Announcement

Collapse
No announcement yet.

Grinding a single dose Vs using a full hopper

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Those who add beans on demand to the hopper, where do you store your beans and what volume of roasted beans do you keep on hand at any one time?

    I assume most keep the beans in an airtight container in a dark place and you keep a maximum of 250 grams on hand? Has anyone got any idea what the decrease in bean life/flavour would be if you had a small hopper with lid (say to hold 300gms) and you painted it black. That way the darkness is covered and although a hopper on the grinder would not be totally air tight there is not going to be a lot of air movement through it. I ask as I have just bought a Gino Rossi CC45 and was wondering if storing my freshly roated 250grms of beans in this manner was a viable option. It seems it may be given the evidence above about the benefit of some bean weight in the hopper?

    Comment


    • #47
      Nope. They will stale early if left in the hopper. Air movement has little impact I suspect.

      I only put the beans I plan to use immediately, in the hopper. Any that have been there for half an hour or so I will purge (overkill, maybe).

      Generally have 250g or so on hand, usually <2 wks post roast.

      Comment


      • #48
        Originally posted by MrJack View Post
        Nope. They will stale early if left in the hopper. Air movement has little impact I suspect.
        OK so what is it that makes them stale early, light? How do you store your 250 grms to minimise them going stale?

        If air movement has little effect on them I am trying to work out why beans in a blacked out hopper kept at a constant temp would not stay as fresh as long as beans stored how people usually store them?

        Comment


        • #49
          Originally posted by Burnsy View Post
          OK so what is it that makes them stale early, light? How do you store your 250 grms to minimise them going stale?

          If air movement has little effect on them I am trying to work out why beans in a blacked out hopper kept at a constant temp would not stay as fresh as long as beans stored how people usually store them?
          Most people here (I think) store their beans in ziplock bags with one way valves, so that the amount of air that the beans come into contact with is reduced greatly. These are then stored in a cool dark place. Your blacked out hopper idea, while understandable, will a) expose the beans to quite a lot more air , and b) likely expose the beans to variation in temperature (for starters....grinders generate heat). Anyway, it's a red door that you're supposed to paint black, not a hopper

          Comment


          • #50
            Originally posted by MrJack View Post
            Nope. They will stale early if left in the hopper.

            Any that have been there for half an hour or so I will purge (overkill, maybe).
            Whole beans don't go stale in half an hour.

            This is certainly overkill, as Mr Jack admits. Don't become confused or paranoid by taking this MO this as essential.
            Even tho' I'm up to my neck in roasted beans I couldn't be so wasteful.........but we all have our own way of doing things; so each to their own.

            (I do purge the grind path tho' and would if the delay between grinding shots was over a minute or so).


            Originally posted by Burnsy View Post
            OK so what is it that makes them stale early, light? How do you store your 250 grms to minimise them going stale?

            It's oxygen that makes the beans stale, Burnsy. Even storing them in a ziplock bag won't prevent the oxidation process, which started with the roasting of the beans.
            Hence the generally accepted 3 week window for fresh roasts.

            Light and higher temps play a part as well but O2 is the big culprit; affecting a group of volatile and reactive compounds.
            Your hopper isn't airtight.

            Degassing of CO2 causes oil migration to the surface of the bean which is also exposed to accelerated oxidation.
            The darker the roast, the easier the migration path and the faster the oxidation.

            Barry O'Speedwagon's advice re zip lock bags is the goods.

            Tupperware or airtight glass are also fine but leave some headroom for degassing.

            Comment


            • #51
              Thanks, all makes sense.

              Comment


              • #52
                Originally posted by Burnsy View Post
                OK so what is it that makes them stale early, light? How do you store your 250 grms to minimise them going stale?

                If air movement has little effect on them I am trying to work out why beans in a blacked out hopper kept at a constant temp would not stay as fresh as long as beans stored how people usually store them?
                G'day Burnsy

                The four "whole bean enemies" are heat, light, moisture and airflow (almost certainly not in that order). Too much airflow and the beans would be unlikely to last a day. Don't just take my word for it, try it! Leave them "in the open" on a dry, cool, dark, large surface (say in a large cupboard) and see how good they are after a few hours. Later, when you first open the door, you can smell the best portion of the beans in the air. Then try to drink the resulting cuppa. Or perhaps not all of it... one sip is enough.

                The grinder's other main issue is the need for the weight of the beans to feed the mechanism properly. Lack of weight = crap particle size spread for over 90% of home / smaller commercial grinders anyway. Simple example: a Mazzer SJ (I know four of them quite well) needs at least 250g to feed the maw properly when all is clean and calibrated. Less than that introduces bitterness inversely related to the bean weight. From very good spread to a sink job in one easy ignorant step. How many times have you been at a "good-ish" cafe, heard the grinder race and promptly received a sink job? Not a coincidence.

