Since 1870 we’ve lived and breathed malting. With this passion and expertise, and by combining traditional and modern techniques, we create an impressive range of malted and non-malted products, including several unique and exclusive barley malts.
There is nothing more we love than talking to brewers and distillers so if you have any questions, or would like to arrange a call with a member of our team, please feel free to get in touch – we would love to hear from you!
The Certificate of Analysis
Scroll Down
The malt Certificate of Analysis (or CoA) can be a daunting document, and many craft beer brewers just look to it for extracts to calculate brewhouse efficiency and see how much alcohol they can potentially get out of it. However, with careful study, you can unlock so much more information, which can provide insight into perfecting your milling, mash, fermentation, and filtration to get the most out of your Crisp Malt.
Some of the parameters affect the milling of malt, so it’s worth looking at even before you crush it. Other parameters enable you to tweak your recipe or mash profile to perfect the amount of extract you get out of it and adjust it so that you avoid potential problems further down the line. It might give you a heads-up as to how the beer might ferment, how yeast might perform or how good it will be to filter. Many of these parameters can be adjusted for by the brewers themselves to provide consistent products every time. We obviously do our very best to maintain tight spec specifications and a very consistent product to take a lot of the headache away from constant recipe changes, but we are working with a natural raw material which has variations between different fields, from year to year and between varieties. We generally do our upmost to warn you if any of these parameters are out of specification and give you advice on what to do if they are. With careful adjustment, as long as they are not too far away from specification, a lot of these should not cause you any major issues.
Before we breakdown individual parameters and what it means for brewing beer, some housekeeping is required – different parts of the world measure the same thing differently! Generally, in the UK, we look at IOB – Institute of Brewing. These tests are performed to replicate a single infusion mash. Any mini mashes are mashed in at 65⁰C for an hour, similar to a regular British mash tun. America uses ASBC (American Society of Brewing Chemistry) and Europe (and most of the rest of the world) tends to use EBC – European Brewing Convention. Both ASBC and EBC methods involve the lab mash replicating a step mashing technique, mash in at 45⁰C for 30 minutes before being raised to 70⁰C for an hour. This replicates a mash conversion vessel step mashing procedure. It is generally advisable to pick the testing that more closely represents your brewing regime to get a closer understanding of how the malt is likely to perform in your brewery.
So, what is it that we should look out for?
This tends to be the first thing the brewers look for because this is where you make your money. If extracts are low, you’re not going to get enough alcohol to produce the product that you need. If extracts are reasonable, you may be able to take out extra bags of malt that might not be necessary, therefore saving yourself some money. It’s a good idea to compare these like for like between batches and from year to year and monitor if there are any dramatic changes one way or the other. For distillers, extract is everything, because alcohol is everything. Distillers tend to choose low nitrogen varieties of barley as with lower percentage of nitrogen content, it makes way for higher starch content so more sugars for more alcohol. Brewers have to have a reasonable level of nitrogen vs starch content as nitrogen (proteins and amino acids) are needed for head retention and yeast health.
If you have a base malt with low extract, unfortunately, the only way you are going to get the correct gravity is by adding more malt, which can get expensive.
Many brewers use extract from the CoA to plug into their calculators to work out brewhouse efficiency. Don’t be disheartened that it seems impossible to get similar to the CoA extract, extracts in the malting lab are measured using malt milled on a rotary mill at 0.7 mm mill gap. This is a much finer mill than majority of brewers use so will result in higher lab extracts. The exception to this rule is if you have a hammer mill which will produce much higher percentage of flour and a much finer grist, therefore opening up much more of the sugars within the malt enabling them to leach out into your wort, increasing your extract. Also, always look at ‘as is’ values rather than ‘dry’ as these will take moisture of the malt into account.
If you receive your malt crushed, the consistency of this crush has a major impact on the extract that you are able to obtain. A finer grist will expose more sugars, enabling you to get more extract out of your malt. However, it can cause serious wort separation issues and stuck mashes as it can easily block mash plates. If the grind is too coarse or there are any uncrushed grains (which can be due to variation in grain size and not enough screening within the maltings allowing small corns to go through the mill uncrushed) can mean that you are paying for unusable grain. If the grain is not broken open, you cannot extract sugars from it. You are generally looking for an average crush with good amount of husk for wort filtration (recommended 40 to 30% husks), a reasonable amount of flour (max 10%) and good amount of grits (50 to 60%). If you have finer slats in your mash bed you can push a finer grist (with caution) to optimise getting the most amount of sugar from your grain without stuck mashes.
Often measured as wort colour. Consistency is highly important as inconsistencies can lead to customers questioning the strength of the beer or even if they have the correct product. It could mean you adding more coloured malts to adjust the colour of your wort or even extra malt extract products to adjust it pre-packaging. This can be difficult to predict and irritating to have to adjust recipes continuously. There is a bit of a payoff between colour and moisture. If the grain is very wet and we need to further reduce the moisture during kilning, the colour will increase, it is a very careful balance between removing enough moisture for good storage and not darkening the malt too much.
