I’m happy to announce that I will be presenting a conference on selected topics of espresso mechanics on the morning of Sunday, April 14 (8-11 AM) during SCA 2024 in Chicago ! While researching various topics and analyzing data sets for my upcoming book “The Physics of Espresso”, I have come to learn a lot and also stumbled upon some pretty surprising ways in which the styles of particle size distributions can affect the properties of espresso. I will be discussing some selected topics about which I have learned the most recently, with a data-rich, deep dive. Such topics will include: How puc ..read more

Back when I published my book “The Physics of Filter Coffee“, I started drafting what I thought would be the ideal dripper for filter coffee. I wanted the dripper to be cylindrical, prevent any bypass of water around the bed of coffee, use the most possible open filter area under the coffee bed, and have a valve to control the flow of water through the coffee bed. The reasons behind these choices were relatively simple: I wanted to have control on the flow rate to experiment with bloom time, allow for either normal pour-over methods or steeped immersions that could then slowly drip out by the ..read more

[Originally published on July 18 on my Patreon] Header photo credit: @coffeeandlucas, @mymedia.studio At this year’s Specialty Coffee Expo in Boston, I finally met Samo Smrke, a coffee scientist from whom I have learned a lot over the years, and who produces what are in my opinion some of the best scientific papers on the topic of coffee chemistry (e.g., on the topics of coffee degassing, coffee storage, and how roasting style affects the degassing). I told Samo about some of the weird observations I have made recently about astringency, which were on my mind because I could not figure out a m ..read more

Originally posted on Patreon on Oct 17, 2021 I’m excited to share that I have just figured out a detail about my puck preparation that seems to completely eliminate a problem I had with almost every single shot of espresso I had ever pulled so far. After you pull an espresso shot, you can knock out your puck in a plate and wait for a minute or two to see if the color of the puck is relatively even across its bottom surface. In my experience, decaf and medium to dark roasts do not show much of anything useful when doing this, perhaps because of the darker color, or because they tend to channel ..read more

I’m excited to announce I will give a 3-hours live class on the Physics of Coffee during the 2022 Specialty Coffee Expo in Boston ! I will discuss my most up-to-date understanding of the physics in play in both espresso and filter coffee, and what this means for the best methods to brew coffee repeatably and achieve your desired goals. This class will include some brand new data and conclusions, new questions and predictions, and we will do a live demonstration of a new dripper prototype that I think will be both geeky home baristas’ and WBC coffee competitors’ dreams come true. If you want to ..read more

In the past weeks, I have been experimenting with the AeroPress combined with the Prismo attachment, and I tried one small hack that produced a surprising result. I inserted a pasta strainer mesh like the one I described in my Stagg [X] recipe to increase the total open surface area under the AeroPress filter. As shown on the photo below, placing a paper filter directly on top of the Prismo’s metal filter will only allow water to flow through the tiny and sparse holes of the metal filter, and therefore more pressure will be required to achieve the same drip rate. When a paper filter adheres to ..read more

Reminder: as an Amazon Associate I earn small commissions from qualifying purchases made through the Amazon links below, which are identified individually. I have no association or commercial agreements with any products mentioned below. Some of Jame Hoffman’s late videos on the topic of the AeroPress (Amazon Affiliates link) have stirred a lot of discussion around this particular brewer. I highly recommend watching all three of his videos, because the tests and discussions he presented are of a very high quality. It is extremely rare for me to land on such a deep discussion about any coffee b ..read more

Header photo by Juan Silveira. A while ago, I read an interesting idea from Robert Mckeon Aloe on Matt Perger’s Telegram channel about measuring the total dissolved solids of a live espresso shot with the Decent DE1 machine, by comparing the output gravimetric flow measurements with a bluetooth-connected Acaia scale, to the input flow above the puck at the shower screen as predicted by the DE1. I think this is a really good idea in principle, but when I read this I immediately expressed worries that I didn’t think it could be done accurately yet because of the systematic inaccuracies with whic ..read more

Now that I have outlined the method by which I pull espresso shots with the EG-1 grinder and SSP ultra-low-fines burrs (or ULF burrs for short), I thought it would be interesting to compare them with a more classical espresso grinder like the Niche Zero. I do not yet have great data to show you exactly how the particle size distributions of these two grinders differ, because doing so will require measuring the very-fine coffee particles down to a dozen microns in size, something extremely hard to do with imaging methods like my grind size application. Sifting might sound like a good method for ..read more

Reminder: as an Amazon Associate I earn small commissions from qualifying purchases made through the Amazon links below. I have no association or commercial agreements with Weber Workshops or other products mentioned below. Now that I have gotten comfortable with pulling good-tasting shots with the Weber Workshops EG-1 grinder paired with SSP’s ultra-low-fines burrs, I think it is time for me to share my experience. The SSP ultra-low-fines burrs (I’ll use “ULF” for short) were not initially designed for espresso, because their explicitly stated goal is to minimize the amount of very fine coffe ..read more