Do minerals concentrate with long boil?

Are mineral additions like chloride or sulfate concentrated during the boil?

Should I only add enough minerals for the final volume?

I sometimes brew 1 gallon batches, and the volume at the beginning of the boil is usually 2.5 gallons.... When I brew 10 gallon batches, the beginning volume is 13 gallons. I wonder if the same beer brewed at these different volumes have different mineral concentrations in the final volume?

When I brew 10 gallon batches, should I try to achieve my target mineral concentration at the end of the boil, or should I add the target mineral concentration to the mash and sparge water?

I'd guess that everything except hydrogen and oxygen are concentrated during the boil. So yes, add for final volume. I really hope one of the smart guys will jump in here and add some knowledge to my conjecture

To some extent you are correct, boiling will concentrate the ions. But in general the volume reduction during boiling should not be enough that ion concentrations should be calculated for post boil volume.

Kai

hopdoc said:

Are mineral additions like chloride or sulfate concentrated during the boil?

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Distilled water is 'pure' because when water is boiled the minerals stay in the water. It is the same with your beer. Whatever you put in the kettle before or during the boil will be there at the end (for the most part).

hopdoc said:

Should I only add enough minerals for the final volume?

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You should add as much as makes the beer come out to your liking.

hopdoc said:

I sometimes brew 1 gallon batches, and the volume at the beginning of the boil is usually 2.5 gallons.... When I brew 10 gallon batches, the beginning volume is 13 gallons. I wonder if the same beer brewed at these different volumes have different mineral concentrations in the final volume?

Click to expand...

Use conservation of mass (the first paragraph) to figure that out.

hopdoc said:

When I brew 10 gallon batches, should I try to achieve my target mineral concentration at the end of the boil, or should I add the target mineral concentration to the mash and sparge water?

Click to expand...

Most everything goes straight through so it doesn't matter where you add it. The exception is calcium. Some calcium precipitates with malt phosphate which both reduces calcium (obviously) but also releases protons which many brewers rely on to partially acidify mash and kettle wort. So where you add calcium salts depends more on how you want to manage pH control.

I've never heard of a 'target' mineral level in the fermenter. Most people have ideas as to how much calcium they want for pH control in the mash and distribute it between chloride and sulfate for taste having general ideas as to how much of each should go into the mash water. They then adjust trying to find the amount of each which gives them the most pleasing beer (ratio and total or actual amounts of each). If the beer tastes to minerally reduce both. If it tastes thin, increase chloride. If it tastes thin and harsh reduce sulfate and add chloride,if hops are wimpy add more sulfate .....