How pure is your CO2? Oxygen is the enemy of beer and we do everything to try to reduce it throughout the brewing process. This simple device measures the purity of CO2 by using a concentrated NaOH solution that absorbs CO2 as carbonic acid. The higher the burette fills up, the purer the CO2 since air can’t be absorbed by the NaOH solution.

Full Sail Brewing Company, Ridiculously Tasty India Pale Ale. 6.0%. Very mild IPA. Hops are a bit piney with a slight bitterness on the back end. Great golden amber color and moderate carbonation. This is the type of IPA you can just sit back an relax with, very smooth and mild. by southshorebrew

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HPLCs (high performance liquid chromatography) are used in brewing labs to determine the amount flavor and bittering compounds in hops. Namely, alpha and beta acids. HPLCs can also be used to determine sugar composition in beer and wort.  This can help diagnose issues with stalled fermentation and determine if it’s a yeast issue or mash issue.


Samples being shaken for bitterness analysis. The two phases have to mix for 15 minutes for all of the iso alpha acids to migrate from the beer into the octane.

It’s a gas chromatograph! GC’s are used quite heavily in brewery labs to quantify the amount of certain off-flavors found in beer. One of the most notorious is diacetyl - the butter/butterscotch flavor that usually signifies that a beer was filtered too early in fermentation. The same goes for acetaldehyde - which is the green apple/jolly rancher taste. It’s nice to have a machine to do the sniffing for you and that’s what the GC does.


Yay bottling line! It’s damn near hypnotic. You’ll notice the foam-over on the bottles after they have been crowned. This foam over is intentional and helps to purge the headspace of air. A small jet of deaerated water is injected into the bottle and causes a slight foam over.


Brewers yeast eats sugars and produces alcohol - that’s well known. Yeast also gives off CO2 in rather copious amounts during primary fermentation. You see that here as part of the blow off of a 400 bbl (12,000) gallon fermenter

Measuring alcohol in beer is a complex process. One of the older methods involves using an ebuilliometer to calculate the difference in boil temperatures from water to a ethanol/beer mixture like beer. The easy way to measure alcohol by volume is to use an analytical tool like the Anton Paar Alcolyzer (pictured). It uses NIR technology to determine the gravity of a solution.

This is saccharomyces cerevisiae (A.K.A. ale yeastunder darkfield at 40x magnification.  Ale yeast typically ferments around room temperature (62-75 deg. Fahrenheit) and produces more fruity esters than lager yeast.  

There are lots of sub-types of ale yeast found all over the world.  The most famous strains are from Belgium which produce lots of fruity esters (think of the banana flavor), as well as spicy phenolic compounds which give a bubblegum flavor.  Esters come via esterification reactions of different alcohols produced by the yeast (isoamyl alcohol, isopropyl alcohol, etc.) reacting with acids present in the beer.

Brewers make wort, yeast make beer!

The skunking of beer is a great example of free radicalization. Remember o-chem? Yeah, I try to forget it too.

Light reacts with riboflavin and iso alpha acids present in beer and degrades into methyl mercaptan - a stinky thiol compound. It’s also one of the compounds that are present in the stink glands of skunks. Ergo, skunky flavor!

Some bigger breweries in Europe export pre-Skunked beer to the US because they think we like the Skunky flavor. They actually expose their green glass bottles of beer to banks of UV lights to give beer that skunked badness.

Remember to buy beer in brown glass bottles or cans to avoid the skunk!