Restoring an old, broken PacoJet 1

One of the pieces of equipment very high up on my bucket list was a PajoJet. It had stood there for years but the buying price, even for a used unit was just too prohibitive.
A new PacoJet will set you back over 4.500 Euro, even a used one is around 2.000 Euro, which is just a little steep for a private household.

For those who haven’t heard of it, a PacoJet is something like the holy grail for Michelin-star chefs to achieve perfect textures for Mousses, Ice Creams, sauces, etc.
So, when I was offered a broken unit that was deemed beyond salvage at a very low price, I thought “challenge accepted” and bought it.
Unfortunately, there aren’t any repair-manuals available. Also PacoJet won’t sell spare parts, so you have to go with what you can salvage. If one of the specific components like the mainboard or the power supply can’t be repaired, you’re stuck.
I do understand their point here though. The unit is rather complicated, computer controlled and involves high-speed components. Nothing you want your fingers caught in.
If you don’t know exactly what you’e doing, you’ll either get electrocuted or you’ll amputate a few fingers in the revolving mechanics.
This is definitely a case of “don’t do this at home”!
Having restored a few cars, I thought “well, it can’t be more complicated than that”. Unfortunately, it was.

Spoiler alert: In the end I managed and I learned a lot in the process but if I calculate all the hours I put into the restoration, this is probably the world’s most expensive PacoJet ever.

When the PacoJet arrived in the original carton and I unpacked it, I immediately understood why it was sold as broken and beyond salvage.
It was dented and scratched plus it was just dead, one light came on when I powered it up but nothing else.

The PacoJet as it looked when I unpacked it. Dented, scratched and lifeless.

So, in order to get to the ground of things, I opened the case and checked the mechanics.
I decided to take a step-by-step approach and to fix one issue after the other.
Opening it, I immediately saw that the unit was absolutely dirty and grimy.
A sticky layer of fat and dirt covered everything inside the unit.
Over 20 years in a restaurant-kitchen take their toll.

The inside of the device. Very dirty and grimy. Notice also the power-switch. This was broken and water could run inside the power-supply. A major safety issue and an accident waiting to happen.

One of the first things I noticed was that the security-switches for the beaker-holder were totally dirty and worn.
These switches ensure that the unit will only power up when a beaker-holder has been inserted properly. Otherwise only the green power light will come on but nothing else will happen.
This was exactly the behaviour the device showed, so I used an Ohm-Meter to check the switches and found one to be faulty.
I then bridged this switch to test if the unit would power up.

The faulty safety-switch with a bridge for testing if this was the cause if the error. Never run the system like this though!

Powering up the unit, the display came on immedately, the “ready”-light was green.
Before going on, I replaced both switches with new ones. Even though one was still ok, it was just a question of time when it would break as well. It’s always better to replace this kind of thing when the unit is open anyway.

The old safety-switches were replaced with brand new ones.

With the new switches in place I then tried to do a function-test of the device.
Unfortunately, it only sprang to life for a split second before going dark again.
Not what you want, but hey, that would have been too eas and nothing better than a good challenge.
I decided to continue my troubleshooting activities by checking the electronics.
All ciruit boards were extremely dirty and impossible to check.

A very, very dirty and sticky Circuit Board

Even with all the dirt on the boards, you could still see that some components were clearly faulty.
If you take a close look at the Siemens-component in the foreground on the picture below, you’ll notice that some of the legs are askew and seem to have been re-soldered after having broken off at some point.
Clearly, whoever had been tring to repair this unit in the past didn’t have a clue what the were doing.

The Siemens TLE4260 in the foreground: The legs were badly soldered on after having broken off and clearl didn’t have a proper contact.

I decided to bathe the circuit boards in alcohol to clean them. Even though this may not sound like a good idea, it actually works. After having bathed the mainboard in alcohol and having carefully removed the dirt with an old toothpaste, it actually looked like new.

Bathing the mainboard in alcohol actually made it look like new.

When I turned the mainboard over to check the rear, some components actually fell out.
These seem to have come loose at some point and were only held by the sticky fat and dirt that had crept everywhere.
The bent transistors on the picture below also caused issues and needed to be replaced.

