Beer is a complex creation.
When we brew a beer, we depend on our water, malt, hops, and yeast to act a certain way and produce certain results. On good days, our ingredients are our best friends. However, every now and then, something changes with one of our ingredients and impacts our beer in the process. We have experienced this once or twice in the past with certain hop varieties, but we have always been able to quickly identify any inconsistencies and deal with them promptly.
Recently we were faced with a much more mysterious conundrum. Over the past couple of months we have been noticing some particulate matter in many of our batches of Lone Pine IPA. We had previously noticed a similar issue in our Red IPA, “I the Mountain and the Leprechaun Flute” and our Sour IPA which we brewed with Stone City, “An Ale of Two Cities”. These particles had no impact on the flavour or aroma of the beer, nor did they affect the texture of the beer. However, they created a dissatisfactory visual effect that we weren’t crazy about. We spend a lot of time on perfecting the overall sensory experience that a drinker has when they try a Sawdust City beer, and this includes the appearance just as much as the flavour and aroma. We determined that this particulate, which looks like snowflakes floating in the body of the beer, was caused by the coagulation of excessive protein content in the beer. We initially believed that the issue was largely caused by our centrifugation process and immediately stopped using our centrifuge in the transferring process of Lone Pine. However, the issue persisted, leaving us even more baffled than before. After some serious investigation, we noticed that the three beers which were exhibiting the issue had two things in common:
- All three beers used a malt called Caramunich, and
- All three beers were very heavily dry-hopped.
Other Sawdust beers which were heavily dry-hopped but didn’t use Caramunich didn’t present the issue, and other beers which use Caramunich but weren’t heavily dry-hopped didn’t present the issue. This has led us to the conclusion that the issue is being caused by a combination of these two factors.
We are not food-scientists, but here is our working theory:
All malt contains proteins, and different malts will contain different levels of protein. These levels can vary from malt variety to malt variety, and also from year to year and batch to batch. These proteins provide some of the body and structure of the beer and also act as nutrients for the yeast during the fermentation process. However, an excessive amount of these proteins can have undesirable effects, including chill-haze - a phenomenon that causes chilled beer to develop a significant and unexpected haze. Our theory is that the Caramunich malt which we have been using in Lone Pine contains an excessive amount of proteins, which are not being broken down throughout the brewing process (despite employing a process known as a protein-rest), and are therefore present in higher than normal levels in the finished beer. If that is the case, then why are we not seeing this phenomenon occur in beers which use Caramunich malt but are not dry-hopped?
That brings me to part two of the theory:
Another one of the compounds that is found in all beer is tannic polyphenols, or simply “tannins”. Tannins are found naturally in plant material such as barley and hops, two ingredients which we rely on very heavily. The presence of tannins in beer is desirable as they help to give the beer more character and support. Much like in wine, tannins can play a crucial part in the overall impression of a beer. However, as brewers we try to limit the overall amount of tannin content in our beer as an excess can have an undesirable impact on the finished product. For one thing, excessive tannins can produce astringency, which is a mouth-drying sensation similar to bitterness. If you’re looking for an example, think about an over-steeped cup of black tea. The drying, puckering effect that you feel in your mouth is due to tannin-induced astringency. Tannins also play a very interactive role with proteins in beer. Throughout the brewing and fermentation process, tannins bind with proteins to create large, complex compounds which are typically removed from the liquid before the final packaging procedure. However, if the protein content of a beer is excessively high, and tannins are introduced into the equation to a large degree and late into the conditioning process, they can bind together and create large haze-forming particles which materialize in the finished product. This process is exacerbated by cold-temperatures, as it triggers these compounds to coagulate together, therefore creating larger and more noticeable particles.
So, that is our theory. We are quite confident that we have determined what the source of the issue is, and we are taking aggressive steps to correct it. Regardless of what our final conclusions are, whether it be a temporary malt substitution, or a change in our process such as an increased conditioning period, you can rest assured that Lone Pine continues to improve as we work to perfect it.
In the meantime, if you encounter a can of Lone Pine with these snowflake particles, know that they come in peace.