Sourdough Mate

Electric Heat Fermentation Box — USB + Foldable

Name: Electric Heat Fermentation Box — USB + Foldable
Brand: Sourdough Mate
SKU: CREAM HEAT BOX
Price: 34.95 AUD
Availability: InStock

$34.95 AUD

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Color Brown Cream

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Back in stock!

Gentle warmth. No complicated settings.

Cold kitchen? Winter sluggishness slowing your starter or dough to a crawl? This is the fix — and it won't cost you $95.

Most proofing boxes are bulky, expensive and packed with dials you'll rarely use. Ours is the opposite. At just $34.95, it’s a simple and affordable way to create a gentle, stable environment to support healthy fermentation—especially during cooler weather.

There are no settings to adjust or temperatures to monitor.

USB power means you can run it from a laptop, wall plug, or power bank. When you're done, it folds flat and slides into a drawer. And because it's so light, your starter doesn't have to skip a feed when you travel.

Affordable, foldable, transportable — and built to actually fit our sourdough mixing bowls.

What's included:

Foldable heat proofing box, foil-lined
USB cable
Low-wattage heat mat for gentle even heat distribution

Specs:

Power: USB (5V2A)— works with USB-A chargers and USB-A power banks
Heat output: one constant optimal temperature made for sourdough fermentation
Folded size: 32.5cm x 30.5cm x 3.5cm thick
Open size: 32cm x 30cm x 20.5cm height
Weight: 200g

Please note: You will need a USB-A power source (such as a wall plug, power bank or laptop) with a minimum output of 5 volts and 2 amps. Some older USB power adapters may provide less than 2 amps and will not supply enough power for the unit to operate correctly.

How does the box work?

The heat box maintains a gentle fermentation environment of between 21-28°C, with the internal temperature varying slightly depending on the ambient room temperature and the amount of starter or dough inside.

Please note: If the surrounding environment is particularly cold, or if you’re fermenting a larger quantity of starter or dough, the temperature inside the box may be slightly lower. This is completely normal, as the heat box is designed to provide gentle, gradual warming rather than direct heating.

Here's the simple routine:

1. Plug it in

Connect the USB cable to a power bank, USB wall adapter, or any compatible USB power source. The box will gradually warm to steady range between 21-28°C. The time and temperature will vary depending on your room temperature and the amount of starter or dough inside.

2. Place your starter jar or dough inside

Place your starter jar or dough into the box. If you're using our Sourdough Mate Starter Jar, remove the silicone seal to allow carbon dioxide to escape during fermentation. If you're using a standard jar, keep the lid loosely fitted or only lightly screwed on.

Pro tip: Place a small cooling rack inside the heat box to keep your starter or dough slightly elevated above the heating pad. This helps distribute the warmth more evenly for consistent fermentation.

3. For best results, keep the box closed during use

To maintain a consistent temperature, avoid opening the box unnecessarily while your starter or dough is fermenting. Each time the box is opened, warm air escapes and the internal temperature can fluctuate, which may extend fermentation times.

Of course, you can check on your starter when needed, but frequent opening may slow the warming process and reduce temperature stability.

If you'd like to lower the temperature slightly, simply leave the zip partially open to allow a small amount of heat to escape.

4. Check after 3 hours (earlier if your starter is quite active)

Typically at 24-28°C, a starter fed with a 1:1:1 feeding ratio (equal parts starter, flour, and water) can become active surprisingly quickly, especially once your starter is fully established and in good rhythm.

Start watching for bubbles and signs of rise around the 3-hour mark. Most healthy starters fed with an equal parts ratio will hit their peak within 3 to 6 hours at these temperature ranges. Our preference is to use our active starter when it is "young" or on its way up as this provides a more mild taste to bread.

Sustainable Packaging 🌱

We’re committed to reducing our environmental footprint wherever we can. We up-cycle boxes whenever possible, minimise plastic throughout our packaging, and use home-compostable mailing bags where possible.

Small, thoughtful choices help us deliver your order safely while using more sustainable packaging wherever possible.

Same or Next Day Dispatch

Most orders are processed as quickly as possible, with tracking details emailed to you on the same or next business day.

We exclusively use Australia Post for all deliveries, as they offer the most reliable service. Shipping rates are calculated and displayed at checkout.

You can find more details on our Shipping Policy.

Click & Collect (unavailable)

We’re an online store, and while all our items are carefully packed and shipped from our Mount Martha warehouse, we’re not set up for in-store pick-up at this time. We apologise for any inconvenience and appreciate your understanding.

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Use & Care Instructions

Use & care instructions for all our products.