After cleaning the mainboard, a transistor plus some other components just fell out. They had been held in place only by the dirt on the mainboard.

I decided to do a thorough check of the board to see if there were any other cold soldering points. I found a few.

The rear of the mainboard. The soldering points marked red were cold, i.e. the components werent’s soldered in properly, causing the unit to malfunction.

I decided to replace all components that looked slightly dodgy, especially the Siemens TLE 4260. I found a source that sells this component for less that 4 Euros, so I bought a handfull, in case I break one or it fails some time in the future.
The comparison between new and old is stunning.

The new TLE 4260 versus the old one. 4 missing legs that lost contact whenever the unit moved. No wonder it failed.

I also removed and tested all other transistors on the board. Checking them in a tester showed some of these to be faulty as well.

Removing, checking and replacing all transistors on the mainboard.

Having throroughly checked the electronics one more time I reassembled the unit and again tried to run it.
This time it actually ran, at least for a while.
Something was still wrong though.
Even though the control panel showed that the rotating rod inside the device, to which the blade is fastened, was supposed to move up again after having finished scraping the frozen contents of a beaker, it continued going down at a very low rate.
This pointed to a mechanical issue, so I needed to figure out the principle on which the device actually works.
Originally I thought this was something like a power drill, very simple and easy to understand. The more I learned though, the more I was impressed by the ingenuity of the machine.
Basically, the whole principle is based on the fact that the rod rotates inside an also rotating steel tube. The rod will always rotate in the same direction and at a constant speed of 2,000rpm while the speed of the tube will vary, depending on whether the rod is supposed to go up or down.
Whether it goes up or down and at which speed depends solely on the difference beween the speed of rod and tube.
If the tube rotates faster than the rod, the rod will move up.
If the tube rotates slower than the rod, the rod will move down.
While the rod rotates at a constand speed, the speed of the tube is controlled by a gearbox which contains two electromechanical clutches, one at the top and the other at the bottom.
Having determined that a mechanical issue was be the cause of this problem, I decided to test the gearbox by powering the clutches separately and to see if they engaged properly.
I quickly noticed that, even though both clutches made a loudly audible click when activated, the bottom clutch didn’t actually engage properly.
The top one seemed to move, at least a bit, but I wasn’t sure if it was ok, so I decided to disassemble the gearbox.

The gearbox. On the left and on the right, you can see the two electromechanical clutches

As can be seen in the picture, the gearbox -like everything else inside the unit- was extremely dirty. I therefore decided to clean all components thoroughly.
Especially the clutch on the left seems to have had contact with a liquid which definitely also ran inside the clutch.
Removing the clutches revealed even more dirt in and around them.

One of the two clutches. My hands were actually clean before I removed the parts. These clutches were extremely dirty.

As dirt is never a good thing inside a clutch, I checked if I could find spares online.
I actually found some used ones on eBay. These looked worse than mine though and were still supposed to cost 100 Euro each. As that wasn’t an option, I took the risk, disassembled my old ones, cleaned them until the inside looked like new and then reassembled them. Miraculously, no parts were left over.
Having cleaned and reassembled the gearbox I again tried actuating the clutches. This time they moved significantly stronger than before.

The disassembled gearbox with the equally disassembled top clutch.

I did actually manage to get the whole unit reassembled, redid the cabling of the mainboard, the top board, the power supply and all the sensors in the unit.
I also replaced the power switch to make the unit properly waterproof again.

Now the big moment: Trying if it works.
Power On, select 1 portion, hit “Start”.
Lots of noise, the rod goes down, stops briefly…. and goes up again!

Challenge mastered, goal achieved. The unit that had been declared beyond salvage actually worked.
Now… taking into consideration the dozens and dozens of hours I spent repairing it, even at minimum wage this repair would have been extremely expensive, so I guess it really was beyond salvage if you take into account the labour-costs.
On the other hand, I did this in my spare time, so in the end I got a fully functioning PacoJet for a low three-digit figure.

Now that it worked, I also wanted it to look nice and fit into the kitchen, so I decided to work on the metal case.
First of all, I removed the dents and sanded it down to also get rid of all the scratches.

