What's Different This Fall
Fall tap water runs 5–8°F cooler than summer. That shifts extraction down by 1.2% on average — and fixes most over-extraction bitterness without changing your beans.
Municipal water treatment changes in October. TDS can drop 30–50 ppm. If your cup tastes flat this month, it's probably your water, not your grind.
Ethiopian and Colombian new-crop beans land in October. They degas differently — expect 5–7 days longer rest before peak flavor vs. last season's lots.
Pre-Season Prep Checklist
Complete these before October 15. Each item takes under 10 minutes.
Test Your Water TDS
Buy a $15 TDS meter. Measure your tap water. Ideal range for brewing: 75–150 ppm. Below 50? Add Third Wave Water minerals. Above 200? Use filtered or distilled + minerals.
Calibrate Your Grinder
Burrs shift with temperature and humidity. Run 20g through at your usual setting, check particle consistency. Fall humidity is lower — you may need to go 1–2 clicks finer to maintain the same extraction.
Stock New-Crop Beans
Order fresh Ethiopian Yirgacheffe or Colombian Huila. Roast date within 7–21 days. New crop has denser cell structure — extract at 203°F instead of 200°F for full sweetness.
Verify Scale Accuracy
Weigh a nickel (5.0g). If your scale reads 4.8g or 5.2g, replace it or note the offset. A 0.3g error at 18g dose = 1.7% ratio error = visible extraction shift.
Descale Your Kettle
Mineral buildup insulates the heating element and creates temperature lag. Citric acid soak for 30 minutes. Your kettle will hit target temp 15–20 seconds faster.
Fall Brewing Calendar
The Extraction Yield Guide
Extraction yield is the percentage of coffee solids dissolved into your cup. The Specialty Coffee Association defines the ideal window at 18–22%. Here's how to hit it every time.
Understand the Variables
Extraction yield is controlled by four variables: grind size, water temperature, brew time, and brew ratio. Change one at a time. Never adjust two simultaneously — you won't know which variable fixed (or broke) your cup.
Under-extraction (<18%) tastes sour, thin, and salty. Over-extraction (>22%) tastes bitter, astringent, and hollow. The sweet spot tastes sweet, balanced, and clean.
Lock Your Brew Ratio First
Start with 1:16 (1g coffee to 16g water). This is the SCA standard and your anchor point. For a 300ml cup: use 19g of coffee. For 500ml: 31g. Weigh everything — scoops lie.
If your cup tastes weak at 1:16, tighten to 1:15. If it's too intense, open to 1:17. Never go below 1:14 or above 1:18 for filter coffee.
Set Water Temperature by Season
Fall default: 200°F (93°C). This is 2–3°F cooler than summer brewing because beans roasted in cooler ambient temps retain more moisture and extract faster.
Light roasts: 203–205°F. Medium roasts: 198–202°F. Dark roasts: 190–195°F. Use a thermometer — guessing costs you 2–3% extraction yield.
Dial Grind Size by Taste, Not Chart
Start medium-fine (table salt consistency). Brew a cup. If sour → grind finer. If bitter → grind coarser. Adjust in small increments — 1 click on a Comandante, half-step on an Encore.
Each full grind step changes extraction by approximately 0.5–1.0%. Most home brewers are 2–3 clicks too coarse, which is why their coffee tastes sour and they compensate with more beans.
Time Your Brew
Pour-over total brew time: 2:30–3:30 for V60, 3:30–4:30 for Chemex. French press: 4:00 exactly. AeroPress: 1:30–2:30 depending on recipe.
Time is a diagnostic, not a target. If your grind and ratio are correct, time falls into range naturally. If time is way off but the cup tastes good, trust the taste.
Seasonal Data Panel
Post-Season Wrap-Up
Store Remaining Beans Properly
Vacuum-seal any beans you won't use by December 1. Freeze at -5°F. They'll hold extraction potential for 3–4 months. Thaw sealed — never open a frozen bag until it reaches room temp or condensation will ruin them.
Log Your Final Recipes
Write down your best-performing recipe: dose, grind setting, water temp, ratio, brew time, and the bean. This becomes your baseline for next fall. You'll forget the specifics by January — trust the log, not your memory.
Transition to Winter Brewing
Winter tap water runs colder and often has higher mineral content from treatment changes. Plan to bump water temp 2–3°F and test TDS again in December. Cold brew season is over — lean into hot methods and richer roasts.