When to Add Water Additives?

When should you be adding minerals and acids when brewing? Common choices include adding them directly to the mash or to add them to the water prior to adding grain. Here are reasons that they should be added to the water prior to adding the grain.

An important reason is that 'sometimes we just screw things up'. Say you add too much of a mineral or acid? It is much less costly to dump a pot of water than a tun full of mash. Adding the minerals and acids to the water is a kind of a safety factor in case of screw ups!

Another consideration is that by adding those additions to the water first, you can verify that they have dissolved fully and that they are fully distributed in the water by mixing. If minerals and acids are added to the mash, it is more difficult to insure that those components are fully distributed through the mash. It takes a lot of mash mixing to make sure those constituents are well distributed.

An exception is when lime needs to be added to the mash to avoid an overly low mash pH. Adding a dose of lime to water can cause the existing calcium to drop out of the water. Fortunately in the cases when additional alkalinity is needed, there probably isn't much calcium or bicarbonate in that water and the lime addition won't cause additional calcium to drop out. So it's probably not imperative that lime be added only to the mash and not to the water first. So if your water has low Temporary Hardness (aka: low calcium and bicarbonate), then it is not imperative to add lime only to the mash. It is OK to add it directly to the water then!

Add minerals and acids to the water prior to doughing in the grain.