Mark and I just looked at each other in disbelief. We had just cut into this steak cooked on our first grill prototype, and it looked just like it had came out of a sous vide water bath.

“This is tender for flat iron,” said a colleague, trying a bite. Mark had to agree. I had never tasted flat iron but that was the only steak left at the little market near my apartment. That moment was the first time we knew that we were onto something.

We had just proved that precision cooking was possible without using a water bath. This was the first time in the world that anyone had achieved that high level of food quality with an electric grill. Everyone knows how to use an electric grill: you just turn it on and throw on your food. And the potential to bring this new cooking technique, and the wonderful food it makes, to the world unfolded before us. It was quite a day, and we celebrated — by eating that delicious steak.

It all started with sous vide at a fine restaurant…

At a fine restaurant, I had that low temperature salmon that melts in your mouth and is like nothing you’ve ever tasted. It’s not sushi, it is cooked, but it’s not cooked like in a traditional restaurant, either. It’s just this amazing masterpiece. I asked them how it was made and they said sous vide. As I read more about it, I discovered sous vide could be used for many things, like steak, and started cooking that way on a daily basis.

Sous vide — perhaps the most common method of precision cooking — literally means “under vacuum” and consists of putting food into a plastic bag and cooking it in a pot of water.(1) There are some advantages to bagging as well, for example during long cooks the moisture is retained. And it was really the only way to make this incredible food.(2) But over time, I found that I started using it less, though I wanted to eat the food just as much. These are the kinds of difficulties that I experienced:

• Cooking with plastic bags in water is challenging. It’s hard to use liquid marinades, bags often float, and food is not accessible. During long cooks water evaporates and must be refilled. There are waste and health concerns.
• It can take a long time. Simply pre-heating a giant pot of water can take 20–40 minutes and a safety buffer is often added to the cooking time.
• Searing must be done elsewhere, since the maximum temperature is limited by the boiling point of water. This adds to cleanup, counter space, and planning.

So we set out to find a better way for daily gourmet. Not to replace sous vide entirely, which is so great for 72 hour ribs or custards. But to make it easy to cook great food at home after a long day at work.

But a grill doesn’t use water!

In our search for alternatives to sous vide, we settled on the electric grill because of its simple design and ability to fit the contour of a piece of meat.

Back to that sunny day in San Diego, when we put our theory to the test. We took our basic electric grill and ripped it open. It’s a simple design, essentially based around toggling an on/off switch connected to a heating coil. It’s either at full power or no power; we rigged it up so we could control it ourselves. Next, we set up two thermometers — one measuring the center of the flatiron steak, and one placed between the food and the grill to measure the cooking surface.

Then we switched the power on. As the cooking surface neared 136° we switched it off. As it cooled towards 134°, we switched it back on. We did this every second or so for two hours. Tedious, yes, but the results were beyond expectations — perfectly even doneness, from side to side.

As we explored this concept more, we found that a precision grill would solve each problem mentioned above:

• Since there are no bags or water the food is accessible, there’s less maintenance during cooking, and you’re not cooking in plastic.
• It’s faster because we don’t have a giant pot of water to pre-heat and we could get an accurate cooking time estimate by automatically measuring thickness.
• The ability to sear means one device can perform the full cook. That makes cleanup easier and requires less counter space.

So that’s how the idea for Cinder came about. We hope you can experience the amazing food for yourself. Thanks for reading — let me know your comments below.

(1) Why is sous vide done this way? Well the first use of sous vide was to minimize the evaporation of a very expensive food (foie gras) so it was bagged. Equipment to heat water precisely was available for other uses.

(2) Why not just use an oven? The thermal transfer of air is too slow. The food will spoil before it reaches the proper temperature.

That looks like sous vide steak! was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

Prep Time: 50 minutes, Cook Time: 35 Minutes

This week we asked ourselves, “What meal could we completely make on Cinder?” As someone practically raised on Mexican food, the answer was obvious — steak fajitas!

