Add Minerals to Sparging Water or the Kettle?

A popular question regarding brewing water mineral adjustments is whether to add those minerals to the sparging water or reserve them and add them to the kettle.

As most brewers know, if you want a certain water profile, you will need to add minerals in proportion to the total water amount used in your brewing session. The question is when to add those minerals? For the mashing water, we generally will add minerals to that water since they often have an effect on pH. For sparging water, some brewers reserve the mineral additions calculated for that sparging volume and add them directly to the kettle. Here is why that may not be the best approach.

For brewers using water with little mineralization, there is a clear advantage to adding calcium salts to the sparging water. The extra mineralization added to the sparging water provides a couple of benefits. The first is that the increased osmotic stress on the cells of the grain from the higher mineralization should help reduce the extraction of undesirable components like tannins and silicate from the grain. Another benefit is that extra calcium in the sparging water helps complex with oxalates from the grain and helps keep them out of the kettle. So these are benefits from increasing the sparging water mineralization.

Now there is a drawback to adding calcium salts to the sparging water. The calcium ends up complexing with phytins from the malt. Some of that calcium is lost in the mash, but that is a minor price to pay for the benefits mentioned above. If the overall calcium content of the wort is going to be lower than desired, its a simple thing to add more calcium salts to make up for that loss.

So the message is clear...add the minerals calculated for the sparging water volume to the sparging water and not into the kettle.