Mineral additions for top-up water

[rajun50]

I am planning on brewing a 10 gallon batch at a higher gravity in my 15gal brew kettle and then adding 5 gallons of top-up water to come out at my desired lower OG and 15 gallon actual batch size (Blonde Ale). I have all my additions figured for the 10gal batch in the Brun Water spreadsheet, but I don't know what I should add or if I should add anything to the top-up water to keep everything like it should be when it's upped to 15 gallons.

I hope I worded that clearly enough. 15 gallon batch brewed on a 10 gallon system. My capacity to ferment exceeds my boil capacity and I'd like to get an extra 5 gallons of wort out of my brew day. I am assuming that I would just add the extra minerals to the kettle as if they were going into the sparge water, but I don't know if that's the right thing to do or not. It will be 100% distilled water built up to spec. as per the Brun Water spreadsheet.

Any insight would be greatly appreciated

 

[mabrungard]

If it is going to be a really hoppy ale and you need sulfate, then supplementing the sulfate in the top-up water is sound. If you are anal-retentive like myself and don't have better things to do with your time, then adding all the ions like in your original water target is OK too. It's not really a big deal either way.

 

[rajun50]

Thanks!