All-Grain Brew Day — End-to-End Walkthrough

A start-to-finish walkthrough of a brew day on an electric all-in-one, which is what both rigs behind this journal are: a BrewZilla 65 L Gen 4.1 with a Red Reaper counterflow chiller and a Digiboil 30 L for sparge water here in Wellington, and a Grainfather G30 with a 20 L water kettle at Owen’s in Auckland. Different vessels, near-identical process — mash and boil in one heated vessel with a grain basket and a recirculation pump, sparge water heated separately, ferment in pressure-capable All Rounders under RAPT control.

Every step says what to do and why, with the numbers we actually run rather than generic ones. Where experience has moved us off the textbook figure, it says so.

Brewing on something else? Three-vessel and BIAB setups separate wort from grain quite differently, and the sparge section in particular will not map cleanly. The Valley Brewers walkthrough covers all three setups side by side and is the better starting point if you are not on an all-in-one.

The three golden rules

1. Sanitation beats everything. Once wort drops below ~80 °C it can no longer protect itself. From that point on, anything that touches the beer — chiller, tubing, taps, fermenter, scissors, yeast packet, your hands — must be sanitised. The most common cause of a ruined batch is a sanitation slip late in the day when you are tired. Sanitise, sanitise, sanitise.
2. Write everything down. Target vs actual gravity, volumes, temperatures, timings, what went wrong. You cannot improve a process you do not measure, and next brew will thank you.
3. Mise en place. Weigh, measure, and lay out everything before you start heating water. Brew day moves in real time — you do not want to be scrambling for hops while the boil climbs toward a boil-over.

A full brew day is 4–6 hours plus cleanup. Most mistakes happen in the last hour when concentration fades. Slow down when you are tired.

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Stage 0 — Prep (night before or first thing)

Read the recipe and know your numbers. Before touching equipment, write down your targets: batch size into the fermenter (L), original gravity (OG), final gravity (FG), IBU, mash temperature and time, and your water volumes.

Work out your water volumes. Total water needed is roughly:

batch size + grain absorption + boil-off + equipment/trub losses

As rough starting figures on an all-in-one: grain absorbs ~0.8–1.0 L per kg of grain, boil-off is ~3–4 L per hour, and you lose ~2–3 L to trub and deadspace. Split the total into mash water (in the main vessel) and sparge water (in a separate heater or kettle). Your recipe software usually gives these two figures directly — use them.

Treat the water for chlorine / chloramine. Tap water is usually chlorinated. Chlorine and chloramine react with the malt to produce a plaster / band-aid off-flavour (chlorophenols). Add campden (sodium/potassium metabisulphite) at one crushed tablet per 75 L — so half a tablet covers roughly 38 L, about right for a single 23 L batch’s total water. Stir, and it neutralises both within a couple of minutes. Do this to all brewing water (mash + sparge).

Weigh and crush the grain. If you crush your own, aim for a crush that splits the husk but leaves it largely intact — too fine and the bed compacts and you get a stuck mash; too coarse and efficiency drops. Bag or bucket the milled grain.

Weigh the salts — mash and sparge separately. Water chemistry salts (gypsum, calcium chloride, etc.) are usually split between mash and sparge water. Weigh each portion into its own labelled cup so you do not dump the lot in one place. Keep any acid (lactic / phosphoric) for mash-pH adjustment to hand.

Weigh and bag the hops by addition. Weigh each hop charge into its own labelled bag or container — bittering, each flavour/late addition, and whirlpool — and write the time on each (e.g. “60 min”, “15 min”, “whirlpool 80 °C”). Doing this now means that during the boil you just grab the next bag.

