Why the "golden rule" of time/volume should be bent

[TimEggers]

It is conventional thinking that "...a double is a 1.2 to 2 ounce espresso made from 12 to 20 grams of coffee. Singles and doubles take the same amount of time to pull, roughly 25 to 33 seconds" are the best guidelines of the extraction. I concur it is a great starting goal from which one can wander from to see what works best for them and/or their machine.

In the spirit of experimentation I began to experiment with my new Anita and her brewing pressures. I am currently at 8 bars (a little low compared to the typical accepted brewing range of 8.5 bar to 10 bar, but this is subjective). I have blatantly defied the suggested brewing methodology and have come up with exceptional results:



Watching this video you will see that the extraction is very long. The resulting volume is a little low but still acceptable. I stopped the extraction just as the stream began to blonde. I didn't know what to expect as far as flavor or body, but when I sampled the shot I was knocked over. It was the best thing I've had for a long time. Why? The body was smooth and heavy with no grit to it at all. The flavor was a nice pronounced chocolate with a subtle hint of blackberry. Very nice complexity and a long pleasant aftertaste simply a beautiful double shot, and definitely one of my best. But could I do it again? Yes, the video above is my second double shot. The bitters and sours were balanced and the shot had a nice sweetness. Clarity was also nice. In short a beautiful shot.

My point in all this to encourage experimentation (but only after you achieve consistency and understand espresso). Here I am breaking most every established "rule" and yet I'm making some of the finest shots that I ever have. It should also be noted that established practices offer an excellent starting point, but don't accept them as law, rules are meant to broken!

[oofnik]

rules are meant to broken!

I'm glad I'm not the only one who thinks like this. It's a very true statement whether you're talking about espresso or any sort of hobby with a common wisdom associated with it. How else would anything new be developed if people didn't try different things?
It's about time someone brought forth a new school of thought to the espresso world. Playing with the numbers and throwing the 'right' ratios way off and still getting excellent results is a sign of someone who truly knows what is going on here. Awesome work.

I'd be interested in knowing all of your parameters exactly. Blend, grind, dose, tamp, temperature, basket, etc. Man we have a lot to worry about, don't we.

[HB]

Yikes, a sixty second super tight ristretto. That's 18 seconds past the point I would declare it fissile material. I'm surprised it was drinkable! I knew ristretto pours break the golden rule, but they break it even more with low brew pressures? The very opposite recommendation of Jon's ristretto tweaks... interesting.

[jesawdy]

Ha! Well, if you use Jim's rule of timing the shot from the first drops, you were at about 30 seconds.

What sort of brew ratio are you finishing at? (Do you have a scale?)

EDIT - My second thought is that you may be somewhat approximating the lever experience.... a long preinfuse, lower pressures and smaller volumes.

[starry]

Wow Tim! I couldn't agree with you more. I recently got some of the coffee that Abe Carmeli recommended and had a tough time with it. I simply could not get anywhere near the results that should be expected from a coffee of that stature and wondered why. After reading about your experience, I thought why not at least try it so I took your advice and pulled the shot on my Cremina 67 with less pressure than I have been using routinely (and getting great results with other coffees). Voila! Every bit as good as Abe's description! Thanks!

However.....my OTHER coffee does not respond too favorably by lowering pressure or increasing shot timing.

[TimEggers]

I've been going over this all day in my head trying to figure out why I got the results I did. I think Jeff you are probably most right, I would guess (I'm not qualified to comment on lever pull flavor profiles) that I'm coming to close to replicating something along the lines of a lever pull.

Here is what I'm using:

Sweet Maria's Puro Scuro blend roasted to full city+ (First crack @ 15 minutes, few snaps of second @ 22 minutes) 2lb batch size; one of my slower roasts
14g dose by weight
35lb tamp per bathroom scale

The resulting cup was excellent. As I've said above the flavor was delicious as it had a sweet milk chocolate (no bitterness) and a dark fruited note. The flavor transition across the palate was nice to a smooth long chocolate aftertaste. The body was also very nice and what I liked best is that it was not grainy or gritty feeling rather it was smooth and creamy. The crema was a nice speckled rust color (no black tints at all); I was expecting an over extraction with these times. I can't say enough good things about the shots overall, they suited me well.

