YIC: Temperature-dependent Flavor Determination

*This is part three of the Yeast from the Iron City (YIC) series. For sampling, media, and plating information check out Part 1, and for Isolation Part 2.

Now that we had isolated our very own yeast strain, it was time to pray to the many gods of beer and hope that it would result in something drinkable. We wanted to use a fairly simple recipe to make sure the yeast would be the star player in terms of flavor. To determine the temperature that resulted in the best flavor profile (see ester post), the wort was split into three 1 gallon batches and placed under 3 different temperature regimes (Cold 45 °F, room temp 68 °F, warm 72 °F). The recipe is in the style of a Belgian pale ale and is as follows:

Fermentables
5.5 lb Light DME
.25 lb Caramel 40
.25 lb Caramunich
Hops
0.5 oz Galena       30 min
0.5 oz Hallertauer 15 min
.25 oz Chinook      5 min
Yeast
The Fringe
Estimated
OG: 1.050
FG: 1.018
ABV: 4.2%
IBU: 40

Starter:
A starter was made from the isolated yeast by going from a 100 ml starter to a 1 gal starter. The large starter was then allowed to ferment and settle. The liquid was decanted off until only approximately 2 L remained. I then swirled the solution to bring the yeast back into solution and filled 6 sanitized White Lab Vials. The remainder was then pitched into a 500 ml starter for this recipe.

Brew Day Notes:
The day went on without a hitch. Heated 4 gallons of water to 155 °F and steeped the grain for 30 minutes. The grain bag was then removed and the DME was then whisked in. The wort was then brought to a boil and the hops were added as is shows in the recipe. The wort was then cooled with the immersion chiller to 70 °F. The batch was poured into a bottling bucket for easy measuring and topped up to 3 gallons with filtered water. The batch was split between 3-1 gal jugs and 160ml of stater was added to each batch. The jugs were left at room temperature (68 °F) until fermentation had begun (about 12 hours). They were then placed at their respective temperatures (Warm, Room, and Cold temperatures).

It took approximately 2 weeks both the warm and room temperature batches to complete fermentation. The cold batch took about 3.5 weeks total. The vessel needed to be removed from the fridge for fermentation to begin again and then was placed back into the fridge. After fermentation seemed to slow the vessel was left at room temperature to finish fully and to clean up diacetyl.

Measured 
Vol: 3 1-gal
OG: 1.051
FG: (Warm-1.018; Room-1.017; Cold-1.018)
ABV:4.3%

Tasting:
1-28-14:
Warm (72 °F): Pours copper with frothy white head. Aroma of clove, spices, slight fruit, slightly dry. Taste is slightly sweet up front with a bitter finish. Slightly tart. Very clean taste compared to the aroma. Light body.

Room (68 °F): Same appearance. Aroma of slight fruit otherwise clean. Taste is light grain, sweeter front than the warm with a slight bitter finish. No noticeable tartness. Light body.

Cold (45 °F): Same appearance. Aroma of light fruit, grain, Belgian spices, caramel, it is the sweetest of the three. Slight banana notes. bitter sweet finish. Light body.

Overall: This style and recipe was not exceptionally great, but we expected this one to be very mild in flavor because of the very simple light grain bill. The yeast strangely seems to be quite clean producing slight Belgian notes but otherwise no funk or noticeable off flavors. Amazingly this seems to be the case across the entire range of temperatures. The only real noticeable effect of the temperature was a longer fermentation (obviously) and the beer ended at a slightly higher FG and lead to a slightly sweeter beer overall at cool fermentation temperatures. This was quite surprising to us to have a first attempt wild yeast that both attenuated relatively well (64%) at all three temperatures and did not impart any crazy off flavors. It would be interesting to pitch this yeast into a more complex Belgian style where the grain bill is more complex, like a Dubbel or a Quad, especially to see how it handles the higher levels of alcohol.

Currently, the yeast is being worked up in the lab to determine what genus and hopefully species it is so that we can better characterize it. Updates will follow!