As a meal that is based on perfectly cooked steak, peppers, and onions, we knew this would be a simple, fast dish that could be easily replicated on those nights you’re too busy to throw together a fancy meal like our Scallop and Mushroom Risotto from last week.

Ingredients

• 1–1.5 lb Skirt Steak
• 3/4 Cup Olive Oil
• 2 Clove garlic, minced
• 1/2 tsp of fish sauce
• 1 Tbsp Soy Sauce
• 1 Tbsp Malt Vinegar (red wine or cider vinegar also work)
• 1 Red Pepper, sliced
• 1 Poblano Pepper, sliced
• 1 Red Onion, sliced
• Guacamole
• Salsa
• Black Beans
• Safflower or Avocado oil (not needed, but helps when searing)
• 6–10 Small Corn Tortillas
• 4oz Cheddar Cheese

1: Marinate and Cook the Steak

Combine olive oil, garlic, fish sauce, and soy sauce into a mixing bowl and whisk vigorously. Add skirt steak, top with a few generous cracks of pepper and marinade for at least 45 minutes.

Add your steak to Cinder and select Steak > Medium (131℉), Skirt steak is a bit thinner than most cuts, so expect this to take between 20–30 minutes to cook.

Once Cinder reads “done”, remove steak and set aside.

2: Sauté and Sear

Increase heat to 350 ℉— add olive oil, and sauté peppers and onions. Let them cook for 5–6 minutes, until they begin to brown.

Remove the peppers and onions and set aside. Increase heat on Cinder to 450℉.

Tip: If you have safflower or avocado oil, drizzle a bit onto your steak — it’s higher “smoke point” will result in a more even sear.

Once heated, add skirt steak and sear for 30 seconds. Remove steak and cut into thin slices.

3: Plating

Turn off Cinder. As it cools down, add the corn tortillas for a few 10–15 seconds to heat them up. Remove from Cinder. Combine steak, peppers and onions, black beans, guacamole and salsa on to top of a heated tortilla.

Garnish with cilantro.

Enjoy!

Cinder Precision Grill

Skirt Steak Fajitas, Precision Cooked was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

This week, we decided to see how Cinder can handle one of the more difficult seafoods to cook in the kitchen — scallops! As a seafood with a delicate texture and light flavor, it can be very easy to miss the optimal temperature range of 120–125℉. Scallops are especially difficult because they contain a lot of water and are very sensitive, so it’s easy to overcook and serve a rubbery, unappetizing dish.

In this recipe, the scallops were served with a mushroom risotto and precision cooked asparagus. This recipe calls for roasted garlic cloves and clarified butter, which may take as much as 45 minutes to make, so ensure you have these prepared prior to cooking.

Ingredients

• 0.5 lb Sea scallops,(or more, depending on your appetite!) at room temperature
• 6 cloves roasted garlic: Cut the top of a bulb of garlic and add salt, pepper and olive oil generously. Wrap in parchment paper and roast on Cinder at 350°F for 45 min
• 8 oz Asparagus — about 12 Spears, soaked for 30 minutes in 2 tbspolive oil, 1 tbsp of white vinegar, salt and pepper
• 1 small shallot, diced
• 1 cup crimini mushrooms, sliced
• 1 cup chanterelles, sliced
• 1/2 cup parmesan, finely grated
• 3 cups chicken stock
• 1 cup Arborio rice, soaked for 30 min in room-temperature water
• Sea salt
• Freshly cracked black pepper
• 1 tbsp freshly cut parsley
• 3 tbsp clarified butter — this is a key ingredient for cooking the scallops. Learn how to make clarified butter.

