Simonh82
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I finally picked up a decent pH meter, having used the nearly useless pH test strips so far. I brewed my first beer with its assistance last night and despite careful planning my mash pH was way out and I can't make the numbers add up. I wonder if anyone can help me understand what is going on.
The beer was a session rye IPA. I use a BIAB system with 24L of mash water. The malt bill was 2.9kg Maris Otter, 700g of rye malt, 100g Crystal 45L, 50g Special B 200L, 70g, Crystal 15L.
My water had alkalinityof 241ppm as CaCO3, (3.95 meq/L). Using Bru N' Water to target a mash pH of 5.46 I added 0.6g/L 14.4g total of Gypsum and 2.5ml/L 6ml total of 80% lactic acid. As the pH test strips I'd used previously had always suggested a low mash pH i only added 5.25ml of lactic acid initially.
When I took the reading for the mash pH 15 minutes in it was at 5.8. I quickly added about 2ml of lactic acid and this brought it down to 5.72. I then added 1.25ml of phosphoric acid and this brought it down to 5.58.
I don't know why the mash pH stayed so stubbornly high. The only thing I've done differently this time, apart from using the pH meter is that i usually use only phosphoric acid. Does lactic acid degrade over time? I've had the bottle for about 6 months unused.
As an aside I also tested my sparge water. To the 11L of water I had added 6.6g of Gypsum and 2.6ml of lactic acid. This should have got it to 5.5pH but when I tested it was at 6.6,down from 7.6 straight out of the tap. I really don't understand what is going on here.
Any thoughts would be gratefully received.
The beer was a session rye IPA. I use a BIAB system with 24L of mash water. The malt bill was 2.9kg Maris Otter, 700g of rye malt, 100g Crystal 45L, 50g Special B 200L, 70g, Crystal 15L.
My water had alkalinityof 241ppm as CaCO3, (3.95 meq/L). Using Bru N' Water to target a mash pH of 5.46 I added 0.6g/L 14.4g total of Gypsum and 2.5ml/L 6ml total of 80% lactic acid. As the pH test strips I'd used previously had always suggested a low mash pH i only added 5.25ml of lactic acid initially.
When I took the reading for the mash pH 15 minutes in it was at 5.8. I quickly added about 2ml of lactic acid and this brought it down to 5.72. I then added 1.25ml of phosphoric acid and this brought it down to 5.58.
I don't know why the mash pH stayed so stubbornly high. The only thing I've done differently this time, apart from using the pH meter is that i usually use only phosphoric acid. Does lactic acid degrade over time? I've had the bottle for about 6 months unused.
As an aside I also tested my sparge water. To the 11L of water I had added 6.6g of Gypsum and 2.6ml of lactic acid. This should have got it to 5.5pH but when I tested it was at 6.6,down from 7.6 straight out of the tap. I really don't understand what is going on here.
Any thoughts would be gratefully received.
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