The Sourdough Sidekick automates tedious baking tasks

Baking sourdough bread is a time-honored craft that depends on natural fermentation and wild yeast, not the predictable commercial varieties. So introducing a gadget into that process might seem contradictory. Yet the Sourdough Sidekick, backed and branded by King Arthur Baking Company, aims to automate the most tedious part of the process: starter management. It feeds your starter flour and water on a preset schedule, ensuring it’s ready exactly when you plan to bake, so you can focus on kneading, shaping, and the actual baking.

Like any single-purpose kitchen appliance, you need to be confident you’ll use it enough to justify both the price and the counter space. That’s especially true here, as several design quirks make the Sidekick frustrating unless you bake multiple times a week.

The Sourdough Sidekick is a collaboration between FirstBuild , GE Appliances’ innovation hub behind the viral Opal ice maker , and King Arthur Baking Company. It launched via a crowdfunding campaign in March 2025 and is now available directly from King Arthur for $179.99, though only in the US.

Operation is straightforward. You place a small amount of existing starter , 15 grams, or about a tablespoon , into the crock, then fill the two dispensers with flour and water. In Auto mode, you tell the Sidekick when you want to bake and how much starter your recipe needs. It then drip-feeds flour and water on a dynamic schedule that accounts for local temperature, mixing as it goes, so you end up with the right amount of starter at its peak activity when you need it.

Using simple white bread flour, this worked beautifully. I told the Sidekick I wanted to bake in a few days, left it alone, and returned to find a strong, healthy starter ready for a decent white loaf. If anything, my bread came out overproofed, suggesting the Sidekick produced a more active starter than I typically manage on my own.

Flour goes into the hopper on top, water into the detachable tank at the back, and a few buttons and a dial handle the controls. In Auto mode, you simply set a target date, time, and starter weight.

You don’t have to stick with white flour, but switching flours requires a few minutes of recalibration to account for different densities. It handled most whole wheat and rye flours fine, but when I tried a particularly coarse-milled rye flour from British miller Landrace for a dense Danish-style loaf, the resulting starter was too thick for the Sidekick to mix properly, leaving dry clumps and thin patches. The starter needed more water, but that required leaving the straightforward Auto mode.

Auto mode has other limitations. It only works with exactly 15 grams of starter initially, so you must weigh that out each time. More frustratingly, it imposes odd minimums on the starter it produces. Set a bake day a few days out, and it will make as little as 150 grams. But aim for four days or longer, and it insists on at least 400 grams , far more than I typically use for one loaf, leading to more discard than my manual feeding ever creates.

There’s no Auto maintenance mode. You must set a bake day within the next week. That’s great if you know when you’ll bake, but sometimes you just want to keep your starter alive without a specific plan. In that case, you either set an arbitrary date and accept some discard, or remove the crock, lid it, and refrigerate it for a few days.

The Sidekick offers two other modes: Ratio and Custom. While Auto feeds at a 1:1:1 ratio, Ratio mode gives you preset ratios and lets you set the starter seed amount and feeding frequency. The catch is that the ratios only vary the starter proportion relative to other ingredients. Ratio mode doesn’t allow unequal flour and water amounts for a thicker or thinner starter , exactly what I needed for my coarse rye.

For that, you need Custom mode. It lets you set the seed amount, feeding frequency, and exact flour and water quantities per feed. I used it to make a looser starter for my rye, thin enough for the Sidekick to mix properly, and you could create a custom maintenance mode with micro-feeds. FirstBuild also provides instructions for using Custom to start a starter from scratch , I had a healthy new one in four days , or revive a struggling one. However, neither Ratio nor Custom modes account for ambient temperature, so they won’t adjust the schedule for warm or cool conditions, and you’ll need to monitor your starter’s activity yourself.

When your starter is ready, the Sidekick displays a timer showing how long it’s been since the planned time. The resulting loaf was decent, with clear signs of starter activity.

The Sidekick isn’t really a smart home device. It has Wi-Fi and an app, but they’re easy to ignore. The app sends notifications when your starter is ready or discard needs removal, but the built-in screen does that too. The app also lets you check settings but not change them. There’s little reason to use it.

FirstBuild recommends cleaning the glass crock, lid, and paddle between every feeding cycle to prevent buildup. That makes sense, but the crock and lid aren’t dishwasher-safe, so you’ll wash them by hand. Less frequently, you should wash the water tank and flour hopper, though those can go in the dishwasher.

The Sidekick is also surprisingly noisy. By default, it stirs the starter every two hours with 30 seconds of loud whirring. In a kitchen, that’s probably fine, but in a small space like a studio apartment, it could become annoying.

I can’t see myself buying the Sourdough Sidekick, but that’s mostly about me. My kitchen is too small for single-purpose appliances (coffee machine excepted), and my fiancée is counting the days until she can reclaim counter space and silence the mixing sounds every two hours.

I also don’t bake enough to get the most out of it. I make one loaf a week at most, often less. I’d be constantly taking my starter in and out of the Sidekick, probably feeding it manually in the fridge between weeks, losing half the benefit.

But if I had a bigger kitchen and baked twice a week? I think I’d be happy to own a device that handles the one part of baking I don’t enjoy. And I suppose my partner would just have to make peace with the noise.