If a malt base is too low in colour, you can adjust the colour by adding a small amount of crystal malt. However, if your base is too high in colour, your wort will end up too dark, so it’s best to remove some coloured malt (if there is any).
An easy and cheap way to check your consistency of colour is to take a photo of your beer and use it as a comparison.
This can be a malt storage concern if above spec as previously mentioned, it is often conversely related to colour. Occasionally we might have to be on the high side of moisture to avoid increasing the colour of the malt too much during kilning.
Malt with high moisture content is more susceptible to pest infestation and damage or ingress of mould, which can affect flavour. There is no low spec for moisture, but if your if above maximum specification, then it is best to use it fairly quickly and not to store for extended periods of time. Keeping it in a cool environment with minimal temperature changes are always advisable, and I would recommend assessing the quality and aroma of the malt prior to using it.
Nitrogen content is measured in the barley before we even accept it into the maltings. It is a natural part of barley and percentage content of barley varies from year to year and between varieties.
Nitrogen is broken down during germination in malting by protease enzymes and different parts of this nitrogen content are responsible for foam formation and retention or yeast health.
High levels of total nitrogen within the malt grain can reduce the amount of starch molecules, and therefore can reduce extract. Brewers need some nitrogen (proteins) as they contribute towards foam formation (head retention), without which your beer will look flat as a pancake which can allow customers to believe the CO2 content is too low. Nitrogen content is depending on barley variety and tends to differ from year to year.
This is a measure of how far the total nitrogen has been broken down during malting into soluble nitrogen components. The soluble nitrogen ratio can be a good indication of the level of modification of the malt (breakdown of cell walls). If it is too low, the endosperm in the grain may not have been fully broken down so extract may drop and FAN levels may be too low (see FAN). Over modified malt or high SNR can lead to high FAN levels, which can over produce yeast leading to fermentations over shooting target and problems with filtration or yeast settling issues and potential haze problems at later stages.
Too high SNR can increase chances of haze and filtration problems.
Stands for free amino nitrogen. These are some of the building blocks for new yeast cells, so are important in the early stages of fermentation, where yeast goes through a rapid replication stage. Low levels of FAN means yeast is unable to build new cells and which can result in sluggish or stuck fermentations. High levels of FAN can encourage too much yeast growth, making fermentations over attenuate and yeast difficult to remove later, either in cask or blocking filters. Certain yeast strains are more fussy about FAN levels than others, so it is helpful to know what your yeast likes. Low levels can stress yeast which can affect negatively affect flavour of final product.
This is the measure of enzyme activity potential within the malt. Barley comes with precursors for enzymes that start to break down the cell walls within the endosperm during germination to release the starch molecules, and start to breakdown the long starch chains into shorter chain sugars, accessible for the yeast.
Beta and alpha amylase starts to break down the starch into smaller chain during germination but a high percentage of them are preserved in the malt so they can further reduce the starch during mashing.
Higher kilned malts such as ale malt, will potentially have a lower DP value than an extra pale or a lager malt, because the increase in kiln temperature and duration denatures more of the enzymes. For an ale malt, a DP value of 45 is sufficient and 60 DP lager malt. If the DP value is higher, you may want to increase your mash temperature to avoid creating too much fermentable wort and leaving your beer thin. If DP values are low, you have to be cautious if adding a lot of adjuncts may not contain enzymes, such as rice and maize and highly kilned malts, where the enzymes have been denatured, as they dilute the total amount of enzymes within the malt.
This is a measure of how crushable the malt it is and it is affected by it’s level of modification. A lower modified malt has more cell structure remaining so is still quite hard, like the original barley. Malt needs to be friable to be milled sufficiently to access the starchy endosperm, otherwise you lose extract.
Beta glucans are polysaccharides that make up a large percentage of the cell wall that holds the starchy endosperm together. The germination process of malting releases beta glucanase enzymes that start to break down the cell walls into smaller polysaccharides, freeing up the starch molecules within them.
Beta glucan levels are not routinely displayed on CoA because they can vary somewhat and are dependent level of modification. Beta glucans can come as long chains and short chains. You could have many short chain beta glucans and never have an issue or you could have very few long chain beta glucans which can create a very viscous wort. High levels of glucans generally over 200 can cause wort run-off problems and can be problematic in filtration. The better parameter to look at in this situation is wort viscosity which is closely tied to beta glucan levels, but gives a more realistic view of how problematic those glucans are going to be (i.e. run-off or filtration issues). If you encounter high wort viscosity, best option is to add beta glucanase enzyme to the mash which helps chop up some of the long chain beta glucans, which tend to cause filtration issues. Beta glucanase is active within malt naturally, but tends to work at lower temperatures (45-50⁰C), so if you were lucky enough to have a mash conversion vessel, you can extend the protein stand to allow the enzymes more time to further breakdown the long chains.
We hope that this blog will be super helpful to you and your brewing plans, and will hopefully become a tool you can use regularly! If you feel that you still need some Crisp Malt technical support, please don’t hesitate to get in touch. We have a team of experts who have brewing backgrounds, who are doctors, and who work in our in-house lab, all of which can help you in your brewing journey. To get in touch with the Tech Support Team, head to our contact page.
Back to top
