Filter brewing

Super super simple guide to a pour over

14.5 grams dry coffee (coarse ground like brown sugar), 250 grams of water at 93C over the top and an approximately 3 minute brew time .

Coffee brewing calculator

The brewing calculator will give you a rough idea of ratios if you select pour over and input your potential values.

If you are doing a pour over then you know the weight of the initial brew water, you know the weight of coffee, you know the beverage weight and if you have a refractometer, then you know the TDS of the final beverage. In this scenario the only unknown is the absorption coefficient. If you don't have a refractometer you can still guess your TDS by inputting a theorhetical absorption coefficient based on what you would expect for a specific coffee. TDS and absorption coefficient have an inverse relationship so the numbers you get from doing this may be unreliable.

Brewing fundamentals

This is another really simple guide to brewing coffee using a small selection of popular filter brewing methods.

You will need:
- scales (accurate to 0.1g)
- timer
- thermometer (or digital thermostat)
- a kettle

You may like to have:

- refractometer (measures percentage of a liquid that is coffee)

Things you definitely should not use:
- blade grinders/spice grinders (unpredictable results, totally random grind size).
- pre ground coffee (it's stale).

The most popular pour over method for brewing filter coffee is probably the V60 drip filter (it's called a V60 because the walls of the cone are angled thus).

To start with, pour hot water through your filter paper and heat the carafe or vessel into which your beverage will ultimately manifest itself. It is important to prewash filter papers or your coffee will taste mostly of paper rather than coffee. If your coffee usually tastes like cardboard it's either that or you're drinking decaf.

Grinding and extraction

Extraction is the percentage of dry coffee you're taking out and putting into your cup. Total dissolved solids is the measure of how much of the end beverage is coffee. Most people prefer a TDS of around 1.25 - 1.35% [citation required].

As with espresso Time, Temperature and Turbulence define your coffee. Coffee is 30% soluble and 70% cellulose. You want to get the highest percentage of that potential 30% into your cup whilst retaining sweetness, body and finish. Too little is under extraction and you will get nasty, sour shots, too much is over and results in nasty, bitter shots.

(that's just copied from the espresso brewing guide as I was too lazy to rewrite it)

In an ideal world you're grinding all your coffee through a calibrated Mahlkonig EK43 or similar, but chances are, as you're reading this guide you're still wiping the sweat from your brow after a 2 minute slog to get 15grams of ground coffee out of that Hario hand grinder that somebody told you was probably ok.

Grind size

For the purpose of a V60 you probably want 700-1000 microns for South American and Central African coffees and as coarse as you can physically achieve for Ethiopian coffees as they are ridiculously dense and have very slow drawdown times.

In practice, 800 microns is approximately the fineness of coarse brown sugar.
You can adjust your grind fineness after your first brew. If it came out in less than 3 minutes grind finer, if it came out in over 4 minutes then grind corser.

This time limit, along with agitation, is giving the coffee time in contact with water which will, to an extent, decide the strength of the final drink.

If you were to use the TDS calculator on the next tab over, more time, higher temp and more stirring will nudge the TDS upwards and have a knock on effect for other variables in the brew.

So now you're ready to go
14.5 grams dry coffee ground to approximately 800 microns placed evenly into a prewashed filter
250 grams of water at 93C

0 - 30 seconds - pour in 45g of water (approximately 3 times the dry weight of coffee) during this time use a spoon or a spatula to try and achieve an even wetness
30 - 60 seconds - pour in the remaining water at an even rate to 250 grams. Then give it a light circular stir and wait, hoping that it will fully empty in 3-4 minutes.

At this point you either have a vaguely decent coffee or something went wrong. If it's the latter you should probably seek out someone reputable who actually bothered to make a video of this process such as James Hoffman or Tim Wendlebow who will furnish you with a myriad of ways to enhance your coffee brewing prowess and quite possibly persuade you to explore some merchandising options.