Reflections on Coffee Iced / Cold

Since Seattle's mini heatwave of last week, I (Nate) have been musing on various delicious ways to consume cold coffee.

After poking around the net, the most useful post I've found on the subject is an August '09 post from Daniel Humphries' blog. Relevant post here.

I can't improve on Daniel's lazy man's cold brew, so I'll repeat it here verbatim:

1. Brew a pot of French press at 140% strength (that's 84 grams to the liter, or exactly 12 standard seven gram scoops in an 8 cup press)

2. Pour immediately over ice

I like that Daniel's method allows a quick 4 minute iced coffee preparation and allows the coffee to cool quickly without becoming diluted. The strongest part of the blog post, though, is Daniel's description of the volatile organic acids that extracted from the grounds during a hot brew process. These are a subset of the dissolvable flavor compounds referred to in my recent 2 part post on brew colloids and the Coffee Catcher (1 and 2). Organic acids in coffee tend to stand out as flavor highlights on the palate, but are fragile and decompose rapidly. Decomposed acids taste bitter, and this is why Daniel recommends a hot brew followed by very rapid cooling to preserve that fleeting complexity in the cup.

The other major cold brew school is toddy. The moniker comes from toddy equipment maker Toddy Cafe. Making toddy is easy: mix a relatively high dose of coffee (at least double normal, Toddy Cafe recommends a quad dose) with room temperature water and brew for at least 12 hours. Dilute to taste and serve. Because temperatures never approach those needed for organic acid formation, toddy coffee remains smooth and approachable regardless of brew time, although the trade-off is significantly reduced flavor complexity.

Here's my question. Why does a toddy brew require a massive updose? Extraction may be slower, but total extraction of coffee compounds during the cycle seems comparable to a hot brew. Caffeine content is certainly there, as I can attest after a recent cup of Toddy at Aster - and that's after dilution. Ice dilution should be even less of a factor with room temp coffee than with a hot brew, so my intuitive sense would be a dose in the 120% range. If extraction rates and dilution aren't in the picture, what else is going on to justify double to quadruple doses?

I'm a card carrying advocate of the "if it tastes good, it is good" school, so if it just tastes better, that's a good enough reason for me. My question, though, is why? And also, has anyone tried brewing toddy at normal strength for comparison? Comments welcome.

Blog Highlight: "The Average Seattleite"

I'd like to start this short week by pointing out an interesting emerging coffee blog on the Seattle scene. Michael Frank, a local SPU student, is making the rounds of Seattle's coffee shops, Disloyalty Card in hand.

I found Michael's writing to be refreshing, upbeat and frank. His reviews go well beyond the annoying "no outlets by my seat!" type and are satisfyingly focused on the coffee served. It's also refreshing to see someone blogging as they go - and as they learn. Reviews up so far include Aster, Trabant, and Fonte. Before Michael discovered the Disloyalty Card, he also covered Bedlam and Roy St.

Disclaimer: Michael Frank also mentioned the Coffee Catcher in an early post about learning the French press at our recent launch party. Always glad to see new FP fans!

Keep up the good work Michael! Looking forward to reading more reviews soon...

creative uses for the French press?

This blog post from www.kitchn.com sure got our brainstorm wheels a'churnin




Q: This question is about French press coffee makers. I'm sure that I've seen these used on Iron Chef (or other places?) for purposes other than coffee, such as infusing broths with aromatic herbs.

I'm sure there are other ways to infuse a broth with a particular flavor, but this just appeals to me on a visceral "that seems pretty awesome" level. What's out there in terms of alternative uses for my French press — uses other than tea or coffee. Any ideas?

Everyone else, have you thought of this? Talk about outside the box...

thoughts on a controlled study of brew times

Last month a new controlled study of brew times in French press coffee was released.  Conducted by Daniel Drazenovich, Chief Technical Engineer for the micro roastery Old Wwworld Cafe, the process and findings were quite interesting and worth a read. (See, "Perfectly Timed French Press Coffee".)


The Coffee Catcher's Nate Jones had the following thoughts on the study:

"It certainly makes intuitive sense that the surface area of grounds exposed to water coupled with the total volume of grounds should affect the timing of coffee brewed.  Personally, I think the 200 degree pour is a bit on the low side, but I have no reason to supposed that that would comprehensively skew the results.

"This reminds me of an all day experiment I've been wanting to do involving brewing French press coffee by visual cues. I do it, and John [Custer] does it, but I haven't had a chance to figure out exactly what I'm reacting to in terms of sight, smell or perception of time that tells me when to press.  I think the color of the crust on the top of the coffee does change as the brew continues, perhaps as oil extractionslows, but I can't quite verbalize those cues yet. Anyway, this chemistry-heavy approach reminded me that sometime soon I'd like to do a controlled direct-perception series of brews and evaluate the results."