Description
- Final pH: 5.6 ± 0.2 at 25.0°C * Grams per liter may be adj. or formula supplemented to obtain desired performance
- Preparation: Mix 66.2 grams of the medium in 750 mL of purified water until evenly dispersed. Heat with repeated stirring and boil for one minute to dissolve completely. While the medium is hot, add and mix 250 mL of beer without degassing. Distribute and autoclave at 121.0°C for 15 minutes.
- Quality Control Specifications: 1. The powder is homogeneous, free flowing and beige. 2. Visually the prepared medium is light to medium amber and clear to slightly opalescent. 3. Expected cultural response after 24-72 hours at 30.0°C.
- Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light beige color.
- Formula* per Liter: Tomato Juice Broth ......................15.0g Beef Extract................................... 2.0g Maltose........................................15.0g L-Malic Acid ................................. 0.5g Dextrose ......................................10.0g Polysorbate (Tween) 80................. 0.5g Dipeptone .................................... 5.0g L-Cysteine, HCl ............................0.2g Potassium Acetate........................3.0g Agar.................................................15.0g
Use: An agar medium used for the detection and enumeration of beer spoilage microorganisms (lactic acid bacteria). Description: Barney Miller Agar was developed at the Miller Brewing Company to detect the presence of Pediococcus ssp. and Lactobacillus ssp., the 'lactic acid bacteria' responsible for beer spoilage during the stages of brewing which are the most anaerobic (fermentation and maturation). This group of organisms can tolerate and multiply under the inhospitable conditions found in the brewing process as the beer becomes oxygen deprived, the pH drops and the alcohol concentration rises. As these organisms grow, they further lower the pH, create turbidity in the beer and alter the beer's flavor.
