Homebrewing was an integral part of our early development and we are excited to celebrate National Homebrew Day on May 7th!

I started homebrewing back in Wilmington with an old 5 gallon pot and igloo cooler. I cobbled together a gravity system with old chairs and end tables in the driveway for those early brews.  I always tell people that I had “Dogfish Head Syndrome” when it came to recipe design. Whole fruit, spices, and other adjuncts were all on the table….and I had no business adding these things! A particularly gnarly batch of Winter Warmer comes to mind…way too much ginger!

Then I picked up a copy of “Brewing Classic Styles” by John Palmer and “Designing Great Beer” by Ray Daniels. These two books marked a sea change in my approach to brewing. Out with the spices and in with the classic, fresh ingredients! Zeroing in on ingredients and process improved the quality of my beer in just a few short months!

The hobby gathered steam as I began diving into podcasts like Brewing with Style from The Brewing Network. The show, hosted by Jamil Zainasheff, takes a deep dive into each style, explaining the history, ingredient selection, and important process tweaks necessary to reproduce more technical styles.

All of the accumulated knowledge and experience came in handy as Brian and I began to explore the world of malting. As Brian often points out, I was hesitant to malt a 6-row variety as it was not the preferred barley in a vast majority of the styles I had explored. However, I did understand flavor contributions and brew house performance….which quickly changed my mind about Thoroughbred. Just a quick mill adjustment and we were getting great flavor and decent extract from our early test batches. We entered one of these in a homebrew contest and were chosen by Mike Karnowski from Green Man (now Zebulon Artisan Ales) as his favorite!

This is just one of the “happy accidents” that got us where we are today. Happy National Homebrew Day and we look forward to sharing more memories as we explore our 10 year history over the next few months!

Here’s the original recipe….

We work hard to produce consistent, quality malt. As part of this process, we send every batch to a third party lab which provides us with a full Certificate of Analysis (CoA). A recent review of a discrepancy in color, prompted an interesting discussion between the two laboratories that we use, Montana State University Malt Quality Laboratory and Hartwick College Center for Craft Food and Beverage.  Cheers to Hannah (MSU) and Aaron (Hartwick) for the their thoughts and edits on this post!

To provide some background, each component of the CoA has a standardized methodology associated with it that was developed and approved by the American Society of Brewing Chemists (ASBC). All laboratory testing follows these guidelines. However, different equipment, staff, and testing conditions can lead to variations in results.

How do our intrepid scientists address this potential problem you ask?

They employ rigorous internal and external quality practices to ensure both precision and accuracy in test results. . These include 1) participation in the ASBC Lab Proficiency Program – regular testing of blind samples with comparison of results across 19 labs from the US and Canada and. 2) daily in house control charting  to catch any inconsistencies on the spot. 

It is important to note that this level of effort helps define and control the acceptable levels of variability within each lab, but does not eliminate it!

Let’s look at a few examples that illustrate this point…..

1. Color – As we’ve grown, consistency in this department has become paramount. Brewers (and their customers!) have expectations regarding the color of their finished products. If we miss in this department, problems can arise quickly. Note that a normal difference  between labs can be up to 0.6 SRM. Given this information, we typically allow for a swing of 0.5 SRM in our base malts.

• Extract – Another “hot button” topic for larger breweries. Lower extract/efficiencies equals lost revenue at a measurable scale. A variability of 1.4% could mean the difference between winning a contract or making a price concession. We have recently updated our specifications on the website to reflect a “minimum” rather than an absolute percentage to reflect this reality.

Understanding and accepting this variability comes with the territory of working with an agricultural product. Definitely something for both maltster and brewer to keep in mind when discussing final results!

If you are interested in learning more about this topic, The North American Craft Maltsters Guild is hosting a Malt Analysis webinar on March 25th!

https://craftmalting.com/events/member-webinar-meaningful-malt-analysis/ 

The typical variation for the most common malt tests are listed below: 

The “repeatability” (r95) is the maximum expected difference between two test results on the same sample from the same lab.  

The “reproducibility” (R95) is the maximum expected difference between two test results on the same sample from different labs.

