Reasons for Rejections

The malting barley variety is critical to the character of the final malt and varietal purity is of great concern to the maltster. Not only do single variety bulks of barley malt uniformly, most brewing and distilling customers select malt by specific variety and maltsters are bound contractually to deliver accordingly.

Splits usually form in the ventral furrow, and as well as impairing the ability of the grain to germinate also allow mould growth to develop.

Maltsters require mature, plump, uniform barley that will germinate vigorously and and uniformly. They do not want skinned, cracked or damaged grains. Skinning and breaking occurs when careless or improper harvesting methods are used. Malting barley that has been harvested and threshed properly should contain few skinned or damaged grains.

Maltsters require mature, plump, uniform barley that will germinate vigorously and and uniformly. They do not want skinned, cracked or damaged grains. Skinning and breaking occurs when careless or improper harvesting methods are used. Malting barley that has been harvested and threshed properly should contain few skinned or damaged grains.

Good malting requires plump, even sized corns, which must be covered by an even husk without ‘gape’ or splitting. Water uptake into the grain must be at an even rate and amount; to ensure that germination all takes place at the same time and with equal vigour. Variation in husk thickness, or incomplete husk coverage will affect water uptake. Small or under-sized grains will not perform as well as ideal corns, so standards are set, based upon the percentage of grains retained over a screen.

The standard of most countries, except England and Wales, is 90% retained over a 2.5mm screen. Scottish growers trade malting barley on the 2.5mm standard, however, the standard is different for barley purchased in England, where maltsters normally accept 94% retained over a 2.25mm screen. UK brewers are attuned to this practice, and the resultant malt.

Incomplete or slow drying can lead to mouldy grain and mycotoxin production

Maltsters will not accept barley containing stones, glass, lead shot, or any other form of extraneous matter

Barley has to grow evenly during the malting process to ensure high quality malt. Unripe or damaged corns cause problems; they do not producing any usable extract (or spirit yield for distilling), and they can impair the quality of the finished malt.

Fusarium moulds are widespread on growing crops and normally do little damage to the plant. However, under some conditions they can produce a number of toxins, including deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEA).

Fusarium toxins in malt can be prevented by choosing good quality barley, by efficient drying and good storage conditions (for both malt and barley) and by attention to hygiene in the malting plant.

Ergot bodies are the sclerotia (food storage bodies) of the fungus Claviceps purpurea. They are rich in alkaloids – poisons which may cause hallucinations, convulsions, or even death in sufficient quantity.

The ergot bodies are dark purple to black, about the same diameter as barley corns, and up to two inches long.

Although not directly for control of ergot, good agricultural practices of weed control, aphid control, and fungal control programmes will reduce the risk of ergot infection of crops.