Why do most craft brewers use RO water instead of building recipes on local tap water?
Municipal tap water varies in mineral content from city to city and even season to season, making it impossible to brew the same beer consistently without controlling the water chemistry. RO removes 95-98% of dissolved minerals, giving the brewer a near-blank-slate water at 5-15 ppm TDS to which specific minerals can be added in measured amounts for each beer style. Our brewery RO systems include a blend bypass valve so brewers can dial in a target TDS without going to full strip.
What minerals are commonly added back to RO water for different beer styles?
The classic mineral additions are calcium sulfate for dry, hoppy ales where sulfate accentuates bitterness, and calcium chloride for malt-forward lagers and stouts where chloride rounds out mouthfeel. Most recipes target calcium at 50-150 ppm, sulfate at 50-300 ppm for hoppy styles, and chloride at 50-150 ppm for malty styles, with exact ratios driven by the brewer's target flavor profile. AMPAC USA systems give brewers the consistent, mineral-free starting point that makes these additions repeatable batch to batch.
How large of an RO system does a microbrewery typically need?
A 3-barrel brewhouse brewing 4-5 times per week needs roughly 500-1,000 GPD of RO capacity, while a 15-barrel production brewery running daily may require 3,000-7,000 GPD when accounting for brewing liquor, cleaning water, and boiler makeup. Storage tank sizing matters as much as membrane capacity since brew day water demand is concentrated into a few hours. We size brewery systems with at least one day's brewing volume in pressurized storage so the RO unit can catch up overnight.
What pretreatment does a brewery RO system need to protect membrane life?
At minimum, brewery RO systems require a 5-micron sediment filter and a carbon block or catalytic carbon filter to remove chlorine and chloramines before the membrane. Chlorine above 0.1 ppm degrades polyamide RO membranes rapidly, and chloramines are more damaging than free chlorine because catalytic carbon is required to remove them effectively rather than standard activated carbon. AMPAC USA brewery systems include the correct carbon media matched to your utility's disinfection method.
Does RO water affect yeast health or fermentation performance?
Very low mineral content water, below 50 ppm calcium, can stress yeast and cause sluggish fermentation, haze issues, and poor flocculation. Calcium above 50 ppm supports yeast health, enzyme activity, and protein precipitation during the boil. This is why our systems are designed to allow mineral addition post-RO rather than targeting absolute zero TDS; the brewer controls the final chemistry intentionally rather than accepting whatever the tap delivers.