The beer tasted vinegary. I have learnt alot since then and have not so far produced another dud.

Right, back to my troublesome stout. Here is brewer'sfriend prediction of a 4.7 pH http://www.brewersfriend.com/mash-chemi ... id=X9PVJSP so I am surprised at all your predictions of 5.8 etc without adjustments. And here is my recipe https://www.dropbox.com/s/ig4govtz2e9s3 ... .bsmx?dl=0

[Matt in Birdham]

You've got roasted barley in as a base malt @ 453 L. Changing that to "roasted" and your mash ph goes to 5.62

[Jocky]

Why is that? What's the difference between a base malt and a roast malt when it comes to pH?

[Aleman]

Roast malt supplies more acidity than pale (base) malts

Crystal malts provide even more than Roast malts

[Matt in Birdham]

Why is that? What's the difference between a base malt and a roast malt when it comes to pH?

I suspect it's just a glitch in the calculator, which just doesn't know what to do when a "base malt" of such dark colour is specified. Perhaps they have a calc that works for the narrow range of normal base malts (like, up to 12L or so), but don't error check when 450L is input so you get a ridiculous final value.

[Soay4699]

You've got roasted barley in as a base malt @ 453 L. Changing that to "roasted" and your mash ph goes to 5.62

Well spotted Matt. I am old so have the right to being stupid.

I did a Midnight Stout recently with no problems and that had nearly half a kilo of roasted barley. I must be more careful.