Now why in the world would a long pull like this make such a nice shot?

Here is where I'm stumped; my lack of knowledge and experience here really begins to show. If I had to speculate I would attribute the smoother body to fewer solids being passed to the cup via lower pressure. I would attribute the slow flow rate (flow of water through the puck) to the resistance of the tight grind and the lower brewing pressures (water not being pushed as hard against the puck).

Why I think my shot differs from a more traditional ristretto: I seem to be relying more on steeping the puck by using a lower pressure and far slower flow rate through the puck (hence the long brew time). This it appears offers the full flavor of the blend by means of water contact or "steeping" more so than pressure extraction (or forcing the chemical flavor components from the beans).

Thoughts?

[starry]

I'll take a stab at a theory: The bean has a physical structure. An analogy may be wood. Wood contains oils. Some of these oils are exposed when the wood is cut. The oils "wash off" somewhat easily from the surface. More oil could be extracted with pressure, but then the wood structure itself has other chemical compounds that come out with the oils. In the coffee bean, we may be extracting flavors within the structure of the bean that are distasteful when the brew pressure is too high?

[TimEggers]

I experimented today with trying a more traditional shot today. The shots were excellent with a lesser intensity but with the same flavors and same silky creamy body as those yesterday, truly exceptional espresso. I did take a video but it ended up being a little blurry so I won't post it but first drips came from spout at 19 seconds and the shot finished somewhere around 45 seconds. The finished volume was a little more than above. Basically came to be a toned down shot from yesterday.

I'm finding that I really like 8-bar. Probably because it's so gentle on my puck and is it appears more forgiving. I mean each shot is great. My success rate has gone up for sure with Anita. My Gaggia shots were good mind you, but with Anita I can get the lower pressures and in turn produce less intense more subtle espresso while keeping intact the flavors and attributes sought out. Something I am coming to truly enjoy. I'm getting the flavors, complexity and body without the harshish (is that even a word? ) intense overbearing punch.

It's ok to like subtle espresso right?

[Beezer]

It's funny that you bring this issue up. I find I've been letting my shots run longer since I got my Anita too. However, I did a shot yesterday that run really slow like the one you're talking about, and it tasted bitter and overextracted. It was so bad that you could taste the bitterness even with milk, and even my wife (who's not normally very picky about such things) noticed the difference. I do have my brew pressure set a bit higher (around 8.7 bar) so maybe that explains the different result. Still, most of my shots are running well over 30 seconds, and they taste pretty good to me.

[oofnik]

I think we're not placing enough emphasis on the actual differences between the beans. Since espresso is such a concentrated extraction by any standard, slight nuances in bean properties and chemical make up both as a result of growing and roasting play a very significant role in the end product, perhaps even more so than slight nuances in dose, pressure, and temperature. I would venture to say that a lot of us here have an experienced enough palate to be able to distinguish an Ethiopian Yirg from a Kenya, just as an example. However, we're also all pretty good at telling whether a shot was pulled too hot or too cold as well. But without really being familiar with a certain coffee, how would you know whether that stinging sour note was the result of too low a temp, or maybe your beans just aren't a suitable SO for espresso due to overpowering acidity? For those of you who like to experiment with SO coffees I'm sure you have come across something that, no matter what you do, just plain sucks as espresso. The only way to know is to experiment. We change our variables in an effort to best suit the properties of the bean, not vice versa. Of course, espresso blends aim to do the opposite: they are designed to be consumed as espresso, and as such are generally combinations of smoother, more well rounded coffees, and it's why we see a much higher percentage of Brazils in comparison to Panamas. I'm not a master espresso blending artist, so maybe someone who is would like to chime in on this one.

