Fresh Roast SR800 Guide: Batch Size, Fan and Heat, and a Roast Log That Works

The Fresh Roast SR800 is a hot-air (fluid-bed) home roaster that takes about 8 oz, roughly 225 g, of green coffee per batch and gives you two controls: fan speed and heat. You drive the roast by hand, usually high fan and moderate heat at the start, then less fan and more heat as the beans dry and lighten. First crack typically lands around the middle of an 8–12 minute roast. Because nothing is automated, the roasts that improve are the ones you write down.

This guide covers batch size, how to run fan and heat through a roast, what the SR800's temperature number does and does not tell you, and a simple log you can keep so each batch teaches you something. If you are still choosing a machine, start with our best home coffee roaster comparison.

What the SR800 is (and what it is not)

The SR800 blows hot air up through a glass chamber. The beans float and tumble in that stream, which is why you can watch the colour change and hear first crack clearly. Chaff blows up into a collector on top.

What it is not: a profile roaster. There is no saved curve to load and replay, unlike sample-scale machines such as the Kaffelogic Nano 7e. That makes the SR800 a better teacher (you feel every change you make) and a harder machine to repeat exactly. A written log closes most of that gap.

Batch size: start smaller than the rating

The 225 g rating is the top of the range. At a full load the beans move slowly at the start, when they are heaviest, and the bottom of the bed can scorch while the top lags behind.

A practical way to find your batch size:

1. Start around 150 g. The beans should circulate from the first minute on a high fan setting.
2. Add weight in 20–25 g steps over later roasts while the bed still moves freely at the start.
3. Stop adding when you need maximum fan for more than the first minute or two to keep the beans moving.

An extension tube raises the chamber height so a fuller load can circulate without throwing beans into the chaff collector. If you want to roast near the full rating every time, it is the accessory owners recommend most.

Whatever size you settle on, keep it constant. Changing the batch weight changes every timing in the roast, and it makes your log hard to compare.

Running a roast: fan first, heat second

Fan speed does two jobs on a hot-air roaster: it keeps the beans moving and it carries heat away. Turning the fan down makes the roast hotter, often more than turning the heat up. So a typical SR800 roast has three phases.

1. Drying (roughly the first third). Fan high enough that the whole bed tumbles, heat moderate. The beans go from green to yellow and smell grassy, then like bread.

2. Browning (middle third). As the beans lose water they get lighter and start to fly higher. Step the fan down so they keep tumbling without flying into the chaff collector, and raise the heat in steps. Make one change at a time and note the minute.

3. First crack and development. First crack is a popping sound like popcorn, quieter than popcorn. From here you are developing the roast. Many roasters ease the heat back slightly at first crack so the roast does not race ahead, then end the roast with the cooling cycle when the colour and the time after crack reach their target. Read our guide to first crack for what is happening inside the bean.

For light-to-medium roasts, a common target is a development time (time from first crack to the end of the roast) of about 15–25% of the total roast. On a 10-minute roast that is roughly 1.5 to 2.5 minutes after first crack.

Things that change your roast without you touching a button

• Mains voltage. Hot-air roasters are sensitive to it. The same settings can roast faster or slower on another circuit or at another time of day.
• Room temperature. A cold garage or balcony slows the roast; a hot kitchen speeds it up.
• Bean age and density. Older, drier green coffee takes heat faster. If a bag has been around a while, see how long green coffee beans last.

This is the main reason to log: when a roast goes differently, your notes tell you whether it was you, the bean or the room.

What the temperature on the display means

The number on the SR800 is an air temperature from a sensor near the chamber. It is not the bean temperature, and it does not match the bean-probe numbers that drum roasters publish. Use it in two ways only:

• As a relative reading between your own roasts on the same machine.
• As a warning when it climbs much faster than usual for a setting, which usually means the fan is too low for the batch.

For the decisions that matter, use first crack, colour, smell and time. Some owners add a thermocouple and graph the roast in roasting software. That is a project in itself; it is not needed to roast well on an SR800. If you want to understand the options, see our overview of coffee roasting software.

A roast log for the SR800

A hand-driven roaster needs a log more than a profile roaster does, because the roast exists only in what you did. Record these for every batch:

Roast loss is the percentage of weight the beans lose: (green weight − roasted weight) ÷ green weight. Light roasts typically lose around 12–14% and medium roasts around 14–16%, though beans and machines differ. If two roasts with the same settings give very different losses, something else changed: voltage, room, batch size, or the bean.

An example log entry (illustrative)

The numbers below show how an entry reads; they are an example, not a measured result.

Washed Ethiopian, 170 g green. Fan 9 / heat 4 at start. Fan 7 at 3:00, heat 6 at 4:00, fan 6 at 5:30. First crack 7:10, heat 5 at first crack. Cool at 9:20. Roasted weight 147 g (13.5% loss). Development 2:10 (23%). Tasted after 5 days: good, bright, a little thin. Next time: end 15 seconds earlier and compare.

One change per roast, written down next to the result, is how you get from "it was fine" to a roast you can repeat.

Keep the log in BrewedLate

You can keep this on paper, but a log you can search is easier to learn from. The BrewedLate roast tracker takes a roast without a machine file: enter the bean, green and roasted weights, first crack and total time in seconds, and your notes. It works out roast loss, how long the coffee has rested, and the roast level band, and after you taste it you record whether it was good or which fault it had. It also keeps track of how much of each green coffee you have left, so you know when to reorder. Sign up free and log your next SR800 roast.

If you are new to roasting, our home coffee roasting beginner's guide covers the stages of a roast in more detail.

FAQ

How much coffee can the Fresh Roast SR800 roast?

The SR800 is rated for about 8 oz (roughly 225 g) of green coffee per batch. Many owners roast a little less, around 150 to 200 g, because a smaller load circulates more freely and roasts more evenly. An extension tube lets the chamber take a fuller load while keeping the beans moving.

How long does a Fresh Roast SR800 roast take?

A typical light-to-medium SR800 roast runs about 8 to 12 minutes, with first crack somewhere in the middle of that window. The exact time depends on batch size, your heat and fan steps, room temperature and your mains voltage.

Does the SR800 show bean temperature?

No. The display shows an air temperature from a sensor near the chamber, not the temperature of the beans. Treat it as a relative reading for comparing your own roasts, and use first crack, colour and time as the real markers.

What is the difference between the Fresh Roast SR540 and SR800?

Both are hot-air roasters with stepped fan and heat controls. The SR540 takes a smaller batch, around 4 oz (about 120 g), while the SR800 takes about twice that and has more power to push a bigger load. Most new buyers now choose the SR800.

How should I log Fresh Roast SR800 roasts?

Write down the bean, green weight, roasted weight, the time and setting of every fan or heat change, first crack time and total time, then taste the coffee after it rests and record whether it was good or had a fault. Roast loss and development time follow from those numbers.

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