Fermenter on the desk, with the front door opened and some tempeh disks visible inside of it

Hackaday Prize 2022: An Easy-To-Build Fermenter For Tempeh

October 3, 2022 by Arya Voronova 18 Comments

[Maud Bausier] and [Antoine Jaunard] believe we should all know about tempeh — a traditional Indonesian food made out of legumes fermented with fungi. To simplify the process a bit: you get some soybeans, add a tempeh starter fungi culture to them, ferment them a while, and out comes the tempeh. It’s a great source of proteins that’s relatively easy to grow on your own. One catch, though — you do need a certain kind of climate to have it develop properly. This is why [Maud] and [Antoine] are bringing a tempeh fermenter design to this year’s Hackaday Prize.

This fermenter’s controller drives a heating element, which adheres to a pre-programmed fermentation cycle. It also has a fan for airflow and keeping the heat uniform.

The fermenter itself is a small desktop machine with a laser-cut case helped by some CNC-cut and 3D-printed parts, electronics being a simple custom PCB coupling a Pi Pico with widely-available modules. This is clearly a project for someone with access to hackerspace or fab lab resources, but of course, all of the files are on GitHub.

Once built, this design allows you to grow tempeh disks in home conditions on a small scale. It seems the design is mostly finalized, but if you’d like to hear news about this project, they have a blog and a Mastodon feed with some recent updates.

We’ve covered a whole lot of fermentation-related hacks over these years. Most of them have been alcohol-related, but every now and then we see people building fermentation equipment for other food materials, like vinegar, yogurt and sourdough. Now, having seen this fermenter, we’ve learned of one more food hacking direction to explore. This project is one of 10 finalists for our latest Hackaday Prize round, Climate-Resilient Communities. It’s a well-deserved win, and we can’t wait to see where it goes!

A hand holds a round disc of noodles wrapped in a translucent film with herb specs embedded in it.

Reimagined Ramen Comes In Edible Package

September 15, 2022 by Navarre Bartz 31 Comments

Hackers and college students alike reach for ramen when they want to fuel up on a budget, but, if you’re concerned about packaging waste, the plastic film and foil packets start to weigh on your conscience. [Holly Grounds] was sick of this compromise and came up with a way to have your packaging and eat it too.

[Holly] first experimented with different bioplastics until she developed a recipe for “an edible, tasteless starch-based bioplastic, that dissolves in contact with boiling water.” With that accomplished, she next integrated flavoring into the bioplastic wrapper so that there’s no foil packet. She found that herbs and spices worked, but larger solids like shrimp couldn’t be incorporated into the film.

For the finishing touch, she fashioned the noodles into a disk so they fit better in a bowl for cooking. To cook the noodles, you remove a puck from the wax paper sleeve holding multiple servings, add boiling water, stir, and enjoy. [Holly] says that her ramen packets are quicker to prepare than existing packets since there are fewer steps and the shape is optimized for cooking. That’s a win-win for the planet and convenience.

If you want to see another pasta packaging marvel, we’ve previously covered Flat Pack Pasta. Have your own project to reduce packaging waste? Submit it to the Save the World Wildcard round of the Hackaday Prize which closes on October 16th!

Your Car Gets Hot When Left In The Sun. Hot Enough To Cook?

September 8, 2022 by Jenny List 18 Comments

In hot weather, those of us who drive are familiar with the sensation of getting into the car and having it feel like an oven inside. A car is a essentially sealed metal box with large windows, thus on a sunny summer day it has more in common with a greenhouse, and in a heatwave this can become unbearable. But does it get hot enough for cooking? [Julian Lozos] aimed to find out, by cooking Icelandic rúgbrauð using only a 2016 Honda and the California sunshine.

Rúgbrauð is a traditional Icelandic rye bread that’s traditionally cooked by geothermal energy buried in the ground for around a day in proximity to a hot spring. A car dashboard gets pretty hot in a California heatwave, so it’s not unreasonable to expect that it might replicate this environment. He parked the Honda on a street in the sun, placed a pot full of dough on the dashboard, and waited.

The maximum temperature measured was 86.5 C (187 F), but unfortunately the sun didn’t stay high enough to maintain that temperature for the required time. After two days in the car the crust was cooked but the interior was still gooey, so the experiment can’t be said to have been successful. He does make the point though that a less traditional and much thinner loaf using a wide and flat tray might have delivered a better result.

We’re intrigued by this experiment, almost enough to try something like it ourselves were the summer not beginning to wane in these more northerly climes. Have any of you tried cooking in a hot car, or would we need a solar oven? Give us your views in the comments.

Robot Brutally Chops But Makes Poor Guacamole

September 2, 2022 by Lewin Day 27 Comments

Making guacamole by hand normally takes [Estefannie] about 9 minutes. Given her insatiable appetite for the delicious condiment, she spends a lot of time whipping it up in the kitchen at home. Thus, it’s a task ripe for automation, and she set about building a robot to do the job instead.

The robot starts by chopping ingredients like tomato, onion, and avocado with a knife that swivels to cover the entire chopping board surface. Once chopped, a sweeping blade pushes the ingredients into a bowl to form the guacamole.