Cooking the risotto — 20 minutes

• Bring Chicken stock to a boil in small sauce pan and reduce to just barely simmering
• Meanwhile, turn on Cinder to 400℉, add 1/2 tbsp of clarified butter
• Once heated, add mushrooms and sauté, until mushrooms are golden brown, about 5 minutes. Set aside

• In a separate cast iron skillet, add shallots, Arborio rice (strain the water out after soaking), roasted garlic and 1/2 tbsp clarified butter, stirring gently until the rice begins to brown, about 5 minutes
• Once browned, begin adding the chicken stock 1/2 cup at a time, stirring constantly. Once absorbed, add another 1/2 cup. Do this for 2.5 cups or until completely cooked through, about 10-15 minutes. Taste a bit of the Risotto as it cooks to check if its done.
• Once risotto is cooked, turn to low heat, add mushrooms with 1 tsp of sea salt and a few generous cracks of black pepper. Stir until fully mixed in. If risotto begins to clump, add small (a couple tablespoons) amount of remaining chicken stock and stir.
• Turn burner to its lowest setting, and begin sprinkling in parmesan one pinch at a time. Stir constantly and continue adding parmesan until it begins to become slightly stringy. Remove from heat and cover to keep warm.

Cooking the asparagus — 5 minutes

• Heat Cinder to 425℉, add 1 tbsp clarified butter
• Lay asparagus flat across Cinder on an even layer, sprinkle with a pinch of sea salt.
• Close and cook for 5 minutes
• Remove and set aside

Cooking the scallops — 2 minutes

• Once at room temperature, pat scallops dry with a paper towel and lightly add a pinch of sea salt on both sides.
• Heat Cinder to 425℉ and add 1 tbsp of clarified butter.
• Add Scallops one by one to the Cinder and cook until the bottom edge has a 1/4 inch brown crust, about 45 seconds. Flip each scallop in the order they were placed, repeat for second side. The scallops should have a golden brown crust covering the top, as pictured.

Plating

Plate the scallops and add risotto and asparagus in a neat pile next to the scallops and serve immediately. Pairs well with a glass of Sauvignon blanc.

Cinder Precision Grill

Sea Scallops with Mushroom Risotto and Precision Cooked Asparagus was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

Burgers may seem simple, but getting it just right on a propane or charcoal grill requires attention. As a piece of meat that is hand-packed, the density of each patty can vary dramatically, leading one to cook faster than the other. Some may be too bloody, some may be burned to a crisp. It’s all a guessing game on a blazing hot barbecue.

With Cinder I don’t have to guess; all I have to do is select the doneness desired in the app. This will cook the burger to an exact temperature from surface to core, and hold it at that temperature until I’m ready to eat. After finishing with a quick sear to add proper grilled color, flavor, and texture, you’ve got a burger worthy of a five-star restaurant.

Ingredients

Hamburger:

1. 1.5–2 lb. Ground Beef
2. 1/2 Cup Worcestershire Sauce
3. Salt and Pepper, to taste
4. 4 sets of Hamburger Buns

Toppings and Fry Sauce:

1. 1 tomato, thinly sliced
2. 200g Sharp Cheddar Cheese
3. 1/4 Red Onion, thinly sliced
4. 1 Tbsp unsalted Butter
5. 2 Tsp Cane Sugar
6. 4 Eggs
7. 1/2 Cup Mayonnaise
8. 1 Tbsp. Ketchup
9. 1 Tbsp. Mustard
10. 1 Tbsp. Pickle Juice
11. Pinch of Cayenne Pepper

Part One: Prepare and Set Hamburgers to Cook

• Empty ground beef into a mixing bowl, add pepper and Worcestershire sauce generously and mix — do not add salt at this point.

• Form beef into four large patties, about 3 inches wide and 1 inch thick. Generously salt patties on all sides.
• Place in Cinder, close and in the Cinder App select Hamburgers: Medium doneness.

Cinder will heat your burgers to exactly 145℉, and maintain it at that temperature once it’s ready.

In the meantime, you can get back to enjoying the game.

Part Two: Prepare Toppings and Fry Sauce

While Cinder cooks your Hamburger patties, prepare the following:

• Caramelized onions: Place red onions and butter in a small non-stick skillet on medium high heat. Cook until onions are fragrant and beginning to brown. Then, sprinkle 1 Tsp of cane sugar over the onions and stir, allowing sugar to combine with butter. Once browned, keep warm until you’re ready to add it to your burger.
• Fry Sauce: Combine Mayo, Ketchup, Mustard, Pickle Juice, Cayenne Pepper and sugar into a small container and whisk until thoroughly mixed
• Fried Egg: To get a picture perfect fried egg, crack each egg individually into a small colander, allowing the lose yolk to separate from the egg. Place onto a skillet coated in canola oil on high. As egg cooks, scoop small bits of hot oil into a spoon and drizzle over egg to ensure it is fully cooked.

