... and some interesting comments from him about pour-over at http://scottrao.com/blog/some-observati ... and-pours/
- pre-infuse (which he calls pre-wet, which is semantically more accurate) at 3:1 and stirring with an implement, e.g., 12g coffee, 36 g water, a spoon;
- likes Clever Coffee Dripper;
- doesn't like Chemex;
- the spin (seven second video)

Most of the references to the "Rao Spin" don't involve moving the filter holder but instead refer to when you have a good pour the water spins on it's own on the way down, maybe after bumping the filter holder. Even still, I may have to try a bump or moving the filter holder to settle the grounds during final drawdown to see if it helps.

Yup, I realize now that probably comes from the Perger/St. Ali V60 video where it is stated, "Rao spin achieved via pour" (italics mine).

I tried spinning the whole V60 this morning and also going with 3:1 instead of 2:1 (I already stir the grounds during pre-infusion/pre-wetting). Works as advertised - flat bed left, no high-and-dry grounds, and the coffee tasted like more was extracted. I have no idea whether the result tasted 'better' or not, as I think that would require equalizing extraction yield (between the cups made by different methods).

When using a coffee with less gas, I find it hard to achieve a rao spin. I look more for a flat bed of coffee after extraction, I feel like this is a better indicator for me. Coffee still tastes great.. I sort of consider this spin thing one of those pointless coffee visuals. Kind of like bottomless portafilters (though, that certainly has more merit in my book). Not all ugly bottomless shots taste bad, right? I might be wrong.

Scratch that.. I just read the post and I've been educated.. thinks for linking.

I read that blog the other day after spending 8 hours at my local Apple & Pumpkin Harvest Festival, killing 8+ gallons of water doing 8oz pour overs.

Almost nothing of what he says in that post correlates with my experience:

I own a Fetco CBS-61H batch brewer. It's great. I bring 3 gallons of pre-brewed coffee with me every Saturday and Sunday to my farmers markets. But since I started doing single cup pour overs, my customers prefer them to the batch brew and are willing to wait 3 minutes for a cup of coffee rather than grabbing a quick cup from the Luxus. I do as well. I've been bringing only one dispenser lately and dumping half.

I do not pre-wet. I read the instructions on the Hario V60 filter package that specifically state in Step 3, "Make sure the water does not come in direct contact with the paper"



So just how do you do a pour over with having the water come in direct contact with the paper? Good question, I thought.

So I've been practicing the Kono drip pour technique. Rao claims "The main advantage a V60 or Melitta filter is that, when using the right filter size, a barista can add all of the post-prewet water quickly, in one steady pour. Pouring all of the water at once, instead of in stages, allows the barista to keep the slurry temperature high enough to guarantee crisp, non-sour acidity every brew. I've had tasty V60s that had been poured in stages, but more often than not, brews poured in stages have had soggy, sour acidity indicative of low-temperature extraction."

I add water drip by drip, slowly allowing the bloom to grow from the center outward, never letting the stream touch the paper and it works wonderfully. No sour, under extracted flavors at all. If anything, the slow pour technique results in a smoother cup. I think two factors might be at play here: First, if your pour hits the paper, then water will more easily wick down the filter and bypass the grounds. Second, coffee contains over 1000 chemical compounds. Some taste wonderful, some resemble turpentine. For the same reason cold brew tastes so smooth, I think the yummy flavors come out at lower temps and earlier in the extraction, while yuckies come out at higher temps and take longer to release from the grounds. By slowly pouring water into the ground bed the water is slowly cooling so by the end of the 3-minute extraction, the temp is a bit lower and therefore leaves some yuckies behind. Not very technical, I know, but you get the idea.

Anyway, I've been pouring lots of coffee like this for 3 weeks now and have not had a single complaint. Quite the contrary. I've gotten at least 2 dozen "this is the best coffee I've ever had".

Also, he disses naturals in a big way:

Scott Rao says:
October 10, 2016 at 2:30 pm
Hi Sam,
I personally don't like them, but I don't judge those who do. My real complaint about naturals, though, is that 95%+ of naturals are either dirty (old school naturals) or one-note coffees. Those qualities antithetical to the things most of us have been trying to accomplish in modern coffee: highlight terroir, and flavor nuances, and offer coffees with interesting character.

I love naturals and prefer them to washed coffees. I find them more complex, he claims they are one-dimensional. I think roasting them in a drum roaster can be problematic, since the fruit can scorch when contacting a 450* pre-heated drum. I air roast and maybe the convection heat is more gentile.

