We provide information on:

• How to interpret technical information about diastatic power, FAN, Kolbach Index ratings, friability and the moisture content of your malt
• How to use our malts to achieve the best results
• Mill settings and crush size
• Malt pH levels, and how to adjust pH to suit brewing requirements
• What mash temperatures to use to get the most out of our malts
• How best to use the roasted and coloured malts that we produce

Diastatic Power (DP)

DP measures the strength of the starch-reducing enzymes in base malts using the Windish Kolbach (WK) scale. When grain is malted, enzymes are produced during germination. These enzymes convert the grain’s starches into sugar during mashing.

If there aren’t enough enzymes, then there isn’t sufficient conversion of sugars which means there isn’t enough food for the yeast.

If there is too much enzyme activity, the yeast digests all the sugars meaning that there is no residual sugar. This leads to poor mouth-feel and a thinly brewed beer.

To achieve a well-balanced beer, you need a good mouth-feel and have residual sugars especially if you are using lots of hops.

DP is also very important when brewing with a high proportion of specialty malts or un-malted adjuncts. There needs to be enough DP to convert the starch in both the base and the specialty malt.

FAN (Free Amino Nitrogen)

FAN indicates the amount of free soluble amino groups available in the wort when using base malts. The right FAN is needed to produce a good fermentation, which will help to create a well-balanced beer.

A low FAN measurement indicates there is not enough food for the yeast which will lead to a low fermentation.

A high FAN measurement means too much fermentation will occur. In this case, the finished beer will be too thin with off flavours.

Kolbach Index

The Kolbach Index measures the ratio of soluble nitrogen or protein to the total nitrogen or protein available and is a valuable tool for determining malt modification.

A high Kolbach Index means the protein particles are too small resulting in a thin beer lacking body.

A low Kolbach Index will produce a finished beer with filtering and haze issues.


Friability is a measure of malt’s ability to crumble when crushed. If the malt is too hard, the malt has not modified well and the fermentation process will suffer.

Maximum Moisture

Moisture and malt do not go well together. Base malts too high in moisture will lower the gravity of your beer so you need more malt to brew the same volume of beer.

Brewers should only crush what you will use, and any leftovers should be discarded.

It is important to store malts in airtight containers and be mindful of using the malt before its “best before” date.


Brewers can tell that they have a good crush when the husk is mostly intact or in large pieces and the endosperm has been broken down into a mixture of larger chunks and smaller granules. There should be very little flour in the crush because this could cause lautering problems with some brew systems.

How finer crush you choose will be based on each brewery’s lautering capabilities.

A finer crush will result in higher extract potential but less lautering efficiency, whereas a coarser crush will reduce the extract potential.

Our Gladfield Malts are high-quality, behave consistently, are plump and highly friable. Adjust your milling settings to ensure you get a perfect crush with our malts every time.

Note: Toffee Malt should always be crushed in conjunction with your other malts because of its higher moisture content.

Malt pH

Malt pH can be influenced by the barley variety, how it has been grown and managed on the farm, nitrogen levels, steep water, degrees of modification, the kilning temperature used, kilning moisture and the type of heat applied during kilning. All these factors and more will have an impact on the final pH of malts.

Gladfield Malts typically have a high pH. If we were to lower this pH, we could inadvertently negatively impact other factors such as fermentability, Kolbach Index extracts and the flavour of the finished beer.

You can easily lower the malt pH in the brew house mash by using Sour Grapes Malt. As a guide, 1% of this milled malt will drop mash pH by 0.1. We recommend between 1% to 5% of our Sour Grapes Malt is used to achieve target mash pH. Remember though that lowering the pH can lead to a reduction in flavour or extract, so do go easy.

Mash temperature

We recommend our brewers use a single temperature infusion mash to get the most out of our malts. We use modern barley varieties and control germination through a high-tech computerise process to control protein breakdown.

Our malts have therefore already gone through the enzymatic breakdown and do not require a step or protein rest.

We recommend mashing at 65°C for a highly fermentable light wort and up to 70°C for a full bodied wort.