Why is moisture measured in grains?

Grain needs to be closely monitored for a number of factors and qualities after harvest, and one of the most critical of these is moisture. Moisture is easily overlooked, especially in a humid climate like that which we’re used to in the UK, but it has serious implications for crops.

Here we look at how moisture can affect grain, why it needs to be monitored and balanced, and the consequences of ignoring the moisture content of your grain harvest.

Why moisture content in grains is important

Moisture content is not the problem with a grain harvest in and of itself; the issue with moisture levels is what can come about because of too much or too little water content. Being organic material, grain is subject to all kinds of threats as a result of inadequate moisture levels.

Additionally, there are multiple points in the production cycle in which moisture can present itself as a problem and multiple opportunities for moisture levels to be unbalanced. For instance, favourable weather does not mean that you don’t need to worry about moisture levels for your crop henceforth. Humid storage can still present an issue later into production.

The consequences of improperly monitoring moisture levels can be costly in both time and money. The upshots of inadequate moisture monitoring can be a wasted harvest and nothing to sell, damaging profits and reputation with your buyers.

Furthermore, there is always the risk of ill health to consumers as a result of undetected microbial growth and mould from moisture, which has far more drastic consequences both morally and financially.

Moisture content is an important enough quality in and of itself, but its ability to also affect the weight of grain and its temperature through knock-on effects makes it an essential point of measurement.

What happens if there’s too much moisture?

Moisture is one of the key growth factors for bacteria and fungi, which can quickly destroy a grain harvest and render it unusable. This is because the right combination of moisture, nutrients, and warmth provides the kind of environment where mould thrives — three things which can be abundant in a grain store.

Mycotoxins in particular are a big threat to be wary of, as these are produced by various fungi and can poison humans who ingest them. Mould can lead to decay and an increase in heat, creating a kind of chain reaction that begins with high moisture content.

Mould also presents a respiratory problem for the farmers handling it, which cannot be overlooked.

When grains absorb moisture, the process of germination begins and sprouting occurs. Whilst this doesn’t necessarily spoil the nutritional quality of grains, it may mean the product is not what was agreed and buyers could find it unsightly.

As well as encouraging mould and bacteria, insects and mites may also thrive in moisture and a food source such as grain. This is because mites absorb moisture through osmosis, so they thrive in environments of high ambient humidity.

What happens if there is too little moisture?

Grain above a certain moisture level is often dried as part of the production cycle, and while a high moisture content is something to avoid, overdried grain is equally something to be avoided.

Overdried grain can crack and split, becoming brittle and easily damaged. This damage can make it more susceptible to pests and provide an easier route for moulds and other problems to take root.

Too much drying also causes shrinkage, reducing the overall weight of the grain and therefore reducing the profits of its sale. Since grain is sold by weight, reducing the overall bulk of the crop on top of having to throw away some of it due to damage means that overdrying can severely cut into profits.

Too little moisture that has occurred naturally as opposed to drying may indicate some underlying problem with the crop itself, and will likely need further investigation if it has occurred on a widespread scale.

Too little moisture also means that assumptions can be fatal to the crop. If a rough estimate of moisture is always assumed and drying is carried out according to that assumed figure, then drier grains with lower moisture levels will suffer from that

How to measure moisture

First thing’s first: to properly understand the moisture levels in grain and judge what needs to be done, accurate equipment needs to be used.

Measuring moisture using specialist analysis equipment is the best way to determine the state of your grain. Perten’s AM5200 Grain Moisture Analyser can test a grain sample for moisture, weight, and temperature to give you a comprehensive view of where your crop currently is and what needs to be done.

The benefit of these instruments is their reliability and repeatability, not to mention how fast they deliver their results. With a quick on-site test of moisture, both buyer and producer can agree on moisture levels and weight and come to a more informed decision.

Moisture readouts are delivered as percentages, making them easy to understand and to measure against an acceptable threshold according to the type of grain.

The AM5200 uses the Unified Grain Moisture Algorithm (UGMA), an open standard for measuring grain moisture that is free for any manufacturer to use. The algorithm uses dielectric constant (or relative permittivity), which is a measure of how much electrical energy a substance can store.

Fast measurement means moisture can be ascertained more frequently, allowing informed actions to be taken and returns to be maximised.

Measuring moisture in grain with Calibre Control

We supply expert equipment and advice on measuring moisture in grain, helping you avoid disastrous mistakes and giving you the means to get the most out of your crops. To learn more about our services, contact us today.