                If you have a fairly vertical hopper (i.e. like a SB EM480) it is easy to add a "precise fitting internal sliding lid" (a slightly tapered, weighted plug?) which does two things:-
                1) adds weight above the beans so the grinder mechanism works properly until the last gasp (or at least until the hopper narrows too much). In an EM480, that is around 50g of "tail end" beans.
                2) Reduces the bean's airflow to negligible amounts.

                If you have a more funnel shaped hopper (i.e. like most hoppers, unfortunately, including my Vario and RR45), you can come close with a weighted plug and a flexible seal. I am lucky enough to have access to a whole pile of medical grade stuff for things like that. Chemistry lab / science equipment shops may have similar items?

                Adding a properly fitting "top lid" and controlling the environment a little removes the moisture and heat. A darkish hopper covered by something as simple as a tea towel can remove the light unless it is in actual use. Alternatively, you can go as fancy / hi tech or low tech as you like. Even a bird cage hood works (seen it at a fellow coffee fiend's place).

                Tea towel: Works for me, got to keep it somewhere handy... (FYI: dry stuff only, not wet).

                Hope this helps


                TampIt

                Comment


                • #53
                  wrt commercial grinders.

                  What may or may not be pertinent for a mazzer type grinder with its particuclar adjustment design shouldn’t be generalized to cover all types of grinders especially those that have a regular threaded adjuster.

                  In which case the first principle to understand, is that no matter how well designed, machined and built a grinder is, there will be some element of end float in the adjustment, no matter how small, if there is no (or not enough) coffee in the grinding chamber.

                  A full charge of coffee IN the grinding chamber during the grinding process, has the effect of positioning the grinding plates to the end of their possible end float during grinding.

                  The idea is to always have coffee beans in the hopper so the feed into the grinding chamber is always at its maximum. That doesn’t mean the beans in the hopper need to be a certain minimum volume or weight OR that they need to be weighted down, it just means there should always be enough beans in the hopper to facilitate a full feed into the grinding chamber, which together with the forces generated by the motor, will position the plates at the end of their possible end float and result in an even grind.

                  That can be as little as just enough beans to fill the inlet throat (top plate mount, very bottom sleeve of hopper), for those that only grind enough for 1 or 2 cups, as long as for each session, the quantity of beans is replenished and....

                  ...what it all means is that operators should not grind out all the beans and use the resulting grinds to make their coffee, because that is where there will be inconsistencies in the grind.

                  Comment


                  • #54
                    One quick question about all of this...

                    As beans, particularly fresh ones, degas they release CO2- a lot more in the first few days than later on, but still... As CO2 is heavier than air (and O2), wouldn't this form a protective layer of sorts over the beans in a hopper? I can't imagine the convection currents in a hopper indoors with its lid on would be that significant? Or is there not really that much CO2 given off by the beans- can someone shed some light?

                    Remi

                    Comment


                    • #55
                      Originally posted by remi View Post
                      One quick question about all of this...

                      As beans, particularly fresh ones, degas they release CO2- a lot more in the first few days than later on, but still... As CO2 is heavier than air (and O2), wouldn't this form a protective layer of sorts over the beans in a hopper? I can't imagine the convection currents in a hopper indoors with its lid on would be that significant? Or is there not really that much CO2 given off by the beans- can someone shed some light?

                      Remi
                      10/10 for coming up with a fantastic theory, a protective layer of CO2 stopping oxygen from touching the beans. But you're not considering the CO2 falling through the beans and out the bottom of the grinder. Other than that, I like your thinking!

                      Comment


                      • #56
                        Maybe a rubber stopper pushed into the burr chamber discharge to stop the CO2 escaping?

                        Comment


                        • #57
                          ORRRR, you could put the grinder with hopper full of beans into a large plastic bag and seal the top, nahhh, don't think so.

                          Sorry guys this thread has started to get seriously weird.

                          Comment


                          • #58
                            Using a CO2 fire extinguisher you could always give the beans in the hopper a spray every once in a while to keep the CO2 levels topped up

                            Comment


                            • #59
                              Just put some dry ice in there - slow release

                              Comment


                              • #60
                                Originally posted by Yelta View Post
                                ORRRR, you could put the grinder with hopper full of beans into a large plastic bag and seal the top, nahhh, don't think so.

                                Sorry guys this thread has started to get seriously weird.
                                Not that weird really- co2 is commonly used in several industries to keep food products fresh.

                                I don't see how closing up the bottom of the hopper/ grinder and giving a squirt of co2 into the hopper is that much more complicated than some of the ritualised acrobatics described so far in this thread...

                                Remi

                                Comment

                                Working...
                                X