The small explosion inside the building on North Pennsylvania Avenue also sent one person to the hospital.
Emergency Management Director Stephen Bekanich said workers evacuated the brewery, and one person was taken to the hospital after being exposed to the chemicals.
He said the local community was never in danger.
This is the second ammonia leak in two months at the facility, but Bekanich said the events are not related.
The cause of the leak is under investigation, and it's unclear when the business will re-open.
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