What’s Water Got to Do With It?

Our temporary yeast propagation and laboratory set up in the kitchen.
Our temporary yeast propagation and laboratory set up in the kitchen.

After a five month brewing hiatus we are preparing to brew! We decided that our Amber Ale, is going to be our inaugural Colorado brew. We last brewed this in March 2016 in Davis, CA. We were happy with the recipe we developed and already have the complete grain bill. We went to Hops & Berries South in Fort Collins to pick up yeast (Wyeast 1450) and hop pellets (Magnum, Cascade, Amarillo). It quickly became clear that we would have to deal with some unintended modifications to our recipe. Here are some of the recipe and environmental changes that we will be attempting to compensate for. Beware, this post is biochemistry heavy.

Recipe changes

  • Hops & Berries was out of Cascade pellets, so we purchased whole cone. This is going to lower our utilization rate because the lack of processing means the lupulin glands (source of bittering and aroma compounds) were not ruptured. When we last brewed this recipe, the Cascade pellets were added when heat was removed; with the expected lower utilization rate, the whole cone Cascade will be added with five minutes left in the boil.
  • Hops & Berries also sold out of the the WYeast 1450, but offered WYeast 1272 American Ale II as a substitute. 1450 is a blend of three different yeast strains, of which 1272 is one. According to the knowledgeable staff at Hops & Berries, 1272 will result in a drier finish than 1450. Increasing the mash temperature may help counteract this flavor characteristic imparted by the yeast. The flavor profile (contributions of esters, higher alcohols) of this yeast also tends towards dark fruits, such as dried cherries.

Water

This is the biggest change to our brewing. The water in Davis, CA was ‘hard’, alkaline (pH 8.2), and filled with various metals (arsenic, boron, manganese, hexavalent chromium). This link will take you to the Davis, CA water chemistry report; check out all the notifications of ions exceeding limits. The water analysis of Loveland, CO (bonus points for having a quick link on the city services website for those who rely on water quality and composition for their craft) indicated soft water, approaching neutral (pH 7.4), and few metals reported.

Why the difference in water quality? During the time we were there, Davis’ water source was multiple wells. Each well’s mineral composition is based on what is leached from the rocks, soils, and human activities in the area. If you follow the link provided above (Davis water), you will see that the values for various analytes fluctuated widely. Loveland’s water comes from reservoirs filled by snow melt from Rocky Mountain National Park. Compare the Davis and Loveland analyses. The water in Loveland in consistent month in and month out for the period it was tested. We are so glad we are not drinking water from Davis, CA anymore.

What do we predict the effect of the change in water is going to have on our beer? From personal experience, the water in Loveland tastes and smells much better than the water in Davis. That will immediately eliminate off odors and flavors from our beer that are from the water. Less chlorine will reduce the possibility of chlorophenols forming; these compounds can impart a medicine or band-aid like aroma and flavor. Loveland’s lower water hardness (less calcium and magnesium) may have a negative impact on enzyme activity (calcium stabilizes and activates alpha-amylase and magnesium is a cofactor for a variety of enzymes in yeast). However, the lower pH of the Loveland water may improve enzyme activity, negating the negative effect of low calcium concentrations. Overall, we think the differences in water chemistry are going to be a net positive for our brewing in general.

Altitude

Our elevation in Loveland, CO is 4984 feet, which we are going to say is close enough to a mile high (5280 feet). So why do we care that we are a mile high? At sea level water boils at 100 degrees Celsius and the boiling point decreases roughly 0.5 degrees Celsius for every 500 feet elevation gain. So, at Loveland’s altitude, the boiling point of water is approximately 95 degrees Celsius.

Why do we care about water boiling at a lower temperature? The off flavor dimethyl sulfide (DMS). DMS has a low threshold (easy to detect) and has an odor of canned or canned creamed corn. Not usually a flavor that is found in beer style descriptions. Please bear with the next paragraph; it is heavy in biochemistry and brewing science to provide the necessary information which will help convey the impact water’s lower boiling point.

The precursor to DMS is S-methylmethionine (SMM), which is produced during barley germination. Without germination, we would not have malt, so we cannot eliminate germination to decrease SMM. At 100 degrees Celsius (boiling point at sea level) the half-life of SMM is approximately 40 minutes. Thus, after 40 minutes, approximately 50% of SMM present would be converted to DMS. If one was boiling with vigor for 60 minutes, then 65% of SMM would be converted to DMS. DMS will be volatilized during a vigorous boil, carried off by the vapors, and will not be present in the wort (which would carry over to the beer).

95 degrees Celsius, the half-life of SMM increases to 80 minutes. So to convert 65% of the SMM to DMS, boil time would have to be increased to 2 hours. A longer boil time will increase evaporation, increase the Maillard reaction, which will increase melanoidins (flavor and color components) and potentially caramelize more sugars. Compromising and setting the boil time to 90 minutes would lessen evaporation and Maillard reactions, but approximately 45% of the original SMM amount would remain. Which could then be converted to DMS during the whirlpool stand. Without a vigorous boil, the DMS will not be volatilized and will carry over into the finished product. It’s just complicated.

Summary

We are going to just brew and see what happens. Likely modifications will be a higher mash in temperature and a 90 minute boil. Everything is about compromise. We have multiple variables changing in this brew and will find out if our compromised produced a decent beer in approximately one month.

Here’s a picture of the WYeast 1272 American Ale II starter culture under the microscope after 24 hours. A reward for reading that science geek out that proceeded the summary.

Wyeast 1272 American Ale II starter culture viewed under 800x magnification.
Wyeast 1272 American Ale II starter culture viewed under 800x magnification.

 

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