Terms used in this subpart are defined in the Clean Air Act, in 40 CFR 63.2, in the General Provisions of this part (§§ 63.1 through 63.15), and in this section as follows:

Batch means a single fermentation cycle in a single fermentation vessel (fermenter).

Batch monitoring period means the period that begins at the later of either the start of aeration or the addition of yeast to the fermenter; the period ends at the earlier of either the end of aeration or the point at which the yeast has begun being emptied from the fermenter.

BAVOC means the average VOC concentration in the fermenter exhaust over the duration of a batch (“batch-average VOC concentration”).

Brew means the mixture of yeast and additives in the fermenter.

Brew ethanol means the ethanol in fermenter liquid.

Brew ethanol monitor means the monitoring system that you use to measure brew ethanol to demonstrate compliance with this subpart. The monitoring system includes a resistance element used as an ethanol sensor, with the measured resistance proportional to the concentration of ethanol in the brew.

Brew-to-exhaust correlation means the correlation between the concentration of ethanol in the brew and the concentration of VOC in the fermenter exhaust. This correlation is specific to each fed-batch fermentation stage and is established while manufacturing the product that comprises the largest percentage (by mass) of average annual production.

Emission limitation means any emission limit or operating limit.

Fed-batch means the yeast is fed carbohydrates and additives during fermentation in the vessel.

Monitoring system malfunction means any sudden, infrequent, and not reasonably preventable failure of the monitoring system to provide valid data. Monitoring system failures that are caused in part by poor maintenance or careless operation are not malfunctions. You are required to complete monitoring system repairs in response to monitoring system malfunctions and to return the monitoring system to operation as expeditiously as practicable.

1-hour period means any successive period commencing on the minute at which the batch monitoring period begins and continuing for 60 minutes, except for the last period, which may be less than 60 minutes.

Product means the yeast resulting from the final stage in a production run. Products are distinguished by yeast species, strain, and variety.

Responsible official means responsible official as defined in 40 CFR 70.2.

Set-batch means the yeast is fed carbohydrates and additives only at the start of the batch.

Specialty yeast includes, but is not limited to, yeast produced for use in wine, champagne, whiskey, and beer.

Within-concentration batch means a batch for which BAVOC is not higher than the maximum concentration that is allowed as part of the applicable emission limitation.