How to keep a brew log and make every batch better
Share
The difference between brewing that improves and brewing that just varies
Most people who brew at home have had a batch come out really well and then never managed it again, and it isn't bad luck, it's that nobody wrote anything down at the time. Without notes every batch is a fresh guess, and you end up with a shelf of beer that ranges from very good to fairly ordinary with no idea which of the things you did was responsible for either end of it.
A brew log fixes that, and it doesn't have to be anything clever. A notebook on the shelf above the fermenter will do the job as well as any app.
What to write down
Keep it to the things that actually move the beer, because a log you can fill in while the kettle heats is a log you'll keep using.
- What went in, by weight. The kit or the malt, the sugar or the enhancer, the hops and when you added them, and which yeast.
- Brew day conditions. The date, and what the shed or the laundry was sitting at, because ambient temperature explains more faults than anything else.
- Your original gravity and your final gravity, taken with a hydrometer.
- What fermentation looked like. When it started, when it slowed, and anything odd you noticed on the way through.
- How it tasted at bottling, and how it tasted a month later. Those two are often very different and the gap between them is useful information.
The two readings that explain almost everything
Original gravity is what you measure before the yeast goes in, final gravity is what you measure when it has finished, and the distance between them is how much sugar the yeast actually got through. That's what tells you your alcohol content, and more usefully it tells you whether fermentation finished or quietly stalled on you.
A beer that tastes too sweet with a final gravity sitting well above where it should be has stalled, and that's a fixable problem. The same beer with no readings at all is just a mystery, which is why the hydrometer is the piece of gear I'd buy before almost anything else.
One change per batch
This is the part people skip and it's the part that makes the notes worth keeping. If you change the yeast, the hop timing and the fermentation temperature all in the same batch and it comes out beautifully, your log tells you nothing, because you can't separate which change did it.
Change one thing, write down what you changed and why, then taste the result against the last one. It feels slower and it is much faster, because after 6 or 7 batches you'll know what each lever does in your setup rather than in somebody else's.
The adjustments worth making first
Fermentation temperature is the biggest lever and the cheapest to pull, because a few degrees changes the flavour more than most ingredient swaps will. Hop timing is next, since the same hops added at different points give you bitterness or aroma. Yeast strain after that. Water is real and it matters, but it's the last thing I'd worry about, and if your tap water tastes strongly of chlorine then filtering it is the whole of the fix for most people.
Shop related products
- Coopers Original Draught 1.7kg. This is a steady kit to run your first tracked batches on.
- Coopers Brew Enhancer 2 1kg. Swap this for plain sugar and note what it does to the body.
- Coopers Light Malt Extract 1.5kg. Use this as your next single change after the enhancer.
- Coopers Dextrose 1kg. This is the control to measure the others against.
Did you know we also hold hydrometers and test jars, glass thermometers, heater belts and no rinse sanitiser in the shop that never make it onto the website. Give us a ring on (08) 8536 4333 to check what's on the shelf.
Where to go next
The beer supplies and the wider homebrew range cover the rest, and Brewhilder is handy if you want a second opinion on what to change next.
Worth reading next: Common homebrew problems and how to fix them and How to change the flavour of your homebrew beer.
I'm the one who writes the first three lines of a brew log beautifully and leaves the rest of the page blank.