Tip: The caramelized onions and fried egg are best served immediately on top of your burger. To ensure all your ingredients are ready at the same time, wait until your Cinder reads done to start cooking. Cinder will hold your burgers at temperature until you’re ready to sear.

Part Three: Searing and Plating

Once your Cinder reads “Done” on the screen, remove the hamburgers with a plastic spatula and guide most of the grease into the drip pan. Turn the Cinder’s knob into “Sear” mode.

Once heated, place each patty individually onto the Cinder and sear for 30–40 Seconds. Remove immediately and place onto a toasted bun. Top with cheese, then egg and caramelized onions — the egg will help melt the cheese into the hamburger. Repeat for remaining hamburgers.

Add remaining toppings and serve. Best served with salad, baked beans, or french fries. Enjoy!

*This fry sauce recipe is from one of the Cinder team’s favorite cookbooks, The Food Lab.

Cinder Precision Grill

Football Sunday Burgers with Fry Sauce was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

Ingredients:

Biryani Rice:

• 3/4 Tsp Coriander
• 1/2 Tsp Cumin
• 1/4 Tsp Cardamom
• 1/4 Tsp Turmeric
• 1 Cup Chicken Broth
• 2 Tbsp Olive Oil
• 3/4 Cup Basmati Rice, washed thoroughly

Brussel Sprouts, Tomatoes and Almonds:

• 4 1/2 tbsp Unsalted Butter
• 1 Small Shallot, thinly sliced
• 1 cup chicken broth
• 1/2 Cup dry white wine
• 7 OZ (200 Grams) Brussel Sprouts, trimmed and leaves separated
• 1 Medium tomato, cored, seeded, and chopped
• 1/2 Cup almonds, coarsely chopped

Sole:

• 4 Sole Filets (between 1/2–3/4 Lb total)
• 1 Sprig Tarragon
• Sea Salt
• Freshly ground pepper
• All Purpose Flour
• 2 tbsp olive oil

This easy recipe has three parts to it:

1. Slow Cooking — Starting the Biryani in a rice cooker and Sole in your Cinder (20 Minutes)
2. Side Dish: Cooking Wilted Brussel Sprouts, Tomato, and Almond, with wine, butter and shallots, similar to a piccata sauce (12 Minutes)
3. Sear and Plating: Finishing your Sole with a quick sear on Cinder

Slow Cooking

Biryani Rice

1. Combine rice, Chicken broth, and spices in the rice cooker, stir
2. Press Cook
3. Once finished cooking, keep warm until remainder of meal is ready; add olive oil and stir before serving to prevent sticking
4. Sole

1. Wash over sole with cold water and pat dry
2. Add salt and pepper to taste
3. Coat sole lightly in all purpose flour
4. Place in Cinder and set to “flaky” in app (120F if using manually)– depending on the thickness of your Sole, this will take between 15–25 minutes.
5. Once Cinder reads “Done”, move onto cooking the side dish. Cinder will keep your Sole at the exact temperature until you’re ready to sear it.

Side Dish

1. Melt 1/2 Tablespoon of butter in a sauté pan over medium-low heat.
2. Add shallot and sauce until soft, about 2 minutes
3. Add stock and wine, increasing heat to medium-high, bringing to a boil.
4. Simmer until volume is reduced by half, about 10 minutes.
5. Drain the sauce through a strainer into a saucepan, Return the sauce to sauté pan at medium-low heat
6. Add 2tbsp of butter and whisk at low heat — don’t let the butter boil or it will separate with the sauce
7. Add Brussel Sprouts, tomatoes, almonds and tarragon and gently cook until leaves are slightly wilted, 2 to 3 minutes.

