Looks can be deceiving: dialing in with the Sette burr

Posted on April 6, 2017 by Baratza in Blog, Burrs, Education, Grinders, Support

By Alex Choppin, Baratza Support Specialist & US Brewers Cup Competitor 2017

The Sette Series, with its revolutionary design and functionality, has really challenged our pre-suppositions as coffee professionals and grinder nerds. It’s an exciting experience for us, and from what our customers tell us, for them as well!

Here in Baratza Support, we’ve encountered a number of customers who struggle to grind coarse enough on the Sette for popular manual-brewing devices. Of course, we’re always quick to help resolve any component issues with a Baratza grinder that might lead to this kind of problem, but often we find that the machines are in good working order.

So what gives?

Of course, new technology can require new ways of thinking and operating, which is something we’ve seen with the Sette here at Baratza. So first, let’s have a quick refresher on burr grinders.

It’s important to start with the understanding that a burr grinder doesn’t regulate the size of every particle of ground coffee, but rather just the very largest possible size. This is done by controlling the gap between the burrs. The problem we encounter as grinder builders is that coffee doesn’t break down perfectly evenly. Since coffee is so brittle, it tends to fracture into a variety of different sized particles.

All coffee grinders, at each setting, will produce a variety of particle sizes – from very fine to quite coarse. Different machines will produce different amounts of each size, but on the same set of burrs, the proportion of very fine particles to very large particles is most heavily affected by how large the very largest particles are.

This means that coarser grinding makes for a less even batch of ground coffee. A wide gap between burrs means that each time a coffee particle is fractured into smaller parts, only pieces larger than the gap between burrs will be reduced in size any further.

This can be deceptive, because you look at a grind to see if it’s approximately the right level of fineness, and see fine particles mixed in with coarse ones. This doesn’t mean that the grind is “too fine” however, since grind size is determined by the very largest piece of coffee in your sample. A lot of brewers can get caught in a trap here: a visually “too fine” grind leads to a coarsening adjustment, but there are proportionally more fines at coarser settings, which leads to a coarsening adjustment, which leads to more fines…

So we find ourselves grinding at 31 for a single-cup pour-over with a muddy bed and slow draw-down. The solution here is to adjust our thinking a little bit, and move back down towards the fine end of the grind adjustment. Although the over-all grind will be a little finer, the proportion of fines to large particles will be more amenable to manual brewing.

If you find that you’re still struggling to keep draw-down times at a normal level, try a lighter or gentler pour, or “low and slow” on smaller pour-overs like the V60. This looks like a small, gentle stream of water with less agitation applied to your coffee. You’ll notice that your bed looks less muddy and that water makes its way through the coffee in time. For larger batches like a Chemex, try pouring into the center of the cone and applying water all at once, or “high and dry.” This leads to a bed that is cone shaped as well, and which allows faster passage of water through coffee.

It’s worth noting that, as you use the grinder more and more, the burrs will season and performance will change in positive ways. The biggest change in your grind will happen after about two pounds of coffee have been ground by your machine. After about five pounds, the change in performance will level-off and your Sette will really hit its stride.

The Sette Series has been a real game changer for us at Baratza, down to the way we make our morning cups.