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5 stars: 33 (87%)
4 stars: 4 (11%)
3 stars: 0 (0%)
2 stars: 0 (0%)
1 star: 1 (3%)

Some of the reviews shown are from related products the merchant grouped with this one.

Works well

This works so well for getting your starter to rise a little quicker on these cold Aussie nights.

This is great!

This is great! I was prepared to put my sourdough bread making on hold for winter, it's been SO cold. But this box has solved my problem!
My only tip would be to place a rack on top of the heating pad to stand your containers on. Direct contact caused dried stuck-on edges -maybe I left it in too long, but the rack solved the problem.

Not happy

It keeps cutting out and it doesn’t keep the temperature

my kitchen was too cold

my kitchen was too cold and i was wondering why nothing was proving fast this has really helped and now my stater and dough are proving well great addtion

Electric Heat Fermentation Box

Heat box

I had a problem with my gluten free sourdough starter. It suddenly became inactive. I would feed it and still nothing.

After trying everything I could think of, I came to the conclusion that it may be the drop in temperature.

I purchased this heat box and couldn't be happier.

It would be good if it plugged straight in rather than having to leave the box slightly unzipped for the heating mat lead. Otherwise, this box has saved my starter!!

Thank you ☺️

great works well i have already sent u a message

Great product ! My sourdough starter is now a repeatable process and this makes a big difference

Great product ! My sourdough starter is now a repeatable process and this makes a big difference to my sourdough bread. Great results every time !

Best piece of equipment for preparing sourdough

Best piece of equipment for preparing sourdough you can buy

It was a birthday present for a family member

It was a birthday present for a family member and they love it

I love this new heat pad for my mother starter it’s simply the best especially for winter so am able to bake sourdough 🙏😘🥖🌾💧

Really enjoying having the fermentation box, taking the guess work out of what temperature my dough is proving at.

Perfect Heater

Amazing heater to keep on baking through winter

It gave my starter the CPR it needed in winter

My starter was struggling to rise in winter. I nearly gave up trying to keep it at the right temperature. Then my heat box arrived….a few hours in there and my starter had doubled and bubbling. Bulk proofing was quicker in the heat box too. If it wasn’t for this awesome box, I would have given up my sourdough hobby.

The electric fermentation box has been a lifesaver in proofing my sourdough

The electric fermentation box has been a lifesaver in proofing my sourdough, it has been sow cold in my kitchen this winter

Great little warmer

Absolutely love it

Perfect warmer pad! I had tried many of the cheap brands on the market and wish I had have gone straight to this! Consistent even temp and my starter is going well even in freezing cold melbourne temperatures!

Excellent product

Perfect for winter! I also use it to ferment

Perfect for winter!
I also use it to ferment Kefir!

Excellent

Excellent, works perfect, a very good buy, should have bought it earlier, quite chuffed with it.

It does the job

Works well, but does seem to run a little too warm. I’ve needed to turn it off for periods of time to regulate.

Happy starter, happy baker!

I just love this compact heating pad. I live in Canberra and struggled to get my starter going on those cold days when I have to go out. Now I can go out for the day knowing that my starter is warm and happy and ready to be used when I come home.
The pad is compact, easy to store and simple to operate.

Awesome! Just beed to get making!

I’m happy with this product and it’s a great price

I’m happy with this product and it’s a great price. The mat created a warmer than preferred environment as there’s no temp gauge but that’s to be expected for the cheaper price point.

If your house is cold, you need this!

This proofing box was exactly what I needed to get my starter going as my house is so cold even keeping it in the oven or microwave wasn't enough. The day I put her in this she instantly became active and I was able to bake with her within a week. It has also been great for proofing bread in my cold house.

So easy to use!

I have been searching for a reliable AUS warming plate for a reasonable price and couldn't find one. Then I came across this on on IG. It is great! It's so easy to use. I would highly recommend purchasing this warming plate if you are after one.

It’s simple piece of equipment but all that is needed to keep my sourdough at a constant warm

It’s simple piece of equipment but all that is needed to keep my sourdough at a constant warm temperature and also the dough at the various stages of the sourdough process. It has been a game changer in successfully making sourdough during winter.

Upped my game to a new level

This fermentation box has brought a whole new level of predictability when doing bulk fermentaion - no more guessing. I put a rack over the heating pad to keep the bowl off the direct heat and it works a treat. I use the fermentaion box every time.

Honestly a game changer

Honestly a game changer. I tell everyone to get one, really simple little product but makes such a difference when the weather turns colder

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Electric Heat Fermentation Box — USB + Foldable