http://www.prufrockcoffee.com/the-iq-gr ... ng-london/" onclick="window.open(this.href);return false;The IQ Grader - An exam to plot yourself on the smart vs best continuum. Some questions have more than one answer, some have none. Answers next post.
1. A coffee is pulling at 18.5%. You score it at 2.5s (on the WBC score sheet: average-good). You’re dosing 18-34g and the timer says 28 seconds. There is some astringency in the shot and it is imbalanced towards bitterness and light bodied. Your brew water is 94degc.
Do you?
a.) drop the dose and grind finer
b.) decrease the brew water temp
c.) coarsen the grind and increase the brew water volume
d.) consider changing the grinder blades
2. You shot tastes sour and thin bodied.
Do you?
a.) increase the dose and grind finer
b.) decrease the dose and grind finer
c.) keep the dose the same and grind finer
d.) keep the dose the same and grind coarser
3. Your shot reads 20.5% extraction yield and you’ve pulled an 18-38g brew ratio in 30 seconds. You find some sweetness but there is some mild astringency.
Do you?
a.) fine the grind and reduce the dose
b.) coarsen the grind.
c.) coarsen the grind and reduce the yield.
d.) get yourself a new Linea PB
4. You taste bitterness and astringency on a 20-40g brew ratio and a 36 second shot time
Could this be caused by?
a.) over-extraction
b.) under-extraction
c.) channelling
d.) excessive tamp pressure
5. In your cafe you use the WBC scoring system to maintain quality. You’ve pulled five shots scoring only 3s in each category of the WBC scoresheet and the coffee has been tasting light bodied and sour the whole time with shots falling between 20 and 30 seconds.
Should you?
a.) accept the scoring ceiling has been reached for this coffee and remove this coffee from service.
b.) fine the grind and explore shot times between 30-40 seconds
c.) increase the water temperature.
d.) b and c.
6. You’re pulling shots that all taste sour and you are on a 40second shot time and a fine grind. You are on a 50% ebf and yet they still taste sour. There is not bitterness or astringency in the cup and you know the coffee is a good coffee from a reputable roaster and makes a lovely filter.
What will most immediately reduce sourness?
a.) increase water temperature
b.) drop the dose and pull the shot longer
c.) grind finer still
d.) increase pre-infusion
7. Preinfusion helps increase extraction because
a.) it allows you to grind finer
b.) it reduces fines in the cup
c.) it increases overall brewing temperature
d.) it increases flow rate
8. Your are getting excessive channelling.
Would this be most likely be cause by?
a.) your tamper being slightly convex
b.) the way you insert the portafilter into the group
c.) flow restrictors being too small
d.) overdosing the filter basket
9. You are pulling big split triples at 24-55g. You detect over-extraction.
Would it be most efficient to?
a.) drop the dose and grind finer
b.) increase the dose
c.) decrease the beverage size
d.) coarsen the grind
10. You detect over-extraction in a brew
Would the most likely reason for this be?
a.) one of the ingredients in your blend is lower density
b.) one of the ingredients in the blend is castillo variety
c.) the water you are brewing with has dropped in TDS to 50ppm
d.) your roaster has just employed a new head roaster
11. You are scoring what you think is a 3.5 out of 6 on the WBC sensory score sheet but you sense there’s a 4 there just around the corner.
Should you?
a.) just serve it
b.) ask the customer if they’d like you to serve this one or if they want to wait a second while you tighten up the grind
c.) nutate a little more
d.) remove quakers from the hopper and winnow out the chaff from the centre cut
12. Your company has established a scoring minimum of 3.5 in all categories on the WBC sensory score sheet and they expect you to hit this target in 4 shots. You have pulled 4 shots during dialling in and none of them have hit the 3.5 you’re after.
Do you?
a.) kept pulling shots on different recipes until you hit the god shot shot you always knew was there
b.) just serve it
c.) take the head barista aside and suggest the current blend might be hitting a ceiling below your quality threshold so they better contact the roastery to negotiate a better coffee for the next order
d.) send this coffee back and ask for a refund
13. Your coffee tastes a tiny bit roastier than the previous batch from last week.
Do you?
a.) pull the shots longer
b.) pull the shots a touch shorter and reduce extraction and increase brew strength
c.) increase the dose and grind finer
d.) decrease the dose and grind finer
14. The best coffee equipment is that which
a.) achieves the highest extraction on a given shot time
b.) slows down the rate of extraction
c.) has the lowest astringency ceiling
d.) is the most temperature stable
15. The best grinder burrs are those that
a.) reduce fines production
b.) reduce boulders
c.) increase sweetness
d.) have a higher astringency ceiling
16. The best grinder is
a.) the easiest to clean
b.) the most ergonomic
c.) that which maintains a stable shot time and dose
d.) all of the above
17. The best barista
a.) does the dishes and smiles at the customers
b.) tastes the most
c.) needs to make the fewest changes to the grinder
d.) makes the most changes to the grinder
18. The best dosing and tamping technique achieves the
a.) lowest extraction over a given shot time
b.) achieves the highest extraction over a given shot time
c.) achieves the lowest flow rates at the highest pump pressure
d.) distributes the coffee the fastest.
19. The best roasted coffee
a.) gives the broadest extraction and shot time range for balanced shots
b.) tastes the most full bodied
c.) extracts the most easily
d.) tastes the most balanced
20. The best espresso machine
a.) dispenses the most stable water temperature
b.) is the easiest to service
c.) is low profile so you can see the customers; is ergonomic and looks fantastic
d.) is under counter
21. An espresso is balanced when
a.) it has no bitterness
b.) there is an harmonious balance of sweetness, acidity and/or bitterness
c.) it is the sweetest
d.) when it is 18-22% extraction
22. The best tamper
a.) has a ripple base
b.) allows for the best pre-infusion
c.) reduces channelling
d.) promotes the highest extraction yield
23. Your grinder burrs probably need replacing
a.) every 250kg
b.) when the grinder starts heating up above 45degrees during busy periods
c.) when you taste flavours associated with over extraction when your average extraction yield is under extracted
d.) when the grinder takes more than 3.5 seconds to produce 18g of grinds
24. You coffee tastes sour. Is your water likely to be?
a.) too high in calcium
b.) too high in KH
c.) too low in sodium
d.) too low in KH
25. Brewing at 11 bars of pressure will?
a.) increase flow rates
b.) permit me to grind coarser
c.) reduce espresso beverage size
d.) Increase channelling
26. Hotter grinds during busy periods will?
a.) decrease extraction
b.) increase extraction
c.) increase aromatic intensity
d.) increase astringency
27. The best distribution of coffee grinds is
a.) the method that promotes the fastest flow rate
b.) the method that moves coffee equally into the north, south, east and west of the basket
c.) the weiss distribution technique
d.) the method that promotes the highest extraction yield
