Acute indoor concentrations of benzene and ethanol were evaluated in the California Polytechnic State University San Luis Obispo’s pilot winery workroom. Air samples were collected during four different wine-making activities: fermentation, fermentation with Brix content testing, post-alcoholic fermentation pressing, and storage/finishing. Average workroom benzene concentrations ranged from 0.05 to 0.12 mg/m3. Ethanol concentrations in the winery workroom varied with the activity, ranging from 0.9 to 12 mg/m3. Pressing and fermentation with Brix content testing both led to higher indoor ethanol concentrations than fermentation without Brix content testing and storage/finishing. Tracer gas decay air exchange tests were conducted to determine the air exchange rate of the winery workroom. A single-space mass-balance model was used to estimate the air exchange rate for the entire workroom. The calculated air exchange rates were correlated with wind speeds and wind direction to create a linear model estimating air exchange rates based on wind speed. These air exchange rates and the indoor concentrations of ethanol were used with the single-space mass-balance model to calculate an ethanol emission rate for each activity. Total estimated ethanol emissions for the four activities were 3.1 lbs. ethanol per 1000 gallons of wine produced.