Pre-brew checklist:

• Recipe printed/open; targets written down
• Mash + sparge water volumes calculated
• Campden added to all water
• Grain crushed and weighed
• Mash salts + sparge salts weighed (separate cups); acid to hand
• Hops weighed, bagged, labelled by addition
• Whirlfloc tablet + yeast nutrient set aside
• Yeast located (and out of the fridge to warm up if pitching dry)
• Chiller, tubing, taps, paddle, hydrometer/refractometer all clean
• Fermenter, lid, airlock ready to be cleaned + sanitised
• Sanitiser (StarSan) and cleaners (brewery wash, sodium percarbonate) on hand
• Spray bottle of water near the kettle (for boil-over control)

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Stage 1 — Setup and water

1. Fill the main vessel with your mash water and the sparge heater/kettle with sparge water.
2. Add the mash salts and any mash acid to the mash water; add the sparge salts to the sparge water. Stir to dissolve.
3. Start heating the mash water toward strike temperature and put the sparge water on to warm in parallel.

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Stage 2 — Strike and mash in

Strike temperature. On a full-volume all-in-one you generally heat the mash water to your target mash temperature (most ales: 65–67 °C for a balanced beer; lower = drier/more fermentable, higher = more body). Adding cool grain pulls the temperature down a degree or two, so some brewers strike 1–2 °C high and let it settle — check your system’s behaviour and adjust.

Mash in (dough-in). With the water at strike temp:

• Stir the grain in steadily while gently recirculating. Add grain in stages rather than all at once.
• Break up any dough balls — pockets of dry flour trapped in clumps never convert and drag your efficiency down. Dig the paddle to the bottom and fold.
• Do not recirculate too fast. A hard pull compacts the grain bed down onto the false bottom, chokes the flow, and gives you a stuck mash. Keep the recirculation gentle — a slow, steady trickle over the top is all you want.

Check and record mash pH. Once mixed and settled (~5 min in), measure mash pH with a meter or strips. Target 5.2–5.4 (room-temp reading). If it is high, add a little acid and re-check; if it is already in range, leave it. Record the number.

Mash. Put the lid on, hold the target temperature for the mash time (typically 60 min), and keep a gentle recirculation running to hold an even temperature through the bed. Resist the urge to crank the pump.

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Stage 3 — Mash out and sparge

Mash out. Raise the mash to ~75–78 °C and hold for ~10 minutes. This stops enzyme activity (locking in your fermentability) and thins the wort so it runs off the grain more freely.

Sparge — rinse the sugars from the grain. Sparging recovers the sugar still clinging to the grain bed with fresh hot water:

1. Lift the grain basket to the half-way point and let it drain, then begin the sparge.
2. Gently pour the ~75 °C sparge water over the top of the grain bed — slowly and evenly, so it percolates down rather than channelling. A jug, a sparge arm, or a colander to diffuse the pour all help.
3. Lift the basket all the way up once the sparge water is mostly through, and let it drain fully.
4. Try not to disturb or stir the grain bed. The settled bed is itself a filter; stirring it pulls haze and tannin into the wort. Only stir as a last resort if flow has genuinely stuck.

Take a pre-boil gravity reading. Pull a small sample, cool it, and read it on a refractometer or hydrometer. Compare to your recipe’s pre-boil target — this is your first honest read on mash efficiency. Record it.

Worth calibrating your expectations here. Across this archive the BrewZilla runs a median brewhouse efficiency around 73 % and the Grainfather around 65 % — an eight-point gap between two similar rigs, consistent over seventy-odd batches each. If you are brewing a recipe from the other rig, that difference is real and you should scale the grain bill rather than accept the miss. The numbers and the method are in Reading Gravity, ABV & Efficiency.

Start the ramp to boil. Once you have enough wort through (~10 L), start raising the kettle temperature toward boiling so you are not waiting around. Bring the sparge water up to ~95 °C and edge it toward ~102 °C so that, as the last of it dribbles through, the kettle holds a constant rolling boil rather than stalling each time cooler water arrives.

