Introducing Salamibot

Recently, I’ve been splitting my morning coffee at various brew ratios, measuring total dissolved solids (TDS) in the first part, and using this information to explore extraction dynamics using various equipment configurations. This method has a few limitations: Splitting a couple of coffees each morning, it takes a week or so to gather data for… Continue reading Introducing Salamibot

A Simple Model of Extraction

A little while ago, Jonathan Gagné suggested that I should take a look at the plot of extraction yield (EY) vs. brew ratio. His hypothesis was that we could fit a particular curve to the data in this plot which would give some insight into the extraction process. The model When we think in very… Continue reading A Simple Model of Extraction

A Closer Look at Tamping

For some time, I’ve assumed that the specific force you tamp with has little effect, as long as you tamp hard enough that the puck stops compressing. However, the results of a recent experiment led me to believe this might not be the case. To check this, I purchased a Normcore spring loaded tamper, then… Continue reading A Closer Look at Tamping

Scale Accuracy Issues

About six months ago, I picked up a cheap 0.01 g scale from Amazon. These go by a few names, but if your scale looks like this, then it’s probably the same scale: Over time, I’ve noticed something odd about the measurements I get from the scale. I usually weigh 18 g of beans for… Continue reading Scale Accuracy Issues

Modeling Extraction

In the academic literature, several models have been proposed for extraction of soluble components from solid coffee. Some of these models are very detailed. Some use computational fluid dynamics (CFD) to model fluid flow through the packed bed in three dimensions. One of my favourite models was described by Moroney et al. in their 2019… Continue reading Modeling Extraction