Initial tests were messy, and ingredients were chopped a little inconsistently. Later work involved reprogramming the machine to chop ingredients separately, rather than all at once, which did improve the quality of the guacamole significantly. However, fundamentally, it wasn’t making good guac, so much as it was making a very chunky salad. It simply couldn’t do all the complicated jobs required to make a smooth, delicious dip.

[Estefannie] elected to instead let it live out its life as a mighty chopper, showing off its prowess by having it attack candy, cake, watermelon, and chocolate, which was pretty fun to watch. It bears noting that if you’re building a robot that swings a blade around, you need to be very careful. If you’re looking for something a bit safer, perhaps a Taco Bot is in your future.

Continue reading “Robot Brutally Chops But Makes Poor Guacamole” →

The Cheat Way To Perfectly Split An Oreo

August 31, 2022 by Lewin Day 28 Comments

Believe it or not, much research has been done in how to perfectly split Oreos with an even amount of cream on both sides. Early studies suggested it simply wasn’t possible, with one side always getting the majority of the cream. However, [Ian Charnas] has now found a sneaky workaround.

First attempts involved heating in a microwave or chilling the cookies in the freezer. Neither helped in the slightest. A vacuum chamber only served to delaminate the cream from both sides of the cookie entirely, while water jet cutting made an awful mess.

[Ian] ended up realizing that crack propagation could be used to prepare Oreos for a perfect split. A knife was used to score a groove all around the cream layer, right down the middle. The Oreos were then frozen, turning the cream effectively solid. When the Oreo is then twisted, the groove serves as a starting point for a crack that propagates across the surface, splitting the cream neatly between both halves.

[Ian] took things further by building a 3D-printed lathe that grooves Oreos using a sterilized scalpel blade. This allows cookies to be quickly prepped for a perfect split. However, you are left eating frozen Oreos at the end of it, with some sacrifices to freshness.

It’s a neat way to approach the Oreo splitting problem, even if it’s only one step removed from simply using a knife. We’ve seen [Ian]’s work before, too, in the form of the radioactively-powered Game Boy. Video after the break.

Continue reading “The Cheat Way To Perfectly Split An Oreo” →

Make Your Own Vinegar

August 26, 2022 by Danie Conradie 32 Comments

Making fermentation work for us is one of the original hacks that allowed humans to make food last longer, and festivities more interesting. [Mike G] has been experimenting with making his own vinegar, and found the end product to be a delicious addition to his cooking.

The first step is similar to making alcoholic beverages. Take something that contains sugar, like fruit, mix it with water and let stand. Wild yeast will feed on the sugar and create alcohol. Once the alcohol content reaches the 6-12% range, the resulting liquid can be separated from the solids and left exposed to the air. This allows Acetobacter bacteria to convert the alcohol into acetic acid, producing vinegar. The entire process takes around 30 days.

[Mike]’s first round of experiments was mainly with fresh fruit, with the addition of raisins. To prevent white mold from forming the mixtures should be stirred daily, but life got in the way and mold got out of control on all the fruits, except for the raisins. This gave [Mike] the to try another round with dried fruit, which was significantly less prone to mold, and produced deliciously flavored vinegar. [Mike] also demonstrated their use in a couple of mouth-watering dishes.

The DIY vinegar production process is just begging for some fermentation monitoring and automation tech. We’ve seen plenty of sourdough and beer production projects, which we suspect could also be applied to vinegar production with some minor changes.

Continue reading “Make Your Own Vinegar” →

An opened plastic project box with electronics inside

Smoking Meat Finds Natural Home In The Cloud

August 9, 2022 by Chris Wilkinson 15 Comments

Did you know that backyard barbecues now come with WiFi? It should be no surprise, given the pervasiveness of cloud-enabled appliances throughout the home. However [Carl] wasn’t ready to part with his reliable but oh-so-analog BBQ smoker, so instead he created an affordable WiFi-based temperature monitor that rivals its commercial counterparts.

Accurate temperature measurement is essential to smoking meat from both a taste and safety standpoint. In this project, two Maverick ET-732/733 thermistor probes take care of the actual temperature monitoring. One probe is skewered into meat itself, and the other measures the ambient ‘pit’ temperature. Combined, these two gauges ensure that the meat is smoked for exactly the right length of time. [Carl] mentions that adding an extra temperature sensor is trivial for larger setups, but he’s getting by just fine with two data points.

Naturally an ESP8266 does most of the heavy lifting in bridging the gap between smoke and cloud. At the core of this project is utility and practicality – temperature statistics can be viewed on any device with a web browser. Being able to study the temperature trends in this way also makes it easier to predict cooking times. Electronic alerts are also used to notify the chef if the temperature is too hot or cold (among other things). The entire contraption is housed in a smart looking project box that contains an LCD and rotary encoder for configuration.

If this has piqued your culinary interest, check out the extensive documentation recipe over on GitHub and the project Wiki. We also recommend checking out this project that takes automated meat smoking to the next level.