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Stage 4 — The boil

Remove the grain basket. Lift it clear and set it in a clean bucket to catch drips. Optionally collect the last ~500 ml of runnings and add them to the kettle — only if there is at least 45 minutes of boil left, so the extra wort is fully boiled and any late, tannic runnings are diluted out.

Watch for the hot break and prevent a boil-over. As the wort approaches the boil, proteins coagulate and a thick foam (the hot break) rises fast. This is the classic boil-over moment. Be ready:

• Break the surface foam with the mash paddle, and/or
• Keep a water spray bottle to hand and spritz a hole in the foam. Knocking the foam down releases the trapped steam bubble and stops a wave of boiling wort going over the side.

Once the break settles, it boils calmly.

Boil uncovered, and boil hard. Sixty minutes is the usual default, but the number depends on the grist:

On a pilsner-malt beer, boil 90 minutes. Pilsner malt carries far more SMM — the precursor heat converts into DMS, the cooked-corn fault — than standard pale malt. A vigorous rolling boil with the lid off and steam genuinely escaping is what drives it out; a lid partly on, or anything letting vapour condense and run back in, puts it straight back.

There is no fermentation fix for DMS. It is a boil problem, and once it is in the beer you are stuck with it — one of the few places worth being dogmatic. Keep a steady rolling boil, vigorous but not so hard it boils dry.

Add the hops at their scheduled times. Drop each weighed bag in at its mark:

• Bittering hops at the start of the boil (e.g. 60 min) for IBU.
• Flavour / late hops in the back half (e.g. 15–20 min) for hop character.

At 10 minutes left:

• Add the whirlfloc tablet (kettle fining — helps proteins clump and drop out for a clearer beer).
• Add yeast nutrient — about 5 g for a 23 L batch is a good rule of thumb.
• Drop the chiller coil into the boiling wort so the last 10 minutes of boil sanitises it.

Sanitise your transfer paths. Before the boil ends, recirculate boiling wort through the recirculation arm and also out through the lower tap for a short spell. This sanitises both possible transfer routes, so whichever one you use at transfer is already clean. (Re-route carefully — boiling wort burns.)

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Stage 5 — Whirlpool and chill

At 0 minutes (flame/element out):

1. Turn the heat off and set the target to 75–80 °C for the whirlpool.
2. Turn the cooling on for the first part only, until the wort reads about 85 °C, then turn the cold water cooling off. The residual heat in the system will coast the temperature down into the 75–80 °C whirlpool window — this avoids overshooting cold.
3. Add the whirlpool hops once the wort is at ~80 °C. Below boiling, the hops give aroma and flavour without scrubbing it off as steam, and below ~80 °C you avoid harsh extraction. Hold for 20–40 minutes depending on the recipe.
4. Recirculate during the whirlpool to increase chilling contact and hop interaction, and to spin the trub into a cone.

Take an OG / post-boil gravity reading while you wait (cool the sample first). Compare to target — together with your final volume this tells you your brewhouse efficiency. Record OG and the actual volume.

Meanwhile, prepare the fermenter. While the whirlpool holds:

• Clean it first: cold-water rinse → wash with brewery soap → a sodium percarbonate wash to strip any organic film and smell → rinse.
• Then sanitise with StarSan (the acidic no-rinse sanitiser). A clean surface is a prerequisite — sanitiser does not work on a dirty one.

Resume chilling to pitch temperature. Once the whirlpool is done, turn the cooling back on and chill toward pitch temperature, usually 18–20 °C for ales. Recirculate to speed it up.

Chill briskly once the whirlpool is done. Wort lingering in the 60–80 °C band keeps converting SMM into DMS with no boil running to drive it off, so a slow chill can undo a good 90-minute boil. Recirculating hard through the chiller drops the whole volume together — run the pump properly rather than letting it drift down.

Note the tension with the whirlpool itself, which deliberately holds the wort at 75–80 °C for 20–40 minutes. That is a real trade: hop aroma against DMS. On a pale, pilsner-heavy beer keep the stand at the shorter end; on a hop-forward beer with a pale-ale base the DMS risk is much lower and the stand can run long.

