I'm still working on a graphic to make this thing more understandable. The previous chart was waaaaay too complicated. Here's the latest stripped-down version. Note that the ratios for ristretto, regular espresso, etc aren't requirements, or even guidelines. They're just observations about how people pull and name their shots.

You already know I am totally into this idea.

My next set of tests (when I am hiding from competition practise) will be something along the lines of how brew time starts to affect the whole thing. Using one blend and one brewing style, keep the volume consistent and the dry weight fairly constant and see what happens with different brewing times.

I am looking forward to the first roaster suggesting you dose 19g, brew at 202F and in 27 seconds pull 30g of espresso.....

King Seven wrote:I am looking forward to the first roaster suggesting you dose 19g, brew at 202F and in 27 seconds pull 30g of espresso.....

Would that (19g) recommendation be for a specific machine? There are so many types of espresso machines out there, perhaps just a recommended brewing ratio would be more useful?

Henry

AndyS wrote:I'm still working on a graphic to make this thing more understandable. The previous chart was waaaaay too complicated.

How about a stacked bar chart along the following lines?




Or a curve showing degrees of variation within each type:




Regards
Timo

King Seven wrote:My next set of tests (when I am hiding from competition practise) will be something along the lines of how brew time starts to affect the whole thing. Using one blend and one brewing style, keep the volume consistent and the dry weight fairly constant and see what happens with different brewing times.

Excellent

King Seven wrote:I am looking forward to the first roaster suggesting you dose 19g, brew at 202F and in 27 seconds pull 30g of espresso.....

..."in a LM ridged double basket."

In addition to the basket, since different machines provide differing amounts of head space above the basket rim, that too is a factor.....

I like your ideas, Timo, although I'm lousy at the graphics stuff. I would love to do something like your second graph, but instead of lines dividing ristretto from normale from lungo, I'd have a color gradient that smoothly went from one to the next.

AndyS wrote:I like your ideas, Timo, although I'm lousy at the graphics stuff. I would love to do something like your second graph, but instead of lines dividing ristretto from normale from lungo, I'd have a color gradient that smoothly went from one to the next.

The gradient would be nice, it would suggest a continuum rather than discrete borders. You can see that a loose ristretto is rather like a tight normale, at least in terms of the ratio of bean to beverage produced. I am sure there are graphics tools that could produce the effect you like, though I don't think any of the charting tools I have access to will produce a gradient effect left-to-right below the curve. The grid lines can be hidden, though, fairly easily.

Regards
Timo

Turns out Excel has a gradient fill feature. Sorry about the less-than-tasty beverage color.
From tight ristretto to lungo+.

timo888 wrote:Turns out Excel has a gradient fill feature. Sorry about the less-than-tasty beverage color.
From tight ristretto to lungo+.

That is very cool, thanks Timo.

I was messing around with this yesterday.

Decided I would do a little experiment where I kept the basket, grind and brew time constant (stuck it at 25s) and then vary my dose to see how things would change. As expected the higher the dose, the higher the brew ratio but what I didn't expect to see was a kind of choke point where suddenly you crossed over a certain dose threshold and the flow becomes dramatically slower. I didn't really do enough shots to have enough data to post anything, and it may not even be a worthwhile experiment but it has left me a little curious.

King Seven wrote:I didn't expect to see was a kind of choke point where suddenly you crossed over a certain dose threshold and the flow becomes dramatically slower.

Hi James,

The choke point thing is very interesting. One question that always comes up in my mind with this stuff is how does your preinfusion affect the situation? In my experience the degree of preinfusion (or lack of it) is crucial to the flow characteristics. And when you run the experiments, you want to make sure the preinfusion is consistent, which is not that easy to do when the dose changes a lot.

King Seven wrote:I was messing around with this yesterday.

Decided I would do a little experiment where I kept the basket, grind and brew time constant (stuck it at 25s) and then vary my dose to see how things would change. As expected the higher the dose, the higher the brew ratio but what I didn't expect to see was a kind of choke point where suddenly you crossed over a certain dose threshold and the flow becomes dramatically slower. I didn't really do enough shots to have enough data to post anything, and it may not even be a worthwhile experiment but it has left me a little curious.

The Illys (Book of Coffee, p. 183) give a bar chart showing flow rate at five-second intervals for a proper extraction. The flow increases for the first 15 seconds then decreases in the latter half of the shot. Here's the same data with a line chart:



With respect to the "choke point" -- are you saying that at some point a fractional increase in dose results in a shot that never begins to flow, or in a shot that stalls midway somewhere?

Regards
Timo

This is what I mean. There is a very sharp, sudden increase in the brew ratio corresponding to a massive decrease in flow speed. You would expect a straighter line for the last couple of results.

I need to do a lot more shots - the data pool is really far, far too small to be significant.

King Seven wrote:This is what I mean. There is a very sharp, sudden increase in the brew ratio corresponding to a massive decrease in flow speed. You would expect a straighter line for the last couple of results.