Basically, Tim, I'm trying to justify the difference between your results and Beezer's by saying that it's simply the result of using a different coffee. Some like to steep for a long time, allowing the richer, heavier flavors to slowly ooze out, while others like to wash off the oils quickly and not linger, or else nasty things start dissolving. I'm going to go out on a limb to say I believe there is an inverse relationship between brew time and bean density, i.e. as the density of a bean goes up, more time is required to extract the full flavors, whereas if that same amount of time was used for a less dense bean, all the flavors plus the nasties would end up in the cup. Of course, I have no data whatsoever to back that up. But it's a good guess, right?

Another idea that popped into my head: Perhaps your results have something to do with the concentration of dissolved CO2 in the water. CO2 readily dissolves in cold water and its solubility decreases as a function of temperature. CO2 decreases the pH of the water, making it more acidic. This alone changes the composition of the final solution (espresso) in relation to the chemical properties of the solvent (water + CO2) and the solute (coffee oils). However, solubility of CO2 is increased with respect to pressure, which is pretty much the reason (or one of them at least) why we get crema. By lowering your pressure, you are allowing less CO2 from the beans to dissolve in the water, affecting the entire extraction process. And maybe, possibly, less acidic water extracts less of the bitter compounds while allowing the flavorful oils to slowly seep into the water, which would explain why your super-long, low pressure shots are so delicious.

Well that's my $0.02. Interesting stuff to think about.

[AndyS]

If I had to speculate I would attribute the smoother body to fewer solids being passed to the cup via lower pressure. I would attribute the slow flow rate (flow of water through the puck) to the resistance of the tight grind and the lower brewing pressures (water not being pushed as hard against the puck).

Why I think my shot differs from a more traditional ristretto: I seem to be relying more on steeping the puck by using a lower pressure and far slower flow rate through the puck (hence the long brew time). This it appears offers the full flavor of the blend by means of water contact or "steeping" more so than pressure extraction (or forcing the chemical flavor components from the beans).

Thoughts?

[edited 4-13]

Hi Tim:

First, I wouldn't assume that your machine is now delivering a true 8 bar. Stock gauges just give an approximate reading; you would have to retrofit a precision calibrated pressure gauge in order to get a truly accurate read.

Second, for many reasons, the pressure your coffee experiences in the portafilter is quite different than the gauge reads. So without testing, it's very difficult for two people to compare brew pressure parameters unless they have a special means to measure pressure AT THE PORTAFILTER.

IOW, the oft-quoted 9 bar "standard" is really just a vague guideline.

Third, some sources say that a traditional ristretto IS brewed for a longer period of time than the usual 30 seconds.

Fourth, dropping the pressure from 8.5 bar to 8 bar will in theory have only a very small effect on extraction time. The traditional fluid-dynamics equation states that flow rate across a restriction is proportional to the square root of the pressure drop. The upshot is that going from 8.5 bar to 8 will increase extraction time less than one second out of thirty.

Fifth, it doesn't sound like you've confirmed that the pressure change is really what's making your current shots taste so good. If you tested to see if you can reliably distinguish espressos that were extracted at 8.5 and 8.0 bar in a blind tasting, it would be more significant. Otherwise, the good shots might to happening for another reason (the coffee has hit a sweet spot in its resting curve, etc).

[TimEggers]

Andy,

I agree with you here. I don't have the slightest idea why my long shots taste so good and I'll be the first to admit that. I am also going by Anita's gage (it's all I have for now) so even my pressure readings are ballpark at best.

I wanted to start this discussion because 1) that long shot was darn good and watching it pour told me it shouldn't have been and 2) I have no clue why that is.

You hit the nail on the head, I'm not offering any significant evidence of anything nor am I intending to offer concrete explanations for any results. I was only wanting to share what I was doing hoping that others here could chime in and help me to learn a thing or two (or maybe 1,000 but I digress) about making espresso.