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Stage 6 — Transfer and pitch

Transfer the cooled wort to the fermenter — either pump it through the recirculation arm or run it straight out the lower tap. (Because you recirculated boiling wort through both paths in Stage 4, either is sanitised.)

Get oxygen into it on the way in. This is the one step where you want oxygen, and it carries more weight than almost anything else on this page.

Yeast uses dissolved O₂ to build the sterols and unsaturated fatty acids that make healthy cell membranes. Under-oxygenated wort means rigid membranes, and that is where fusel alcohols, excess esters, a long lag phase, incomplete attenuation and lingering acetaldehyde all come from — plus reduced capacity to clear diacetyl later, because that reduction is energy-hungry and the energy depends on membranes built at the start. If you put effort into one off-flavour control, put it here.

Let the wort splash and tumble as it fills. For a fresh dry pitch that is genuinely enough — dry yeast is propagated aerobically and arrives carrying those reserves, which is why the manufacturers say it does not need oxygenating.

Everything else needs more. A harvested slurry has spent its reserves, liquid yeast was never packed with them, and wort above ~1.065 adds osmotic stress on top. There, aerate deliberately — see Yeast Handling.

Take your OG and volume now if you have not. Record actual OG and actual volume into the fermenter — this is your real starting point.

Pitch the yeast. Sanitise the scissors and the outside of the yeast packet, carefully open them, and tip the dry yeast evenly over the surface of the wort. (For dry yeast, sprinkling onto well-aerated wort at the right temperature is fine; follow the manufacturer’s guidance if it calls for rehydration.)

Seal up. Fit the sanitised lid, fit the airlock/bubbler with sanitiser in it to seal the system against airborne contaminants, and move the fermenter somewhere as close to target temperature as possible.

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Stage 7 — Fermentation

Temperature schedule. The first day is when most off-flavours (fusel alcohols, excess esters) are produced, so start cool and ramp up:

• First 24 hours: 16–18 °C — keeps the vigorous early phase clean.
• Main growth: 18–20 °C — healthy, complete fermentation.
• Cleanup: ~20 °C — let it finish and clean up after itself.

Monitor it. Watch with a floating hydrometer sample or an inline tilt/RAPT pill. Fermentation is done when gravity is stable for 2–3 consecutive days at or near your target FG — not when the airlock stops bubbling (an unreliable signal).

Diacetyl (VDK) rest. Near the end of active fermentation, let the temperature free-rise to ~20–21 °C and hold a couple of days.

The warmth is doing two jobs, and it is worth knowing both. It speeds up the slow chemical step that converts the precursor into diacetyl in the first place, and it keeps the yeast healthy and in suspension so it can then reduce it. Miss either and the rest fails — which is why cooling to “protect” a beer is backwards, and why a rest measured in calendar days rather than by testing is meaningless. Butterscotch, Toffee & Hop Creep has the forced test that actually settles it.

Dry hopping (if the recipe calls for it). Add dry hops late — typically as active fermentation winds down or just after — to capture aroma and, with some contact during active yeast, biotransformed character. Keep oxygen pickup to a minimum when you open the fermenter, and dry hop warm (fermentation temperature), not cold.

Cold crash before packaging. When fermentation is complete (and any dry-hop contact time is up), drop the temperature to ~1–4 °C for 24–48 hours. The cold drops yeast and hop debris out of suspension, giving a clearer, cleaner beer that leaves less sediment in the package.

Step down rather than shocking it. With a controlled chamber there is no reason not to — 20 °C → 12 °C → 4 °C over a couple of days beats slamming straight to 1 °C. A sudden cold shock can halt the yeast’s flocculation machinery partway, leaving a stubborn haze that more time will not fix; and haze particles given time form dense, settleable aggregates rather than the loose micro-gels that come out of a fast crash.

