Lesson 3 - Malt Intake, Handling, and Storage SAQ

***Explain the hand (physical) examination of malted barley. What do these checks tell us about the malt and how it will perform in the brewery?

Response:

• Homogeneity − the evenness of kernel size, shape, and plumpness is examined. The size of the grain is important if using roller mills because smaller grains can pass through without being comminuted. Also, smaller grains have lower extract potential and often have higher protein levels.

• Varietal purity − while it cannot confirm malt variety definitively, there are characteristics of grain physiology that are specific to a particular variety. The malt variety is important because if it is not an approved variety, it is not likely to process effectively in the brewhouse. It is also important if the variety is declared in marketing information. A brewery claiming to make beer from a specific ingredient while using others instead could be subject to legal action from customers or regulators.

• Damage – grains are checked for breakage, dust, husk damage, and discolouration. Like small corns, damaged grains are less likely to be crushed effectively and will lead to extract loss.

• Modification – a device called a farinator can be used to cut the grains laterally or they can be cut or sanded longitudinally to allow a visual evaluation of the endosperm. The degree of modification affects how the grain will process in the brewhouse. Only six-roll mills and hammer mills will crush under-modified grain and it is not suitable for isothermal mashing. High levels of undegraded cell wall materials will lead to a reduction in extract recovery and problems with wort separation. Over-modified grain will cause problems at milling, as it is highly friable. It can also provide lower extracts and cause high colours and poor foam stability in the finished beer.

• Infestation – any evidence of infestation such as chew/bore marks in husk, mouldy grains, animal droppings or insect parts in the sample mean the malt will be unsuitable for brewing.

• Moisture – if the grain is obviously damp it will deteriorate rapidly in storage and the enzyme potential will be reduced. Damp grain will also not mill correctly, so extract will be very low.

• Foreign material – this will cause problems and potentially catastrophic damage during milling unless it is removed before use. If it does make it through into the process, the foreign material could cause taints and will also provide no extract.  

• Colour – if the colour of the malt is incorrect or uneven, the colour of the beer produced is also likely to be out of specification.