Fred69 wrote:I'm brewing my first parti-gyle later this week and I had a question on how to handle the water salts. I've got some pretty bad water so I've been using RO water and adding the proper salts to get me where I want to be. I've been adding a portion of the salts to the mash and the remainder to the boil kettle (based on EZ water calculator numbers).
I guess I don't understand why people do this. There may be situations where one wants to add additional salts to the kettle e.g. to finish the boil at a lower pH than would otherwise be realized but it is more efficient to add acids and there will be little further reduction from phosphate precipitation. OTOH one might want additional sulfate for hops bitterness or more calcium for the yeast or, and this is the one that makes most sense to me, some zinc for the yeast. If I read this right you dose up mash water, mash with it and then add more to the kettle. Why not treat all the water at the outset? That's what most brewers do.
The exception to this might be where the water you intend to sparge with is highly alkaline and you fear that it will pull runoff pH over 6. Guess that would be an especial concern in partigyle brewing where you probably would want to extract down to perhaps as low as 2 °P ?
Fred69 wrote:However, with a parti-gyle what do I do? The first running will have the salts added to the mash but do they need to be topped off with the correct proportion based on the extra few gallons of water I'll use to top off those runnings to get the volume I need? And for the second runnings - do I need a whole batch worth of water salts added to the boil kettle (does anything from the mash - second time through - transfer to the second runnings?)?
I'm sure I'm making this more complicated the more I think about it.
As the object of water treatment is primarily to establish proper mash pH it really doesn't matter that much what you do to sparge water unless you fear the potential of tannin extraction. The best thing for you to do, IMO, is just treat the whole brew day's water the same way at the outset. Then you don't have to fiddle with water adjustment during the day and you are assured that everything, mash water, sparge water, makeup water, is uniform with respect to sulfate and choride for flavor uniformity. You should check runoff pH as you progress with the sparge(s) however. If you see pH heading for 6 then add wee bits of lactic or phosphoric acid to the remaining sparge water. Don't add anything in the kettle unless you check pH and decide you want to lower it. In this case, add some acid to the kettle. This is fairly common but few home brewers do it AFAIK.
Now if you want more or less sulfate or chloride in the second runnings than in the first you would have to make separate additions. Assuming you wanted less sulfate in the second, for example (as it is a smaller beer and you don't want so much hops punch) and at the same time want more chloride to round it out you would make up a volume of water sufficient to mash and sparge the first wort. Very unlikely that you would break 6.0 on the first wort unless you have synthezied a rather alkaline water which there would be no reason to do so no acidification of the sparge water would be needed. Now when you start to collect the second wort, dump the remainder of the first batch of sparge water and sparge with another batch which has been treated differently i.e. more calcium chloride and less gypsum than the first.
This is just an example. You'll have to think it through in terms of what you are trying to do. I'd go with the approach of using uniform water throughout the whole process and seeing how the beers turn out. Probably fine and you don't need to do anything beyond preparing the one load of water. If pH does go over 6 on the second runnings to the point where you detect phenol roughness in the finished beer then buy a pH meter and check runoff pH, adding acid to the sparge. In over 20 years of brewing I have never found it necessary to do this but then I have never tried to squeeze that very last bit of extract out either. A liter of 2 °P wort only contains 20 grams of extract.
Finally, if phenols do get extracted they complex and drop out during conditioning. There are few beers that don't benefit from some "lagering". The only downside is that you have to wait.
