By Aaron MacLeod, Hartwick College Center for Craft Food and Beverage
To ship, or not to ship, that is the question.
Many craft malthouses use the services of a third-party lab to obtain standard malt analysis to characterize their malt as an important part of their quality management system. This provides valuable feedback on product quality and process control. However, in some circumstances, a decision on whether or not to ship a particular batch must be made before test results are received from the lab. Unintentionally shipping a product which is out-of-spec can result in a disappointed customer and a negative impact on your business and brand.
Fortunately, there are a number of tests that can be performed in the malthouse that can indicate if a batch of product meets your quality specifications.
The final moisture content of the finished malt can be determined using a moisture balance analyzer (the same instrument that is used for measuring moisture content during steeping and germination). When using the analyzer for finished malt it is important to always grind the sample first in a coffee grinder to increase the surface area and lower the measuring temperature to 105°C to prevent the sugars in the malt from burning.
There is a strong correlation between final moisture and both color and Diastatic Power. Lower than normal moisture content in the finished malt can be an indication of changes in the kilning process resulting in potentially higher color, and lower diastatic power (and vice versa).
Friability is a rapid and repeatable measure of the extent of cell wall modification of the malt using an instrument that conducts a standardized crushing test. Think of the Friabilimeter as providing ‘x-ray vision’ into the interior cell wall structure of the kernel. High amounts of PUG (under-modified kernels) or WUG (poor germination) indicate heterogeneous modification or dead kernels. Keep in mind that the friability target will change by variety, protein level, and crop year.
Friability is typically useful only for base malts as it is not appropriate for specialty malts, such as caramel malts, which are glassy and hard by nature. The test can also be less useful for malts made from grains other than barley, such as wheat or rye as they have a distinctly different endosperm texture.
While the Friabilimeter is an expensive instrument (~$7,000 USD) it will last the lifetime of your malthouse and requires very little maintenance. Think about the investment in terms of the value of instant feedback on your malt quality or preventing damage to your brand by shipping a bad batch.
The ASBC Hot Steep Method can be used to provide a fast and reliable visual estimate of the malt color. It is possible to visually detect a difference in color as small as 1 Lovibond using the Hot Steep when comparing two malts side by side. By doing this regularly, you can become familiar with the color of your products, and will be able to recognize when it’s off.
With the additional use of a visual color comparator, you can even assign a color value without the need for a spectrophotometer. A comparator system with color standards can be obtained here.
A brewer would never ship a batch of beer without tasting it first. The same goes for your malt. The ASBC Hot Steep method can be used as part of a formal or informal sensory program in your malthouse. At a minimum, tasting your malt will help you identify if it is close to your target style or if off-flavors are present that might indicate a process issue.
Using the Base & Specialty Malt Flavor Maps (available in the Guild’s online store), it is possible to define a set of standard descriptors for each of your products to help determine if a batch is ‘true to brand’. DraughtLab software is also a useful tool to facilitate your sensory assessments and data.
All the methods described above, and more, are detailed in the Guild’s Quality & Safety Manual (also available in the Guild’s online store). Using these tests in your malthouse as part of your integrated quality management system that also includes raw material testing, in-process measurements, equipment data-logs, and 3rd party final product testing will give you the assurance you need to feel confident that you are shipping a quality product to your customer.