Sear and Plating

1. Remove Sole from Cinder, increase heat to 350F — typically Cinder’s sear setting is 464F, but this would cause the butter to burn. Stick with 350F.
2. Place Sole back on Cinder for 30 seconds. This should be enough time to add a crispy, golden brown coating
3. Combine Rice, Side Dish, and Sole into one dish. Makes 3 servings.

This dish was derived from two recipes — one Sole recipe from Kinfolk Magazine #14 and another Biryani rice recipe from Carla Snyder’s wonderful cookbook 1 Pan, 2 Plates.

Sole and Vegetables over Biryani Rice was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

We set our Cinder to 300F, and put on the bacon. We didn’t really know what to expect, so we decided to try a piece every 5 minutes.

The plan didn’t last 5 minutes. We took a look and everyone judged it not cooked enough, so we didn’t try it.

At 10 minutes, things were looking up. This was delicious! It was definitely chewy, but not tough. There were little bits of crispiness to it too. Everyone liked it, even the crunchy bacon fanatics. If you don’t know someone’s preference, this would be a good place to start. Only one of us selected it as the best, though.

At 15 minutes, it’s starting to develop a bit more crispiness, but it’s still chewy enough for our chewy bacon die-hard. One of us selected this as the best of the lot.

20 minutes in. No one selected this as their favorite, mostly because it wasn’t crispy or chewy enough for anyone.

At 25 minutes, it was now crispy enough for our crunchy bacon fans. Surprisingly, the chewy bacon fans still found it edible. It wasn’t dried out at all. Cinder brings peace and harmony to the world again!

Tragically, this is where we ran out of bacon. We ran to the store, reloaded the Cinder and continued…

30 minutes in was our crunchy bacon ideal: both crunchy bacon lovers picked this as their favorite. It has a satisfying crunch, but is still not at all dry. Having found everyone’s bacon number, we moved to 10 minute intervals.

At 40 minutes, it was very crunchy. One of us said that this would have been his preference if he hadn’t tried the 30 minute result.

At 50 minutes, the bacon is starting to dry out, and shatters when you cut it. One of our crunchy bacon fans was OK with it, but for the most part we weren’t fans.

At 60 minutes, it was pretty similar to 50 in crunchiness. The fatty areas are starting to have a puffy mouthfeel, like cheese puffs. There’s also a hint of bitterness coming into the flavor profile.

Sharp-eyed readers may notice that there’s a piece of bacon missing. Don’t worry, we don’t have a bacon thief. Our chef (names shall not be named) got a little excited and pulled the piece off before the picture was taken. Bacon is powerful stuff.

At 70 minutes, the bacon was extremely dry. Not a great texture. However, Eric noted that there was some complexity coming into the flavor here, “like an aged wine.” Perhaps some more exploration is necessary? Or maybe he was just trying to sound sophisticated.

Next: We seem to have found a good time range, so next we want to play with temperatures. Also, our friends at ChefSteps seem to think an extra long, low-temperature cook gives a particularly good flavor, so we’ll try that, too.

Do You Know Your Bacon Number? was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

We made smooth and tasty chocolate strawberries using Cinder to temper the chocolate, a complicated process candy-makers use to make liquid chocolate which cools as a beautiful shell. Read on for more thoughts and the recipe….

Candy is one of those advanced areas of cooking that I’ve never felt comfortable trying. On one hand, it requires extreme precision — slight variations in cooking temperature can produce greatly different results. On the other, it’s not forgiving if you cook it too far; burnt sugar is inedible, a cleaning nightmare, and will probably fill your kitchen with smoke.

Luckily, this is exactly the type of challenge that we envisioned Cinder solving. So when Shenzhen Valley Ventures asked us to do some appetizers for their hardware event, we decided it was the perfect opportunity to have a little fun and finally put chocolate making to the test.

Although this was our first time making chocolate, the process was easy and the final outcome was delicious. Other than having a little fun with the chocolate, I had a normal work day. Which is kind of awesome; I doubt I could have done so if I had to temper chocolate with a more traditional method. Cinder made a difficult technique incredibly easy. For me, cooking (and especially eating!) is far more fun when you take away the risk of ruining food and are practically guaranteed good results. That way you can focus on things like presentation or grabbing napkins.