I need to do a lot more shots - the data pool is really far, far too small to be significant.

Just to make sure we are on the same page, by "increase in brew ratio" I take it you mean a decrease in beverage produced relative to the dose, in the constant allotted time.

It looks as though at just above the 15g dose, the amount of beverage produced in the allotted time drops precipitously. Your graph might be easier to understand if the Y-axis represented a simple value, i.e. the beverage grams produced, rather than a complex value, i.e. dose grams divided by beverage grams.

This phenomenon could be explained by the puck needing to expand from the hydrostatic pressure but having no room in which to do so. This lack of space would cause the cake to wedge very tightly into available space, the grains swelling into each other, with the net result being that the cake is no longer sufficiently porous to allow water flow through it. What is your headroom at 15g?

Regards
Timo

P.S. I can get 10g into a 49mm single basket. What double basket are you using that 15g would be such an overdose? Are you sure your dose measurements are accurate?

Sorry - forgot to say I was using a single basket! Apologies....

King Seven wrote:Sorry - forgot to say I was using a single basket! Apologies....

Well, that would explain it. 15g in a single basket, and very likely you are running out of room in which the puck can expand under hydrostatic pressure. (Illy devotes many interesting pages to this phenomenon.) Inability to expand chokes the flow.

Regards
Timo

I am still playing with this concept, recording weights and calculating brew ratios for some of my daily shots. By doing this I have done of few things to improve my barista techniques, improve my results and explore new taste profiles.

First off, once I realized that I was rather consistently packing in 20g in a 14g "LM" ridgeless, I took some steps to reduce that a bit. I have tightened up my grind a bit, decreased my heap size, experimented with a two-finger Stockfleths-like move, and reduced any motion of the portafilter to just one or two twists while in the doser forks (I was moving it a bit more before, but not tapping the forks). Well, with two different grinders, I am consistently finding my dose to be ~18g now. To dose any less than that, I would to have to resort to some "leveling less than the basket rim" technique. For now, I really didn't want to go there again (I've been there and I think it is very difficult to be consistent). I am avoiding the shower screen screw on lock in now, and looking at the spent puck, I might have *just* a liitle bit too much coffee in there. Over time, I will try to reduce the dose a bit, and/or play with different baskets.

Second, I took the opportunity to explore a diifferent brew ratio space, changing my drinks from my typical 45-50% brew ratio, on up to the 75-85% brew ratio, or 21-24g beverage weight. I wanted to see what I might be missing, and I have been missing something indeed. While I enjoyed my shots before, and I don't think I was overextracting much if at all before, this is a much different experience, and has brought me much more satisfaction with my straight shots from Silvia.

BTW - James, 15g in a single, wow! This is a 53mm La Spaz?

jesawdy wrote:I am still playing with this concept, recording weights and calculating brew ratios for some of my daily shots. By doing this I have done of few things to improve my barista techniques, improve my results and explore new taste profiles.

Hi Jeff:

It's cool that you really "get it."

The brewing ratio concept in itself does nothing to improve your shotmaking (only your own experimentation and tasting can do that).

But the brewing ratios help us to organize our experimentation and help us communicate what we're doing to others. From your description, I know pretty much what you were playing with, and I can duplicate it pretty accurately with my equipment and my coffee.

Regards,

Thanks to all who have participated in this thread... I thought I was a bit over the top when it came to having a powder scale in my kitchen, carefully weighing doses per basket. But this thread has shown me the additional peice of the puzzle which is the weight of water used in each extraction. I time my extractions and keep each one consistent and but actual weight of the extraction? Now I have an additional piece of critical data for input. Thanks for the charts and tables they are great...

Sorry for being late to the party But I needed just to learn a bunch before I got into this depth.

(LOVE Geeking out with numbers and gear)

My Background:
Machine: QuickMill Anita
Grinder: MACAP M4 Stepless w/ doser
Coffee: Black Cat roasted on 1/24/07
Scale: .1g accuracy, calibrated with a 200g weight(300g max rating)

My Anita is my first REAL machine (Had S* barista for close to 10 years before anita). Had Anita for about 6 weeks now and just starting to pull consistent decent shots. I think I was over dosing?

My Method:
-Weight empty dixie cup and zero scale (tare).
-Dose into dixie cup and weight till desired dose.
-Weight dry espresso cup.
-Flush Anita with PF in place.
-Dry PF and pour ground coffee into PF, WDT, Tamp and polish
-Lock PF in and pull into espresso cup.
-Weight espresso cup with espresso.

Here are my results from this morning:

Dry coffee: 14.5g
Espresso: 30.4g
Brew Ratio: 48%
Shot Volume (incl Crema): 35ml
Total Shot duration: 24 seconds (including about 6 seconds for drops to form on bottom of PF).

There was some blonding right at the end of the shot, but overall the taste was pretty good, one of my average pulls.

Shot volume was low right? but the BR indicates about a standard double right?

What do you guys think?
-Craig