Titrations need four things: sample, acid, base, and an indicator. You add acid to a base and indicator-infused sample and by knowing the exact volume of acid added to neutralize the basic solution and change from pink to blue, you can determine how much of a substance is in solution. Titrations are used to determine the total amount of hardness, calcium, and alkalinity in brewing water. This is…
Without yeast there would be no beer. Here are two pictures from our automatic cell counter. The one on the left is a brightfield picture of our house yeast. The one on the right is our house yeast stained with a fluorescent dye called propidium iodide. The dye will bind with non-replicating DNA in yeast cells. Basically, if you see a glowing cell, it’s dead. This is how we determine how viable…
This is a High-Performance Liquid Chromatograph (HPLC). This awesome piece of analytical equipment can measure the concentration of different compounds present in beer, wort, and hops. We use it to measure the concentration of humulone, cohumulone, lupulone, and colupulone in hops. These are collectively known as alpha and beta acids in brewing terms. The alpha acids (…
UV-vis spectrophotometers are the swiss army knives of brewing chemistry because of the sheer amount of compounds it can analyze for and for the cheaper price tag.
Spectrophotometers (“specs” for short) are used to measure the amount of iso-alpha acids in beer, which gives you IBUs.
Specs can also measure, in wort and beer, the amount of free amino…
This is a Gas Chromatograph (GC for short). It separates volatile compounds and measures the concentration of those compounds using various detectors. Brewing scientists can use a GC to find the amount of various off-flavors present in beer.
One off-flavor that is looked at the most is 2,3 butanedione – more commonly known as diacetyl. Diacetyl is a vicinal diketone…
The grid like pattern on the Stochasticity Project Grapefruit Slam IPA bottle label is a two-dimensional random walk. Random walks explain observed random behaviors and processes and are the most elementary way of showing recorded stochastic activity. Random walks allow us to find patterns in behaviors and processes that seem random. In short, randomness isn't really that random after all.
This image shows how we extract iso-alpha acids from beer in order to find out how many IBUs are present. We acidify the beer sample in order to make the iso-alpha acids (IAAs) less soluble in beer and more soluble in the non-miscible iso-octane. The iso-octane will extract the IAAs and we will use our UV-Vis spectrophotometer to measure the absorbency at 240 nm in order to find out how many IBUs…
Triangle testing is an essential part of our sensory program. It involves a set of three samples - one sample is a test and the other two are experimental controls which are presented blind to the taster. The goal for the taster is to try to determine which sample tastes different from the other two. This test is an important, unbiased way of determining if a change in the brewing process…
The vanilla compounds from the spirit barrel combine with the fruity esters from the Belgian yeast, and in the case of this particular beer, some tropical fruit and citrus notes from the hops that we chose for the whirlpool addition. The furan compounds in the bourbon barrel will give some light caramel and toffee notes to the beer, and a slight perceived sweetness. All this combines…
A problem that all brewers face is managing and eliminating off-flavors. For the first post of this series, we'll take a look at DMS.
What is it?
DMS (dimethyl sulfide) exhibits itself as a canned vegetable or creamed corn flavor in beer.
How does it form in beer?
All malt contains a variant of the amino acid methionine called S-methyl methionine (…