Comparison to traditional cooking process

One of the people who tried a Cinder strawberry was a Ph.D. I quickly realized that she had tempered chocolate before, so I asked her about the process:

• it’s very hard!
• you have to cool the chocolate quickly, and there are two ways: a) use a cold marble slab, or b) only do half the chocolate, or do the other half
• it’s very easy to burn the chocolate

It took some deft words to explain that I had the exact opposite experience: it was easy on the first time, I didn’t have to do anything special for cooling, and I never had a single worry about burning it.

Recipe

This recipe results in smooth, tempered chocolate which can be used as coating for strawberries (or cherries or truffles), that solidifies into a great shell.

Cooking Steps — Overview

1. Heat to 115°F — set temp on Cinder, place chocolate on Cinder and close lid, give it around an hour.
2. Cool to 81°F — set temp on Cinder, open lid and put chocolate to the side, give it around an hour.
3. Heat to 92°F — set temp on Cinder, place chocolate on Cinder and close lid, give it around thirty minutes.
4. Put the chocolate in a dipping bowl and dip the strawberries.
5. Chill in freezer for 15 minutes.
6. Serve and eat!

(Or use the app to guide you through.)

Cooking Steps — Detailed

Buy a bag of chocolate chips and some strawberries (Costco in our case)

Pour chips into a Foodsaver bag and vacuum seal (if you don’t have a vacuum sealer a high-quality bag should be fine, like a zip-lock freezer bag).

Put bag on Cinder and close, heat to 115°F: this was a thick bag so I went back to work and came back about an hour later and it was at temperature — to check I agitated the bag and used the IR gun. The thicker the bag, the longer it takes heat to permeate; if you are in a rush and not using much chocolate, it might be ready in as fast as fifteen minutes.

That said, increasing the hold time may get better results. Ali Bouzari, a Ph.D. food scientist who did his thesis on sous vide time and temperatures, suggested that next time I wait longer since “The shifts in crystal structure happen gradually, so [by]…holding the chocolate at these key temperatures somewhat longer… you might get even better results in the future.”

Cool to 81°F: this part takes the longest — let it cool about 45 minutes and it had only to about 100F so I took the bag off and opened Cinder which sped things up. It was about another hour and the whole bag got to 81F or so. Sure, you could speed this up with an ice bath if you wanted but I had time and prefer to avoid hassle.

Note the current firmware limits the minimum temperature to 86°F; we will extend the range to at least 81°F based on this recipe.

Place the chocolate back in Cinder and cook to 92°F; about 20 minutes later when I came back at 6:26pm it was ready (the event started at 6:30pm).

Cut one corner of the bag to use like a piping bag, or fill a bin for dipping.

Put the chocolate on the strawberries, them chill them a bit to set the chocolate — otherwise it’s a gooey mess every time you try to eat one!

Serve and enjoy!

Thoughts for next time:

1. Use parchment paper or silicone pad for cooling, otherwise when setting the strawberries or they get really stuck to the plate!
2. As the chocolate cools it becomes harder to spread evenly on the strawberries, so make less chocolate or make all the strawberries at once before freezing. (Because this was an event I was doing one plate at a time.)
3. Try holding longer at each step per Ali Bouzari’s recommendation “you might look into holding the chocolate at these key temperatures somewhat longer… The shifts in crystal structure happen gradually, even at the target temperatures, so while it looks like the recipe worked out fine on this go round, you might get even better results in the future”

Stay up to date:

• Subscribe to our mailing list by clicking this link.
• Order your Cinder Precision Cooker (as of writing, an order placed today is expected to ship in November due to production waiting list).

Acknowledgements:

Recipe based on: Food Lab/J Kenji Lopez-Alt/Best Way to Temper Chocolate/Method#3: Sous Vide

Thanks to: Natasha Baker, Peter Berkowitz, Ali Bouzari, Kyle Connaughton, Travis Levell, J. Kenji Lopez-Alt, Max Mullen, John Tan, and Mark Wachtler for reading drafts of this.

