This week we’re going to talk about protein content in base malts.  This subject has always seemed extremely scientific and complicated to me, and I wasn’t sure exactly what effect it had on my efficiency, color, consistency, or overall finished beer.  These are all important factors, for craft brewers and homebrewers, when concocting a beer recipe. To make the best beer, you have to know what you’re working with, and how to manipulate it so you can make your best finished product.

To understand protein content, first we need to know what it is and what it does. The proteins formed in barley start in the field, and are affected primarily by fertilizer and weather conditions.  Hot, dry growing seasons will create elevated levels of protein in barley, while cool and damp growing seasons will create more moderate levels.  Fertilizer is important because under-fertilized fields will yield lower proteins, which at their basic level are carbohydrates with added nitrogen atoms.  Nitrogen in fertilizer is what gives a plant energy to grow, so it makes sense that it will have an affect on the overall protein levels in the harvest.

Proteins in barley are divided into a few different categories based on their solubility, meaning what they dissolve in.  These are albumins, soluble in water, globulins, soluble in salt water, prolamins, soluble in alcohol, and glutelins, which are not soluble in any of these.  These are organized into two groups, storage and non storage. The non-storage proteins are the source of the most important enzymes in brewing, like amylase, which we use to cut the larger starch molecules into fermentable sugar in the mash, as well as other compounds responsible for forming foam.

These different protein compounds play a huge role in malting, as they are the storage units that allow the barley to begin growth, the driving force behind the malting process.  

The Malting Process

When we make malt, we utilize the natural propensity a plant has to grow.  It germinates, utilizing this plethora of proteins to create the enzymes and compounds the seed needs to break down stored carbohydrates into sugar that it can ‘eat’ to convert into energy that can then be used for growth into a new plant.  The difference is that instead of letting it grow, we stop it right before it converts all of those carbohydrates (long chain sugars) into simple sugars, so that we can utilize all of those enzymes and starches that are ready to go at our leisure to make delicious beer.  

You can see how important all of these proteins are, then, and that there have to be at least some proteins in order to make sure the process works when and how we want it to.  Zero protein malt would be useless to us, and in fact wouldn’t even be malt!

Protein Components in Beer

Protein is broken down in malt to a fairly simple and understandable ratio:  Total Soluble Protein to Total Proteins, or S/T. As we turn barley into malted barley, proteins are broken down into smaller parts.  The smaller parts are capable of going into solution, and you can measure how well modified the malt is by this ratio, which is also known as the Kolbach Index.  Each malt and malt variety is different, so you can use this ratio to determine what the best base malt is for your chosen beer. Generally speaking, the higher the S/T, the better modified the malt is.  You can always find this information on your malt analysis, which is always available from us and our malt suppliers.

Another important component is Free Amino Nitrogen, or FAN.  Yeast require a certain amount of FAN to eat for replication and fermentation in your beer.  FAN is really a measurement of amino acids available from the malt, but too much can affect your overall beer quality.  

By the time your malt hits your mash tun, many of these issues have already been dealt with, by people who have studied and professionally created malt for a very long time.  Protein levels in your base malt have been analyzed, different malt varieties have been tested and properly malted to create more consistent protein levels, and proper levels of Free Amino Nitrogen (FAN) have been confirmed for the base malt that you are using.  The question is, then, why do I care?

It helps to understand what you’re working with, and to make an informed decision when creating your favorite pale ale recipe.  If you use malted wheat, renowned for it’s naturally high protein levels, you’ll know that when the beer doesn’t clear up, it’s because of elevated protein.

What if you get awesome local barley for a killer price, but can’t seem to make a consistent batch?  If you’ve ruled out brewing process, as you’re consistent and diligent during brew day, then you’ll know that the malt can be the culprit.  If your local 2 row producer is mixing higher and lower protein batches to ‘even out’ the levels, it can make for very inconsistent brewing results.  Higher levels of protein can even mean less fermentable extract per pound of malted barley, which means you’ll have to use more grain and always wonder why you can’t seem to make a decent high gravity beer with a reasonable grain bill.

Higher protein levels can even temp non-saccharomyces microorganisms as a food source, as they can access the nutrients that protein provides, making your beer more likely to sour or spoil.  High proteins will even have an effect on color and extract potential, making your finished beer darker and lighter in gravity than you planned. 

Protein levels are a big key in brewing consistency.  As a rule of thumb, ensure that your base malts have protein levels between 9.5% and 12.5%.  Below 9.5%, you will experience poor efficiency in the mash tun because you won’t have enough enzyme to convert your carbohydrates  Think of doing a Munich malt S.M.A.S.H; it has just enough enzyme to barely convert itself, but efficiency sucks. If it’s above 12.5%, it will limit the carbohydrates that you actually have access to, meaning poor efficiency, because the grain has trouble taking up water and the enzyme can’t get to the starch.  On top of that, you work towards creating a very hazy beer unless you use extra enzyme like Clarity Ferm.

Certificates of Analysis

Modern maltsters always give Certificate of Analysis (COA) access to suppliers, distributors and end users.  This means that you can walk into our store and simply ask for malt lot analysis information, and we have it and are happy to give it to you, or show you how to find it.  There has been so much great science done on malt that there is rarely a ‘grey area’ of quality. You always know that you are getting a quality brewing grain and quality malt extract because in the brewing industry, home brewers and craft brewers demand it.  But it helps to know what you’re looking at, and to know what you can and should be using for different beers and beer styles.

Thank you for reading!  Please post comments and questions below to continue the conversation!  

References:

• Malt - A Practical Guide from Field to Brewhouse - John Mallett
• Understanding Malting Barley - Aaron Macleod
• Protein Changes During malting and Brewing with Focus on Haze and Foam Formation:  A Review - Elisabeth Wiesen, Martina Gastl, Thomas Becker -  European Food Research and Technology
• Crafting Quality:  It Starts With Malt - All About Beer Magazine December 18, 2015
• Understanding Malt Spec Sheets - Brew Your Own Magazine, BYO.com