He also doesn't like the Chemex claiming the pouring in stages and slow draw down result in very low temperature extractions. I use a Chemex every morning and absolutely love it. I just started using the same drip, drip, drip technique as with the V60. By the time I'm done with the pour, I give it a little swirl and get a nice, perfectly flat ground bed. It's possible the lower temps enhance the brew process, just as the Kono drip does. As far as the channeling in a Chemex, why wouldn't the "Rao spin" work just as well as a V60?

My guess - guess - is that a lot of it has to do with the source coffee and roast level - context, in other words.

Rao is coming from a space where coffee never comes close to seeing second crack, even with development time ratios of 20+%, etc. Do a Kono low-temp drip with that roast and the results are not good; in my experience, under-extraction is the inevitable result.

OTOH, if I take a roast done to Kissaten levels - well into or past second crack (with no oils appearing), then I have found a Kono drip delicious, and a Rao/Perger style extraction full of an over-whelming bitterness/dryness.

... and, perhaps not surprisingly, each style, when matched to the relevant roast level, has given me similar TDS readings.

YMMV.

Lots to digest in that post -- I agree with some and disagree with more.

I've never seen any reason to think that Perger's "Rao Spin" (meaning a swirling drain of water through the grounds due to some combo of pour technique and coriolis force) would benefit extractions in any way. I get it sometimes but have never bothered to target it.

I do like Rao's suggestion to swirl the brewing cone a bit to settle the grinds after pouring. Maybe we should call it the "Rao Swirl" to keep things straight? And stirring the pre-wetted grounds is a great way to make sure they are evenly saturated with water.

As to the rest, I get pretty good brews out of Chemex and great ones out of v60s. By comparison, my Bonavita does pretty well but its best brews aren't at quite the same level. In a cafe environment I can see the case for using batch brewers for more consistency, especially if it is hard to keep highly trained staff on hand due to turnover. I have mostly stopped using Clever-style immersion drippers because although they make very sweet brews I find that I lose some of the aromatics and subtler notes with them.

He has a whole theory at work here praising temperature stability in brewing which I fundamentally disagree with. Falling brew temperature can help you get sweetness out of a coffee without over-extracting it. Open topped cupping brews taste fantastic, for instance, but they are the opposite of temperature stable. Lever shots are so good in part because the group progressively sinks heat over the course of the extraction, which works in tandem with the falling pressure to take off the harsh notes that creep in towards the end, leaving a sweet & clear shot.

As to naturals, I wildly disagree with him. Yeah, badly prepped naturals are gross, but there is terrible washed coffee out there as well. Some of my favorite coffees are dry processed -- just this month I've had the Yemen Red Haraaz, the Panama Elida Natural and the Finca Kilimanjaro Natural in heavy rotation.

baldheadracing wrote:My guess - guess - is that a lot of it has to do with the source coffee and roast level - context, in other words.

Rao is coming from a space where coffee never comes close to seeing second crack, even with development time ratios of 20+%, etc. Do a Kono low-temp drip with that roast and the results are not good; in my experience, under-extraction is the inevitable result.

OTOH, if I take a roast done to Kissaten levels - well into or past second crack (with no oils appearing), then I have found a Kono drip delicious, and a Rao/Perger style extraction full of an over-whelming bitterness/dryness.

... and, perhaps not surprisingly, each style, when matched to the relevant roast level, has given me similar TDS readings.

YMMV.

Only one of my coffees sees 2nd crack, and that at only about 10 seconds in. I range from 2-3 minutes development and 20-25%. 3-minute roasts about 20 seconds before 2nd and 2-minute roasts, about 45 seconds before? Drop temps between 415 and 428*. So nothing is overdeveloped, but nothing is too light either. I find lemon and pink grapefruit to be highly undesirable flavor notes.

I'll have to try a very light roast and experiment with higher temp flooding pours vs dripping. I have compared my normal roasts using both methods and the clear winner every time is the slow drip. I'd much prefer it the other way around. It's a pain to pour water so slowly for 3 minutes and gives the phrase 'water torture' a whole new meaning. But it does give me time to talk to my customers about coffee. Along with the 130 or so cups I poured, I sold 30+ bags of coffee.

IIRC, fluid-bed, though, so the context is different. My point was that you are right in your context, just as he is right in his. I don't think that either is wrong; I hope to learn from others' experiences.

In any case, food for thought. My opinion is that results trump dogma. A rear-engined 911 is a great sports car, even though top sports racecars are exclusively mid-engined (where rules allow).

What a good read. Thank you baldheadracing