There are many factors that will determine where to grind on your grinder, some of which can create variation from the exact grind setting recommendations here, such as:

• Burr Alignment: Not all grinders come aligned well (laterally or axially) from the factory and even when they do, changing burrs can result in misalignment. This decreases the particle uniformity of the grinder, often producing more fines which may cause astringency in the cup and show as a fine sludge on your brew bed.
• Zero Set-Point: Not all grinders are zeroed (often defined as the point at which the burrs touch or lock). See grind recommendations above for where the zero point is set for various grinders. For most electric grinders, it is the point at which the burrs touch (chirp) and for hand grinders the point at the which the burrs lock (the handle no longer moves freely).  
• Burr Age: As burrs wear from use, the grind quality diminishes slowly which can change where the optimal grind setting is.  
• Brew Technique: Small changes in any of the steps or recipe variables can change the resulting brew by changing the draw-down time or agitation of the coffee.  

The grind settings listed in this guide have been set based on a higher extraction window (19-22% depending on the grinder), and will not be applicable for other extraction "sweet spots" which tend to fall in the 15-17% extraction range.

Water chemistry has a profound effect on the structure and clarity of your coffee.   In addition to taking out chlorine and aromatic taints with a carbon filter (e.g. Brita), the best water formulas decrease the hardness of the water, specifically targeting alkalinity (calcium carbonate). There are two ways to accomplish this at home:

• Water Filteration: You can soften water by running it through an ion-exchange membrane cartridge (plumbed in under your sink) or use a Peak Water jug which, in addition to removing chlorine, lowers the alkalinity and adds magnesium.  
• Making Water: You can use RO (reverse osmosis) water or jugs of distilled and make great water for coffee by adding preformulated mineral packets like Third Wave Water, Perfect Coffee Water, or Aquacode. We've tested our coffee with all of these brands and have had very good results. If you want more customization, you can explore Lotus Water drops.  

Here are the specs for the water we use at the roastery. We try our coffee on various water recipes so there is no need to mimick these specifications which are partly a byproduct of filtering the higher buffer water in our area:

75ppm Total Hardness

Equal parts Calcium to Magnesium

25ppm alkalinity

7pH

It is common to assume fresher coffee is better, but lightly roasted coffee—especially from roasting machines like Lorings—often benefits from rest. Lighter roasted coffee releases carbon dioxide more slowly, and the trapped gas can prevent water from dissolving flavour compounds.  

Our coffee tends to taste its best after 2 weeks of rest time, and continues to taste great past the 6 week mark. It is best to rest your coffee in the sealed bag which is equipped with a one-way valve.  

IIf you won't use your coffee for some time, feel free to put it in the freezer either in the sealed bag or, even better, vacuum sealed.  

This is not to say that the coffee will taste bad if you open it sooner, but the balance and flavour clarity will improve at our recommended rest itimes. If you do open the coffee sooner, extend the bloom phase for percolation brews like V60 and Kalita to actively release CO2 from the grounds..

There is a tendency to adjust many things at once when a coffee is not tasting desirable. Small changes can have a big impact and, particularly with grinders that have more uniform particle distribution, the window in which coffee tastes best can be very narrow and easy to miss. The best way to approach dialling in a recipe is to only change one thing at a time. Our suggestion is to start by solidifying a brew recipe, only adjusing grind setting between brews in small increments.

The brew ratio, agitation, time, and temperature have a big impact on extraction. Equipment like a gram scale, goosneck kettle, thermometer (or temperature variable kettle), and timer can help immensely at producing more consistency in your brews.

This guide was built through carefully brewing over 340 coffees across grinders and brew methods.  

The Coffee:

Three coffees were chosen based on their representation of the widest grind range our coffee has required referencing present and historical data. The coffees used were rested for 3 weeks and all brewing to initially build the guide was done within a one week period.

IIn the subsequent weeks, various coffees were subjected to guide combinations to test the accuracy of the grind ranges.  

The Brewers:

For the V60 recipes, we used a ceramic 02 size V60 with 02 Hario tabbed filters. We tested the recipes on an Origami brewer with the same filters to confrim extraction and drawdown times.  

For the Kalita/Orea recipes, we used a standard steel Kalita 155 with 155 sized Kalita brand wave filters. We tested the recipes on an Orea v3 to confirm extraction numbers and drawdown times.

For Aeropress, we used a standard Aeropress with Aeropress brand filters.

Hario Switch recipes were built using a standard Hario Switch 02 size with Hario tabbed 02 filters.  

The Grinders: All grinders were equipped with stock burrs, seasoned and without much age. with the exception of the EG1 which included SSP Ultra burrs. Each grinder was zeroed based on standard mentioned in the guide (chirp or burr lock).    

Extraction: Extraction measurements were taken for every brew using proper zeroing and refracting protocol on a VST Lab Coffee III Refractometer. Samples were tacken in a pipette immidiately after brew to avoid evaporation, cooled to room temperature, and tested.   Each grinder-coffee-brewer combination was subject to multiple brews across a wider range to test the linearity of extraction through grind changes, as well as triangulating the optimal grind for each permutation to arrive at as exact results possible.