Beer Consumption Transcends Demographics (mostly)

A recent trip to Europe got me thinking. Wait, wait, before you begin the eye rolls or the sighing, this is not yet another post on the wonders of European travel or a nose lifting espousing of European beer. It was my first trip to Europe and it got me thinking about beer consumption rates and how they compare to the United States and of course my science training took over. I wondered what factors could contribute to or go hand in hand with beer consumption rates? Could it be as simple as the number of breweries, the population per brewery, per capita income, or could it be seasonal temperatures? Obviously there are a multitude of factors at work in determining the impacts on beer consumption, but I was surprised by some of the results.

I started out with looking at the top ten per capita beer consumption countries. It was no surprise that the top ten looked like a line up for a 19^th century polo match, affluent (mostly), white (mostly), and European or former European colonies (Australia, Venezuela). I also looked at some countries with large production rates such as Belgium, Netherlands, and Canada as well as the bottom ten countries in the top 50 for per capita consumption. Some of these countries included Japan, Angola, Namibia, Mexico, and the Scandinavian countries. I hoped by adding some non-European countries that I might see some different trends, but again I was surprised with what I found.

When I began looking at some of the correlations (a mutual relationship or connection between two or more things), I was really surprised by some of the factors that I expected to have an impact on per capita beer consumption had no apparent relation. I was also surprised that production rates, including the number of breweries and population per brewery, had no correlation with per capita consumption rates. Total beer consumption was positively correlated to the number of breweries, total beer production, and summer temperatures. I would have thought winter temperatures may have had a positive correlation to consumption as I know I tend to feel like drinking more in winter.  Interestingly enough as beer consumption increased dairy consumption decreased, but I think this was largely due to countries at the bottom of the top 50 which had low dairy consumption rates (Angola, China, Namibia). When I looked at just the top 15 countries I didn’t see any correlation between dairy consumption and beer consumption rates, but again these were mostly European countries that have relatively the same dairy consumption rates.

The most surprising thing was that I didn't find any relationship between beer consumption rates and income. Studies have found a relationship between income and consumption rates ^(1,2) but those studies mainly looked at in-country numbers or regional comparisons. Even by looking at the bottom of the top 50 list, which has some relatively poor countries, I still didn’t see any correlation between income and beer consumption. Excise taxes also didn’t have any relation to beer consumption. Scandinavian countries have some of the highest excise taxes on alcohol but also have very high per capita consumption rates.

The only factor that seems to be a common thread is being associated with Europe. Most of the countries with the highest per capita consumption rates are European or were colonized by Western European countries. Beer may not have been invented in Europe but that is where it was perfected and has been brewed in its modern form since at least the Dark Ages. Some have made the argument that without beer (and wine) European civilization may not have been as successful as it was without safe drinking water (i.e. boiling/alcohol). Say what you will about European colonialism, but know that we have it to thank for the spread of beer globally. Prost! 

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1. Österberg, E.L. 2011. Alcohol tax changes and the use of alcohol in Europe. Drug and Alcohol Review. 30, 124–129.

2. Freeman, D.G. 2009. Beer in Good Times and Bad: A U.S. State-Level Analysis of Economic Conditions and Alcohol Consumption. Beeronomics Conference, Leuven, Belgium, May 2009

Data Sources

http://vegetarian.procon.org/view.resource.php?resourceID=004716

http://en.wikipedia.org/wiki/List_of_countries_by_milk_consumption_per_capita

http://www.st.nmfs.noaa.gov/st1/fus/fus11/08_percapita2011.pdf

http://bovbeers.wordpress.com/2011/07/02/number-of-breweries-worldwide/

http://www.brewersofeurope.org/docs/publications/2012/stats_2012_web.pdf

http://www.fin.gov.on.ca/en/tax/bwt/rates.html

http://www.caseysbeer.com.au/?page_id=97

http://chartsbin.com/view/1491

http://www.climatemps.com/countries-a.php

http://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)_per_capita

http://apps.who.int/gho/data/node.main.A1184?lang=en?showonly=GISAH

http://www.ttb.gov/tax_audit/atftaxes.shtml