The two tools that we'll be reviewing today is:
One Eight Zero Leveller by Artisan Smith
The One-Eight-Zero Leveller is adjustable in depth just like the OCD is. We were recommended to use it with the leveller adjusted to be as deep into the portafilter basket as possible. We will be testing it with the setting at both the shallowest depth and the deepest possible depth.
Twister Distribution Tool by EdoBarista:
Disclaimer : We are by no means statistical / math / science experts. This is just a simple experiment carried out to give us an idea of the performance of each method only. People are more than welcome to give their feedback on how we can improve and carry out a more academically approved experiment / report.
Since the previous experiment has concluded the original stockfleth finger distribution method to be the winner, we will go along with the same theme for this round and state the hypothesis as:
The stockfleth finger distribution method will result in a higher and more consistent coffee extraction.
Uganda Sipi Falls, Organic Certified
Process : Fully Washed
Variety: SL14 & SL28
Roast Age: 18 days from roast date
Agtron : 60 (Whole Bean), 70(Ground)
Grinder : Nuova Simonelli Mythos One Climapro Grinder
Distribution Technique : Stockfleth Method
Tamper : PergTamp 58.5mm diameter
Portafilter Basket : VST 18g
Espresso Machine : Slayer V3
Brew Pressure : Full Brew Pressure at 7 Bars / Measured using Scace II
Brew Temperature : (Controlled Variable / Initial calibration at 93.3C)
Grouphead Flow Rate : 117g water / 10s ( Full Brew Pressure ), 28g water / 10s (Pre-infusion Brew Pressure set to maximum 3 bar)
Coffee Refractometer : VST Coffee III
Calibration : *Optimal Calibration is set at the furthest possible point in extraction whereby minimal to zero astringency/bitterness is detected in the cup and sweetness is at its maximum.
Dose Tolerance : 18g
Shot Tolerance : 40.0g ± 0.5g
Step 1: Calibrate coffee using stockfleth distribution method.
Step 2: Pull 10 shots with the same calibration using One-Eight-Zero Leveller (shallowest depth setting).
Step 3: Pull 10 shots with the same calibration using One-Eight-Zero Leveller (deepest depth setting).
Step 4: Pull 10 shots with the same calibration using Twister Distribution Tool.
Step 5: Allow espressos to cool before measuring Total Dissolved Solids (TDS%) and Extraction percentages.
Looking at the results above, almost every method had a statistically significant difference compared to the original stockfleth method. There are a couple of observations we have made here:
1. The stockfleth method results in a significantly higher average extraction percentage.
2. The distribution tools does seem to provide smaller variances in extraction range (after accounting for the outliers). This means they are possibly more consistent in their results.
3. During the experiment, we tasted the shots from all four distribution tools, using shots from the stockfleth as the control. The shots pulled from the other three methods all had a perceptible bitterness in the finish. Particularly the One-Eight-Zero with the deepest setting and the Twister tool.
So the results do help to support our original hypothesis :
"The stockfleth finger distribution method will result in a higher and more consistent coffee extraction."
In comparison to the OCD tool from round 1 of the experiment which had both lower extraction percentages and higher variance, the One-Eight-Zero seems to provide a slightly better solution to distribution due to its better consistency in results. The only catch is to use it at the most shallow setting as possible. Also the additional bitterness that presented itself in the shots might mean that a shorter yield or slightly coarser grind might be necessary when using this distribution tool.
However, if higher extractions are your thing, you might be better off learning and mastering the stockfleth method of distribution. There can be higher inconsistency and variance with this method, especially from barista-to-barista, but the benefits of a better tasting espresso shot is definitely there. The choice is yours.
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