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Check It Before You Wreck It

While it’s true that people have been making beer for thousands of years without special equipment, these days it has never been easier to brew your own. For those who don’t want to get their hands dirty, there are all-in-one machines available on the market which will brew beer almost as easy as making a pot of coffee in the morning. The more daring of us choose to design a recipe with a specific grain bill, temperature gradient, and over-the-top sugar extraction (lautering) process, which can result in failure if a single step goes wrong. Over the years, I have learned several things along the way to create the beers of my dreams, and I’d like to share some tips with you.

FIRST STEPS

Before heading into the more nerdy aspects of beer brewing, a glossary of basic terms which describe the process should be laid out:

  • Malting: process of germinating and kilning barley to produce usable sugars in the grain
  • Milling: act of grinding the grains to increase surface area and optimize extraction of sugars
  • Mashing: releasing malt sugars by soaking the milled grains in (hot) water, providing wort
  • Wort: the solution of extracted grain sugars
  • Lautering: process of clarifying wort after mashing
  • Sparging: rinsing the used grains to extract the last amount of malt sugars
  • Boiling: clarified wort is boiled, accomplishing sterilization (hops are added in this step)
  • Cooling: wort must be cooled well below body temperature (37 °C) as quickly as possible to avoid infection
  • Pitching: prepared yeast (dry or slurry) is added to the cooled brewed wort, oxygen is introduced
  • Fermenting: the process whereby yeast consumes simple sugars and excretes ethanol and CO2 as major products

THE MATRIX

If you’ve read my other Metrohm Jubilee blog posts, or enjoyed the beverage yourself, you know that water is one of the main ingredients in beer. Most beers are comprised of between 88–97% water. Water is the medium in which the sugars and starches are extracted from grains, and also where these starches are converted into more fermentable sugars by way of enzyme activity (more on this later). The mineral content of the water is also quite an important factor to achieve the correct qualities and flavors for each style of beer. There is a reason that traditionally, stouts are associated with Ireland, pilseners with the Czech Republic, and so on. While other ingredients could be sourced from afar, the water used in brewing was local, and its chemical composition relied heavily on local geology.

The natural hardness and alkalinity from local water sources were ideal for brewing specific styles because of the buffering capacity of the water. Water high in alkalinity will stay in a certain pH range even if more acidic ingredients are added (such as heavily roasted grains, found in stouts). Today, you can add different brewing salts to your water to modify hardness and alkalinity in order to promote the clearest tones in different styles. For more information on alkalinity and hardness in brewing water, you can download an informative application note I created for the brewing industry which is available on the Metrohm website.

Pro tip: Test your water with a kit (available online) or even better, ask a Metrohm IC Applications Specialist.

pH

The pH has many effects on beer, from flavor stability and head retention to the fermentation itself. The pH is a measure of acidity or alkalinity of a substance – some examples of common household items and their corresponding pH can be found in the graphic below.

A list of the pH of several common substances with a graphical representation of wort enzyme activity in a narrow pH range. Created by Alyson Lanciki.

As you can see from the graph on the right, a very narrow pH range is desired when mashing. Several enzymes present in the mash do their best work between pH 4.3–5.8, however temperature is also of great concern here.

Pro tip: Use a pH meter and acidulated malts or lactic acid (which does not impart undesirable flavors).

Pro tip: Check enzyme activity with a starch test (iodine) after a period of time before increasing the mashing temperature.

TEMPERATURE CONTROL

Enzymes originating from the malted grains cut the large starch molecules into smaller fermentable sugars, which yeast will eventually feed on to provide ethanol and CO2 as end products. Enzymes catalyze biochemical reactions, but they are fragile and can be damaged easily (denaturation) such as by raising the ambient temperature too high. Controlling enzyme activity during the mashing process is extremely important for several attributes in the finished product such as the body, mouthfeel, and of course the alcohol content.

Maltose, one of the main sugars found in the wort (liquid extracted from the mashing process), is also formed from the starches present by the enzymes α-amylase and β-amylase. While one cuts the larger starches into medium chunks, the other cuts medium sizes into fermentable sugars. Balancing the effects of α- and β-amylase is very important, otherwise you can make a sweet, thick beer with little alcohol or a very thin beer which tastes a bit like moonshine.

Pro tip: Use a sensitive (digital) temperature probe if possible and do not rely on built-in thermometers!

BUSINESS MEETS PLEASURE (AGAIN)

My friends in Herisau at the Competence Center for Ion Chromatography (CCIC) were kind enough to run some samples from the stout and porter, providing me with some great data. Ion chromatography can tell so much about beverages (and indeed many other things), and in this case, IC won again. You see, I sent 2 bottles for testing in Herisau, but switched the labels knowing that the Milk Stout would have quite some differences from the Smoked Porter.

Organic acids found by Metrohm ion chromatography in the M75 Milk Stout and M75 Smoked Porter. Data provided by Iris Reber (CCIC, Herisau, Switzerland).

Looking at the resulting organic acids analysis, the large peak at ~26 minutes (lactic acid) clearly comes from the lactose I added to this style! I will have to dig a bit further to understand what the increased methanesulfate could be from. There is always something new to learn.

Thank you to Iris, Manish, and Theresa for doing your very best. Next month, Stephanie visits and will join in my final Metrohm brew: Koning’s IPA. Stay tuned!

Metrohm Jubilee beer labels. Created by Alyson Lanciki.

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