Here's my check list every time I go to one of our stores I go through this whole list. I'll throw in some of my personal notes as well to help you guys out.
I. Equipment Check
Is the batch brewer level? Main points to check are the spray head and bottom of the filter basket. I use a bubble level app on my phone since it's easier then carrying a bubble levle with me
Is the brewer spraying out hot enough coffee and is the saturated bed staying hot enough? We have a special filter basket that has a probe that we use to check the temperature in the basket during the brew. Ideally you want your water at 200-202 and the bed 195-200. If your bed isn't staying hot enough, you might have to wrap your basket in some insulating tape such as the type used on car exhaust.
C. Water Quality
Does the water fall within our recommended PPM for our coffee. Double check mineral content by isolating magnesium, calcium, bicarbonate with a titration kit.
D. Grinder Burrs
Are the burrs in good condition? Visual inspection and double check using a sieve stack.
E. Bed Depth
Ideally we want something between 2.5 and 5 cm in bed depth. Easiest way I found to do this is to use a post-in note. Embed the sticky note into the dry bed after grinding with the stick side perpendicular to the ground. The grinds will stick to the sticky part of the note. Length of grinds on the sticky side of the note = depth of bed.
A. Batch size
Are the batches small enough that the coffee is staying less than an hour old?
Can we make batch sizes small enough that we can maintain freshness without having a bed depth that is too shallow? If we can't, advise on smaller brewer or alternative basket. Batch size should satisfy both coffee <1hr old and bed depth >2.5cm
B. Extraction % and Strength
What's our brew ratio? Aim for 1:15-1:18 for lighter roasted coffees, 1:17-1:19 for darker roasted coffees. Shoot for 19-21% EXT and 1.15-1.4 TDS (depending on flavor)
If possible, program a pre-wet cycle on the brew equal to 2ml per gram of coffee (11-13% of the brew volume). This useful for moistening all areas of the bed & drives off some CO2 which tames the bloom. Pre-wet should have a 30-60second delay, bigger batches/deeper beds need a longer delay (45-60 seconds) to allow water to filter through the whole bed of coffee
D. Brew Time
Aim for a brew time between 5 and 6.5 minutes. Brew time is total programmed time + time until brew starts dripping from the basket. Larger batches should have shorter programmed brew times (4min) to as water takes longer to filter through. The longer it takes to filter through the bed, the longer the coffee will come out from basket after brewing is done.
Although I'm not a believer in puckology, I think examining the bed of grinds can be quite useful. A perfectly flat bed indicates even extraction during the draw down. Excess grounds stuck to the sides of the filter is not good. Grinds stuck to the side will be underextracted in relation to the grinds in the bed. If grinds are stuck to the side, extend brew time. If you are already at the limit of 6.5min for brew time, coarsen your grind then re-adjust dose and yield to maintain TDS and EXT% target