On a hazy, crash fast on purpose. The paragraph above is written for a beer meant to clear, and it inverts for one that is not. Those loose micro-gels are the specification rather than the fault, so a hazy is better served by going straight down and packaging soon after. The bigger lever is time rather than rate: how long it sits cold governs how much drops out, which is why an overnight crash and straight into the keg is the right shape for the style.

A fermentation fridge is already the gentle end of the range. Cooling 24 litres through seventeen degrees is around 1,600 kJ, and a domestic fridge fighting its own insulation takes twelve to twenty-four hours to do it — roughly a degree an hour. The “rapid cooling” that arrests flocculation in the literature means glycol jackets pulling several degrees an hour through a thin-walled tank. “Straight to 3 °C” on a fridge is not that, so do not over-correct for a problem the equipment cannot cause.

Cap the differential if the controller can. What actually damages flocculation is the gradient rather than the destination: blasting cold air chills beer at the wall far faster than beer at the centre. Reading wort temperature from a probe in the beer and limiting how far below it the chamber may drive — 5 °C is a reasonable cap — makes the compressor cycle instead of running flat out, so the descent is limited by the beer’s own thermal mass. It still finishes inside a day.

A fast crash on a finished beer does not stress the yeast. Stress-derived off-flavours — fusels, excess esters, acetaldehyde — come from yeast under stress while actively fermenting. At terminal there is no metabolism left to distort. Cold shock on a dormant population shows up as haze, not flavour, and autolysis wants warmth and time, so cold is what prevents it rather than what causes it.

Don’t leave it on the cake for weeks after FG. Once the cleanup is done the yeast has nothing left to contribute and slowly starts breaking down, giving meaty or savoury autolysis notes and hurting head retention. Days are fine at this scale; a month is asking for it.

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Stage 8 — Packaging (bottling)

Sanitise everything, again. By now it has been a long process across several days. Every surface that touches finished beer must be sanitised.

Bottle prep. Bottles must be clean before they are sanitised — no crud, no dried-on dregs. The habit that makes this easy: rinse every bottle right after you drink from it and never let beer dregs dry inside. For stubborn residue, a sodium percarbonate soak lifts it. Once a bottle is genuinely clean, it only needs a sanitise (StarSan) before filling.

Priming sugar. Bottle conditioning carbonates the beer by feeding the remaining yeast a measured dose of sugar in the sealed bottle. The simple, repeatable method is carbonation drops: 2 drops per 750 ml bottle (1 per ~330 ml). (Bulk priming — dissolving a calculated dose of dextrose into the whole batch before bottling — is an alternative once you are comfortable.)

Bottling run. Set up the sanitised fermenter with a sanitised bottling wand. If you cold-crashed, let the beer settle and draw from above the sediment. Drop the priming sugar into each bottle, fill with the wand (it fills from the bottom and displaces air, minimising oxygen and foaming), leave the correct headspace, and cap.

Condition. Leave the bottles somewhere around 20 °C for ~2 weeks so the yeast carbonate the beer, then move them somewhere cool. Chill before drinking.

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Cleanup (right after brew day)

Clean while things are still wet — dried-on trub is far harder to remove.

1. Tip out the spent grain and trub, rinse the vessel and all parts.
2. Wash with brewery soap to cut residue.
3. Run a sodium percarbonate cycle to strip organic matter and any lingering smell from the kettle, pump, arm, and tubing.
4. Rinse with water, then a final rinse with StarSan — the acidic sanitiser helps passivate and protect the stainless.
5. Dry everything thoroughly before storing, so nothing sits damp.

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Sanitation and chemicals — quick reference

The 80 °C rule: anything that contacts the beer once it is below ~80 °C must be sanitised first. Clean then sanitise — sanitiser cannot do its job on a dirty surface.

Numbers at a glance (typical ale, ~23 L)

These are starting points for a standard ale. Always defer to your specific recipe and yeast strain.