Doc Kieft Monmouth Summer Research 2019

Coffee Project

Project Overview

For this project I worked with Brad and a fellow student,Josie Welker, to determine the caffeine levels in different samples of coffee. For this project we made caffeine standards to compare the samples to. The following link describes how we made these standards.

Caffeine Standards

Making the Coffee

To make the coffee for the samples, 2.6 oz of beans were weighed out. These beans were then grinded, and 38 g of the beans were placed into a pourover filter. Then, 640 g of boiling water were poured over the grounds, allowing the grounds to bloom as needed. This process was done with both L0 and L5 beans.

After this first batch of coffee was tested, we discovered that the coffee samples were too concentrated for our standards, so we cut the amount of beans used to 30g. In this batch we also made a sample of 15 g of the green coffee beans with 320 g of boiling water. We used a 0.45 micron filter and syringe to filter the solution into the HPLC vial to ensure there was no particulate matter present.

Instrumentation

After making the standards, we tested the standards using the HPLC to see where the peaks were for the different concentrations of caffeine. The following link goes into more depth about working with the HPLC.

HPLC

Once the standards were tested, another HPLC trial was done including the L0 and L5 coffee samples.

An additional HPLC trial was done with coffee that was not as concentrated. This set included L0, L5, and the green coffee bean samples.