Again I appreciate the comments, commentary and enlightenment from everyone. That's what it's all about!

[old442]

Tim,
I miss your old avatar. It just seem like you anymore

[TimEggers]

Tim,
I miss your old avatar. It just seem like you anymore

My little girl is growing fast, she's changed so much since that picture. Thought I'd go with something more up to date...

Edit- Yeah I miss my old one too, oh what the hey I grabbed the camera and took care of the situation! She's back...

[lblampman]

My little girl is growing fast, she's changed so much since that picture. Thought I'd go with something more up to date...

Edit- Yeah I miss my old one too, oh what the hey I grabbed the camera and took care of the situation! She's back...

Nice Tim! The latest photo of your daughter is the first thing I noticed this morning.

At this stage of her life you'll be changing your avatar pretty often if you want to keep up with her...lol...they grow oh so fast.

[Kaffee Bitte]

That pic still shows her with the wild over espressoed eyes though. I think it's fitting, just try to limit her caffeine intake a bit, OK?

[cannonfodder]

I have watched that video several times, and am still amazed that it did not taste like road tar. I have pulled some tight, slow ristrettos but nothing like that. I would have thought the extended extraction time would have made the cup very bitter and harsh from the massive amount of coffee solids and high temperature. That HX would have been getting pretty hot from that low flow rate.

[DC]

I have watched that video several times, and am still amazed that it did not taste like road tar. I have pulled some tight, slow ristrettos but nothing like that

I have to agree, nothing I've tried like that has been drinkable. I'm all for bending the rules but in my book that is a choked shot, and I'd grind coarser next time round. Of course, taste is very personal so if this is your preferred drink, then congrats on finding it!

[miKe mcKoffee]

Guess I'm strange but didn't find the reported results that odd at all. For quite some time when pulling ristrettos I've targeted 45 seconds with first drop expected in 12 to 13 seconds. That's with rotary not vibe, with vibe target would be more like 50 seconds and first drops around 20. While my time does include ~3 seconds lines pressure preinfusion, I'm running about 4bar line pressure and a normal will have first drop at lines pressure at around 6 seconds! Temp wise absolutely compensate for differing intrashot profile. With normal I can expect ~2.5f intrashot drop, with ristretto virtually dead flat to very slight rise. (As seen and measured with partially plugged Thermofilter and also now Eric's adapter) So I target start of shot temp about 1.5f lower for a long pulled ristretto compared to normal for same coffee.

My current shot blend has a Kenya component with great bright berry-wine notes. This puppy lets you know in a hurry if your temps are too high! Earlier today pulled a quite yummy 26 second 2oz shot start of shot temp target 200f. Just finished a 45 second 1oz ristretto pulled start of shot target 198.5f, zero bitterness and if anything sweeter than the normale. FWIW ristretto first drip right at 12 seconds including 3 seconds ~4bar lines pre-infusion before rotary presure slam. Oh, current no flow pressure set ~9.25bar. I do plan to mod' my PF mounted gauge adding fittings and needle valve so I can measure simulated shot flow pressures when I get it back from it's current road trip.

While I don't target 50 second plus ristrettos have accidentally pulled a few, usually without terrible results. But that's when already targeting a ristretto pull with corresponding lower start of shot temp. Way off grind intended for normale shot ending up super long ristretto most often pulled too hot with bitter result. (Like that way off 0.5oz in about 60 second pulled double of Light Full City WP Yirg' instead of sinking I actually tossed back last year, now that'll make your hair stand up straight!)

[miKe mcKoffee]

OTH accidentally ground at Rocky true zero instead of +5 so decided to try a lighter dosed very light tamp and go for it. (LM double basket) Well, approximately 1/2oz total volume (almost zero crema) later killed it at 60 seconds. Major sinker. Ground where I'd meant to be +5 and yielded a quite tasty 45 second 1oz crema laden double ristretto...