Inside the Matrix….Beta Glucan and Arabinoxylan

𝛃-glucan is a glucose polymer that is found in the cell walls of the endosperm. 𝛃-glucan along with another non-starch carbohydrate called arabinoxylan (or pentosan) comprise more than 70% of the molecular weight of these cells.

High 𝛃-glucan levels in finished malt can lead to a laundry list of headaches for brewers, so it lands squarely on the shoulders of the maltster to manage the degradation of these polymers. In truth, we are simply setting the stage for a variety of enzymes to go to work breaking down these matrices. 

Steeping the grain to approximately 45% moisture with adequate fresh air delivery is the key first step. This hydration activates the aleurone layer to synthesize hydrolytic enzymes such as 𝛂-amylase, 𝛃-glucanase, and pentosanases which are released into the endosperm. Cell wall degradation quickly follows and 𝛃-glucan is solubilized. This process continues over the four day germination period. Maltsters focus on delivering large amounts of humidified air and maintaining cool temperatures in the grain bed to support this enzymatic digestion. The final kilning step stabilizes the enzyme package, making them available for use in the mash.

The success (or failure) of the maltster’s efforts in this department are reflected in the 𝛃-glucan levels concentration reported in the Certificate of Analysis. These levels are reported in milligrams per liter. This methodology primarily captures the longer chain polymers that represent the high molecular weight portion that contributes to filtration issues and stuck mashes in the brew house.

In the United States, most brewers look for this concentration to be below 100 mg/L. However, European brewers accept much higher levels, sometimes exceeding 250 mg/L. This discrepancy could be a result of the need for rapid filtration among the larger breweries in the United States. 

Arabinoxylan levels are not reported in the CoA, but are present in all cereal grains but found in highest concentrations in rye. These carbohydrates play a significant role in determining viscosity and filterability rates for brewers. Published research has documented levels exceeding 300 mg/L from samples that registered ~50 mg/L 𝛃-glucan. In other words, that stuck mash could be a result high molecular weight arabinoxylans and not 𝛃-glucan.

So what can we do as maltsters to drive degradation of arabinoxylan? The answer is not much. Early enzymatic activity within the endosperm is focused on stripping sections of pentosan away which allows access to the 𝛃-glucans beneath. Current research has documented the presence of a xylanase inhibitor that develops midway through the germination stage which reduces further degradation. Some have suggested that the introduction of exogenous enzymes would aid in this function.

Just something to consider the next time you are dealing with a slow runoff or stuck mash!

-Brent

Planning for a successful batch of malt or brew day starts with a Certificate of Analysis (CoA for short) which provides a tremendous amount of information about the malt you will be working with. In the early days, these laboratory analyses were cost prohibitive for us….costing upwards of $300 a sample! Thanks to the good people at Hartwick College and Montana State University we are able to test every batch we produce.

What does this mean for our customers? More consistency and transparency. Maltsters use these data to guide our operations on a daily basis. In this first installment, I’ll cover extract from the maltsters and the brewers perspective.

Extract levels, commonly presented as Fine Grind Dry Basis, or FGDB, attest to amount of fermentable sugar that is available. Modern expectations for extract should exceed 79% for 6-row barley and 80% for 2-row barley. If we have a poor crop year with low test weights (<46 lb./bushel), these can be challenging to achieve. Good harvests make our jobs a little easier!

If we see extract levels declining for a good lot of barley, we can make several changes to our production plan. For example, we might choose to extend germination to allow more time for the cell walls to be broken down into additional starches and simple sugars. The trick is balance. If we go too far, soluble protein levels may increase beyond acceptable levels. This could translate to a thin, watery beer.

Brewers will use this number to determine how much malt is required to achieve a target starting gravity. Some quick math can help translate FGDB into extract potential…

Extract potential (S.G.) = 1 + (FGDB/100)*0.04621

The 0.4621 multiplier in the formula is the extract potential of sucrose (1.04621), against which all extract is measured. For example, Batch 2073 of Southern Select with a FGDB of 81.4% results in a calculated extract potential of  1.03761. Roughly 37.6 points per gallon.

Having this data available can help avoid unexpectedly high or low starting gravities that might negatively impact customer expectations, judging performance, or cost considerations.

Hopefully, this series will provide some interesting insight into how maltsters use CoAs to make process changes throughout the year in an effort to delivery consistent, flavorful products!

• Brent