ultravista

Recipes 

Can/do you use RO water as is, without any additions?

MNDan

Recipes 

Just RO water without calcium additions will be problematic for mashing. I create different water profiles for my RO system by using various salts, a gram scale & this:

http://www.homebrewtalk.com/f128/ez-water-calculator-3-0-a-261001/

mabrungard

Recipes 

I tasted an American Pale Ale that was brewed with just distilled water and no mineral additions. The end product was clean and without any infection. The aroma was adequate, but the flavor was empty. No real pop to the malt or hop flavors or bittering.

Adequate calcium is probably important for more than yeast performance based on the result above. But supposedly, calcium has no real flavor impact. The other significant flavor components, sulfate and chloride were not present, so it seems fairly clear that appropriate levels of those ions are beneficial. "appropriate" is highly subjective and each brewer would likely have to determine their preferences for those levels in the styles they brew.

So, you can brew effectively with straight RO. But the beer may not be that inspiring.

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Martin Brungard, P.E. D.WRE
Carmel, IN
BJCP National
Foam Blowers of Indiana (FBI)
Brewing Water Information at:
https://sites.google.com/site/brunwater/

ultravista

Recipes 

It looks like I will be better off with spring water then.

JonK331

Recipes 

Are you sure your efficiency problems are water related?

ultravista

Recipes 

Probably not efficiency but off-flavors due to the municipal water source.

rancidcrabtree

Recipes 

Looking at it strictly from a pH standpoint you should have less of a need for 5.2 using RO water (which should be right at 7) than tap water. Most public water utilities are putting out somewhere in the area of 8.5 in order to avoid excessive corrosion in their distribution systems.

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