As harvest progresses, growers can look forward to relieving pressure on their cash-flow by selling some of their grain - but a lot of sampling, testing and recording has to be done before any lorries are loaded. Failure to meet the specifications of a contract can result in the buyer rejecting the load and the farmer being offered a lower price, or having to find a new buyer for that rejected load. That can involve the expense of additional haulage to the new destination.

To avoid refusals, unexpected deductions and disputes, you must know the quality standards of your product. Knowing what you have can allow you to ensure that you meet specifications - so good sampling and analysis are vital.

Different buyers have different requirements depending on what the grain is to be used for. Most will insist that the grain is free of contamination by weed seeds and insects such as storage beetles and mites.

The moisture content of the grain is also very important, and should be below 14.5 per cent to allow for safe, long-term storage without fear of mites breeding, or moulds developing.

Mycotoxins are toxins that infect crops and/or grow on grain. In cereals, contamination by mycotoxins can result from either field-borne infection or from fungi that develop in stored crops. Legal limits exist for the three principal mycotoxins that may occur in cereals and cereal products intended for human consumption. Guidelines also exist for cereals intended for animal feed.

It is the responsibility of all food business operators (including farmers, merchants and processors) not to place on the market any cereal or cereal products that exceed the legal limits. This means that all sellers must be able to demonstrate due diligence in determining the levels of mycotoxins that are present.

Germination is another important attribute of grain, particularly if it is to be used as seed or for malting. Malting depends on high and predictable germination, and malting barley is purchased on the basis of a germinative capacity test, which takes place at delivery. Damage during handling such as skinning or broken grains can impair germination, so many maltsters allow a maximum of 2 per cent broken grains.

The specific weight, or bushel weight as we used to call it, is also very important, particularly for wheat, and is expressed nowadays as kg per hectolitre (kg/hl).

For both wheat and barley one of the important constituents of the grain is its nitrogen or protein content. Depending on the intended end use of the grain, a wide range of nitrogen/protein contents are utilised provided other required attributes are present.

For example, bread-making wheat requires a minimum protein content of 13g/100g, whereas wheat for making biscuits requires protein levels to be in the region of 10.5 to 11.5g/100g.

Barley utilised for distilling is purchased at grain nitrogen levels of less than 1.5p/100g, whereas barley intended for grain distilling is likely to be in excess of 1.85g/100g. The majority of the barley purchased for brewing is likely to have a grain nitrogen content in the range of 1.55 to 1.85g/100g.

For the milling wheat market, the Hagberg Falling Number (HFN) value of grain samples is very important. The HFN test measures the number of seconds a plunger takes to fall through a mixture of wheat and flour in water. The plunger falls slowly if the mixture is thick with starch. It falls more rapidly if some starch has been converted to sugar through the action of the enzyme alpha-amylase.

Bread made from flour using grain with too low an HFN value is sticky and clogs slicing machines, so millers reject it. HFN values below 250 are usually not accepted for bread-making. Securing the bread-making premium in wheat can be the difference between a good profit and a substantial loss.

Clearly selling grain is not straightforward. Now the Scottish cereals and oilseeds industry is being urged to consider the possibility of an electronic passport scheme (eGrain Passport), following an 18-month pilot project funded by AHDB Cereals & Oilseeds. The industry has until the middle of September to feed back on the findings, which are available on the AHDB Cereals and Oilseeds website.

The eGrain Pasport would be a world-leading system that would give farmers a quick flow of information both up and down the supply chain, which they don't have at the moment, while customers would be able to see all assurance statuses in a robust format.