The Sourdough Sidekick uses a less fun recipe

Sourdough baking is old-fashioned, relying on natural fermentation and wild yeast instead of simple, obvious commercial products. So it might sound awkward to bring a weapon into the mix.

The trick of Sourdough Sidekick – supported and known by King Arthur’s flour – is that it promises to make sourdough baking easier: basic management. It feeds your starter flour and water on a regular schedule, ready for when you want to cook, leaving you to focus on scratching, making, and actually cooking.

As with any single-purpose kitchen appliance, you need to be confident that you’ll get enough use out of it to justify the price and counter space. It’s doubly true here because of a few tools that make the Sourdough Sidekick frustrating to use if you don’t bake a few times a week.

The Sourdough Sidekick is a collaboration project with FirstBuild – the GE Appliances “innovation hub” that oversees it viral Opal ice maker – it’s King Arthur Baking Company, which is why you’ll see the last logo on the front. They it was launched by a crowdfunding campaign in March 2025, but it’s now available to buy directly from King Arthur for $179.99 – though it’s US-only.

The basic function is pretty simple. You throw a small amount of starter into the crock – 15g, or about a tablespoon’s worth – and fill the two dispensers with flour and water. In Auto mode, you tell the Sidekick when you want to make the bread, and how many starters you want for your meal, and it skips flour and water in dynamic meetings that take into account your temperature, the mixture that goes, to finish with the right amount of starter, at the peak of its activity, when you need it.

Using plain white bread flour, this worked really well. I told the Sidekick that I wanted to bake in a few days, left it alone, and returned to find my powerful, healthy, and ready-to-bake beautiful white bread. If anything my bread came out unmixed, meaning that the Sidekick produced a stronger starter than I was aware of on my own.

You don’t have to use white powder, although every time you change powder, you should spend a few minutes resetting the Sidekick to count the different colors. It handles wheat and rye flour very well, although I tried dry rye flour from the British miller Landrace for green Danish rye breadthe primer was too thick for the Sidekick to blend in properly, leaving me with dry patches and thin patches. The starter needs more water to reach the right consistency, but for this I had to leave the easy Auto mode.

Auto mode has a few other limitations. It’s designed to work with exactly 15g of starter, so you’ll need to measure it regularly to get the right reading. More annoyingly, it has an odd limit to the number of initializations it will want to create. Set the cooking date for a few days and allow yourself to produce 150g, but prepare for four days or more and strive to produce at least 400g. That’s a lot more than I use for one loaf of bread, which results in a lot more waste (most of the ingredients you can’t use for baking) than if I feed by hand.

There is no way to set Sidekick in Auto repair mode. You to be set the cooking date, that’s it he is be within the next week. It’s best if you know what you’re going to cook soon and when. But sometimes I just want my starter alive and never know when I’ll need bread. In that case, you need to set the date that you want it to be needed and leave it to waste, or pull a large cord from the machine, open the lid, and put everything in the fridge for a few days.

The Sidekick has two other models, Ratio and Custom, which are slightly more versatile. While Auto feeds your starter with flour and water at a 1:1:1 ratio, the Ratio Mode gives you a number of options to choose from and allows you to set the amount of starter seed and feed rate. An odd limitation is that the parts that are installed differ only in the number of elements compared to other ingredients. The retio format doesn’t allow you to add uneven amounts of flour and water to create a base that’s thicker or thinner than usual – exactly what I need for my rye flour.

For that you need Custom mode. This allows you to choose the amount of seed, the amount of feed, and the amount of flour and water you need for each feed. I was able to use it to make a slightly thinner starter for my rye, thin enough for the Sidekick to mix happily, and it should be possible to use it to create a routine with small feeds. FirstBuild also offers instructions for using Custom to build a starter from scratch – I was able to get a new starter up and running in four days – or to restore one that’s on its last legs. Just be aware that neither Ratio nor Custom mode takes into account the current temperature, unlike Auto, so it won’t change the feeding schedule if it’s hot or cold, and you have to monitor how your starter is working.

Sidekick is not a smart home device. There is a Wi-Fi option and an app, but it’s easy to ignore. The app will send notifications when your launcher is ready to use or toss it should be removed, but the built-in screen does as well. Otherwise the app allows you to view Sidekick updates, but not change them. There is no good reason to use it.

FirstBuild recommends that you wash the glass, lid, and paddle between each feeding to prevent unwanted buildup. It makes sense, but the crock and lid are not dishwasher safe, so you have to wash them by hand. Little by little, you are advised to clean the water tank with a powder towel, but this can be thrown in the dishwasher.

The Sidekick also sounds amazing. By default, it vibrates the starter once every two hours, which includes 30 seconds of loud noise each time. Since it’s going to be in your kitchen, it’s probably fine, but in a small space like a studio apartment, it might get in the way.

I can’t see myself buying a Sourdough Sidekick, but that’s me. My kitchen is too small to justify single-use appliances (coffee machine excepted), and my boyfriend is counting down the days until he can find a counter and remove the mixer every two hours.

I don’t cook enough to take advantage of it either. I usually make one loaf of bread a week and usually less. I would be taking my starter out of the Sidekick more often, probably hand-feeding it between weeks in the freezer, and losing half of the benefits it had in the first place.

But what if I had a big kitchen and cooked twice a week? I think I would be happy to have a device that takes care of cooking that I don’t really care about. And I think my friend should just calm him down with the noise.

Photography by Dominic Preston/The Verge