Coffee Laboratory

New coffee arriving at the start of next week for CCR. When it arrives we will update our offering list, which will appear as a new entry here.

This morning we added a new scale to our workshop, courtesy of A1-Scale on 23rd and Raleigh. They have a nice little showroom of scales. We like them because their business is mostly recalibration and refurbishing, and so they know what they sell from the inside out. We purchased an Ohaus Cent-O-Gram 311g balance scale, accurate to 100th of a gram (thats right, a hundreth!). This thing is totally sick, but please do not expect us to bike it to your establishment and weigh samples. Well, we totally would, but scales are pretty delicate.

This scale is a cool addition so that we may weigh very small amounts of coffee accurately. Last week Ray, formerly of Little Red Bike Cafe, came over and we had a discussion about stirring vs. no stir technique of french pressing coffee (we do not stir). We weighed out equal amounts of coffee and did two presses of coffee, lamenting the quality of our Soehnle kitchen scale (+/- 1 gram). Ray stirred, and we did not. Then we pressed, poured cups for ourselves, while straining a third cup out with a chemex paper filter, to check the amount of sediment in the cup. Ray’s stirring provided more fines in the cup (and more flavor!), while our no-stir made for a much cleaner cup, but without as much depth. Ray stirs gently, 40 seconds after the coffees contact with water, fine particles drop to the bottom. At the coffees pressing the absence of these fines allow more to move through the screen, any fine dust suspended makes its way through easier. I think we still have more to play with. We did have a small gram scale, but it did not like rechargeable batteries, nor could it be plugged into a power source with ease.

The scale is also precursor to a more interesting look of two commercial espresso grinders. Today we have shipping to us a custom Anfim Super Caimino grinder, altered to provide a lower burr rotation, with timer, with fan. We will be comparing this to the Robur 110v grinder w timer (both super nice commerical espresso grinders). Also we will be looking at the amount of grams we are dosing with our LSM espresso machine. For a short while we had a Robur with fractional second timer installed, however we never got close to using it with our LSM Leva machine. ..

9 Responses to “Coffee Laboratory”

  1. evan&ali says:

    do you push the plunger down so that all the grounds are under the water? this, to me, is a key step to a proper press but one that i feel is often overlooked. i like to do a brief 720 degree clockwise stir, and then plunge until all grounds are submerged, followed by a slow press. do you guys submerge the grounds using the plunger?

  2. dalas v says:

    Mark me down for stirring.

  3. joel says:

    We do not push the plunger down. We rest the plunger above the grounds. Either we pour fast, or we pour slow combined with swirling the press to wet the grounds. In both cases we wait a little before topping off a press with a thin pour of hot water, sinking anything floating above the water line. I guess sometimes we give a little swirl after the first pour and before the second. I would guess this leaves more of the fines floating at the surface, but less than if we actually stirred. We are lazy here and want to find the simplest way to make press coffee, using the least amount of tools, i.e. spoons. Much of the time we are washing the filter assembly while waiting to press. Having a head of grounds capping off a press insulates and also keeps the coffee grounds in the hottest of the water. Although its only too true that this becomes counter productive when the grounds are not in full contact with the water.

  4. miguel says:

    you’re really taking coffee production/consumption to new levels. i don’t think other roasters do things like this.

  5. John says:

    Quite a phenomenal scale. What’s it’s maximum weight? 311 grams? You remind me of Rose Levi Beranbaum. ‘At home I use the Mettler PE 16 electronic scale…accurate to within 0.2 grams. It weighs up to 16,000 grams. (35 pounds)’ That was in 1988.
    I have a little pocket cocaine scale, that I use for adding sulfites to wine. It’s accurate to a hundredth of a gram, but has a maximum weight of only 45 grams.

  6. joel says:

    yes. other roasters do this!! John, that sounds like a nice scale. A hundreth of a gram for a pocket scale? .001grams accuracy? 311grams is our scales maximum weight. But we got it to check things at around 16 grams. The guys at the scale shop told us it would outlast its digital brothers. Last night we used it to check doses with a new Anfim grinder that had arrived for testing. This grinder is currently at LittleRedBike and will be moving somewhere else later this week.

  7. AllanF says:

    Do you mean the “coarse” particles drop to the bottom, allowing the suspended fines to flow through the screen? This doesn’t make sense to me otherwise.

    Also, love the Ohaus scale. I used one in for all my high school science labs. My old high school probably had a few dozen of those things.

    Finally, 0.01 is a hundredth of a gram, so it would be +/-0.005g. 0.001 is a thousandth. If memory serves, at a thousandth of a gram (ie. +/-0.0005g), you have to start worrying about air currents. That level of precision will have a digital scale with a little glass enclosure over and around the sample pan. Of course, it’s been about 20 years and I can be mis-remembering and air currents might matter at hundredths of a gram.

  8. joel says:

    It measures a thousandth of a gram- correction (.001grams). It seems dust matters at this point, but our movement in the room does not. Letting the scale rest balanced with a calibrating weight over the course of the day, and a little dust will throw the scale off. Blowing it the scale goes back to correctly reading the weight. I do not have a clear memory of these scales from school.
    I feel like the “fine” particles drop. The course particles float. But there are super-fine particles that remain suspended. Or maybe the super fines drop and the fine particles are suspended.

  9. AllanF says:

    Thanks for the clarification. Interesting stuff!

    My memory on the air currents was the digital scale with the glass doors and enclosure had one more significant digit of precision than the balances. Also, as I think about it, there were two kinds of those Ohaus balances. There were 3 bar ones, which was standard throughout all my high school labs, and a “fancy” four bar one, that had an extra digit of precision that sat up on the teacher’s bench. Looking closely, seems you guys have the fancy 4 bar balance.