Adding Gypsum

[Buzz]

If I plan to add Gypsum to my next brew to help lower the PH (I'm intending to use Gypsum because it's what I've got handy), can I add it direct to the mash or, does it have to be added to the mash liquor and boiled to be of any use

I'm just thinking that, if I have to boil it first, I'm going to have to wait an age for the temp to drop before mashing - the brewday being long enough as it is. If it does have to be boiled, can I do this the evening before and re-heat the water the next morning to strike temp

Thanks in advance.

[Graham]

If I plan to add Gypsum to my next brew to help lower the PH (I'm intending to use Gypsum because it's what I've got handy), can I add it direct to the mash or, does it have to be added to the mash liquor and boiled to be of any use

I'm just thinking that, if I have to boil it first, I'm going to have to wait an age for the temp to drop before mashing - the brewday being long enough as it is. If it does have to be boiled, can I do this the evening before and re-heat the water the next morning to strike temp
Thanks in advance.

You can put it in the mash if that's what suits you better.

If you add it to the water, you are best to boil it in because it's difficult to get it into solution without boiling. The night before is fine. It's what I do.

[Aleman]

The mash will act as a buffer,

FWIW I add all my salts to the dry grist, as Graham says Gypsum can be a tad difficult to get into solution, but when using a slight acid (the mash) it dissolves much more easily. Usually by the time I have got the mash well mixed its done its magic as well.

[Buzz]

That's good to know. I'll add it to the grist tomorrow.

One more question - when taking a PH reading of the mash, is it acceptable to put the test paper directly into the mash or, should some wort be run off and cooled to room temperature for a more accurate indication

[mysterio]

Cooled, heat alters the PH reading.

[tribs]

I've never really understood this. General advice is that a sample should be cooled before testing with pH papers because papers are only accurate at room temp. However the process of cooling is going to alter the pH of the mash liquor anyway. Afterall, the pH of the mash (at mash temp) is what we are trying to measure, correct?.

If this is the case it would seem to me that pH papers would be pretty useless at measuring mash pH, although I do wonder exactly how inaccurate they are at mash temps anyway.

[Aleman]

With a meter temperature is important, it is less so with papers. There is about a 0.3 pH unit difference between room temp and mash temp, personally I dip into the mash and then put the strip on a white porcelain tile, generally it cools quick enough to not be an issue as while the strip is wet the colour change is fluid.

The real problem with a pH meter is that the wort at mash temp is a pretty tough environment for a probe, and I have knackered too many probes, having to replace them about every 6-10 brews (at 90 quid a pop ). If you are using a meter always take a sample of the wort and cool it before measuring the pH