Chocolate Strawberries at the Office was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

Design Lock-Down

We’ve finalized the design of Cinder and verified the design meets our performance expectations. Since our last update, we’ve accomplished the following:

• CAD work implementing fixes of problems we saw in testing the last round of prototypes.
• Built and assembled our Design Validation Test (DVT) prototypes — photo above. These were the last prototypes that we will build before starting tooling for production.
• Initial testing of the DVT prototypes is complete, and more extensive testing is ongoing.
• DVT testing results show that we addressed the issues found in testing our previous EVT prototypes, and we are ready to move forward with production.

Followers of our social media accounts (Facebook, Instagram) will notice the increase in content recently. We are happy to report that we’re cooking almost every day (at the office) now that the schedule is a bit less hectic for the team, and the DVT prototypes are performing reliably.

Tooling Has Started

Tooling kickoff is the biggest milestone for most hardware projects. The building of molds and dies for custom parts is what enables mass production, but usually represents the biggest capital cost for a product (and this is certainly true for our product). Proceeding with tooling means the team feels that the biggest risks of the product have been addressed.

Amid finalizing the design, a lot of other work had to be done in parallel:

We’ve set up our supply chain

• Vendors that are building our tooling and producing our parts have been selected after our in-person vetting and quotation process.
• Manufacturing agreements have been drafted, negotiated, finalized, and signed.

We’ve started tooling

• The final design was approved after a number of “all-hands” meetings, where engineers from all of our suppliers gathered in the same meeting room to review the entire design. Only after receiving sign-off on the design of each part from all parties did we proceed with sending the 3D CAD files to tooling design.
• Tooling design has been reviewed and approved.
• Tooling fabrication is currently in-progress. This is the longest part of the tooling build process, as our tooling vendors are going through the time consuming process of carving away hardened steel, and then fine tuning it to the correct tolerances. (I’d be happy to write a separate blog post on this for those who are interested!)

The start date of our tooling build means our scheduled mass production date is later than originally estimated. However, we felt it was irresponsible to kick off tooling prematurely, as difference between fixing an issue before vs. after tooling can be 30 minutes vs. 1 week.

One example of a big change introduced at the DVT prototyping stage was additional silicone and rubber seals. The decisions and actions of that story is a post of its own, and we’ll be sharing it soon.

While tooling is underway, the Cinder team is keeping busy

We’ve planned to make the most of this relatively quiet phase of the project by focusing on:

• Building out and testing the smartphone application.
• Cooking tests and recipe development.
• Designing labels, logos, and other on-product graphics (for serial number tracking, batch information, etc).
• Instruction manual writing, submitting for review, and getting it ready for printing.
• Packaging design to ensure each unit will withstand the occasional knocks, bumps, drops and vibrations of transit. We will soon get this design reviewed by packaging and logistics experts.
• Continued reliability testing of the DVT prototypes to try to discover unforeseen issues as early as possible.

Looking ahead

From here on out, our focus will be on ramping the volume and minimizing production issues. In the coming months, we have two big builds/pre-productions to complete. The first is to verify the tooling was made properly, and the other is to train the assembly line. There will be a lot of other work going on at the same time to support these builds, but the biggest milestones include:

• Assembling the first units using tooled parts. (These units will be used for beta testing.)
• Making tooling modifications to address any fit/finish issues of the parts.
• Internal performance testing, to ensure the product is behaving the way we designed it and meets our reliability requirements.
• Certification testing, to ensure our product meets safety standards and other relevant regulations (such as FCC for our wireless signals).
• Design of jigs and fixtures to help streamline the final assembly process.
• Pilot production, where the assembly line gets trained to assemble our product .

As always, we thank everyone for their support and making this journey possible. We look forward to reaching mass production of this product and fulfilling the orders that our pre-order customers have been patiently awaiting.

Project Update — The Road to Tooling and Beyond was originally published in cinder blog on Medium, where people are continuing the conversation by highlighting and responding to this story.