The outer case after having filled in the dents and having sanded out the scratches.

I then sprayed it in a classic beige tone to give it the retro-look I wanted.
This way it will fit in with my other kitchen appliances.

The case with the first layer of beige paint.

The beige paint was then covered with two layers of high-gloss clear paint.
Finally, I used chrome-letters normally used in the Automotive Industry to put some finishing touches to that retro-look.

Adding a new Overlay for the display as well as chrome letters to the front gave the 25 year old PacoJet a classic look.

With all the work I put into it, the PacoJet now looks brand new and matches the other appliances nicely.

The “new” PacoJet among the other appliances in the kitchen.

Go Green: Creating Basil Cream with Xanthan Gum

Sometimes I find that just adding Basil to a dish is boring.
We can do better than that, so I decided to make some Basil Cream.
I didn’t want to heat the Basil as I needed it to keep its full flavour.
That’s why I used Xanthan (E415) to do the job.
First of all, take a lot of Basil. You can’t use too much. The more you take the more aroma you will get.
Then add some Olive Oil (I use 3 tablespoons for 100g of Basil) and some water (rule of thumb: 2/3 of the weight of the Basil, in this example: 66ml).

Now use a hand blender to blend thoroughly.
This will take some time. Basil will stick to the blades and you’ll need to remove them manually.
Whatever you do, don’t put your fingers between the blades! Always use a small spoon. If for some reason these blades start turning there won’t be enough left of your fingers to sew back on!

Once its’ well blended, strain the liquid through a sieve.
Use a spoon to press the liquid through the sieve. You want to get as much out as possible.
Once a dry, dark green crust remains in the sieve you can stop straining.

Now add 1% Xanthan Gum.
As the remaining liquid weighed 174g, I added 1,74g of Xanthan.
You need to be very precise here. Adding too much will make the cream too thick.

Use the hand blender to blend the liquid with the Xanthan Gum. Remember to clean the blender first as you don’t want any of the Basil Crumbs in your cream.

You can stop blending once the cream has reached a nice viscosity.
Now pour into a squeeze bottle.

This cream goes very well with tomatoes.
You can use it to create something like “Caprese Moleculare”.
I do this by placing Mozzarella di Bufala at the bottom, followed by Mozzarella Cream and diced tomatoes.
On top comes the Basil Cream. This adds a great aroma and perfect colour.

Xanthan Gum: Magic for Sauces and Pastes

For some sauces and liquids, Xanthan Gum is the way to go.
Stirring it into a cold liquid will significantly increase the viscosity of this liquid, turning it into a cream or paste.
You will probably consume more Xanthan in everyday life than you’re even aware of. Just check the packaging of your toothpaste, cosmetics, ice cream,salad dressings, sauces.
Gluten free foods are also highly likely to contain Xanthan Gum as it gives them the stickiness that normally comes from Gluten.
If it says “E415” on the package, it contains Xanthan Gum.

The great advantage is that Xanthan Gum doesn’t change the flavor or the colour of the foods that are treated with it.
I personally use it a lot in my cooking.

One great example is soy sauce. Soy Sauce has a very low viscosity. Iyou pour it over food it will just run down and collect at the bottom of the plate. Not what you want if your dish is artfully stacked or it simply needs to stick to your food to get the full flavour.
Of course you could simmer down the soy sauce until it has the required viscosity. This will take a long time though and, what’s worse, the result will taste extremely salty. Trust me, I’ve been there.

Instead, all you do is add a little bit of Xanthan Gum, stir hard using a hand blender or, in case of small quantities, a milk frother. You’ll find that while you stir, it gains viscosity and starts turning into a perfect soy cream.

Start with 0,5% and work yourself up in steps of 0,1% until your cream has reached the desired viscosity.
So, if you have 100g of Soy Sauce, add 0,5g of Xanthan. Stir for a while and check the viscosity.
If you aren’t satisfied with the result, add 0,1g and continue stirring. And so on. Don’t go too high though. Be patient when you stir. It takes a bit of time for the effect to kick in.
For a perfect viscosity I find that 1% is sufficient for most pastes.

The absolute limit should be 2%, i.e. a max. of 2g Xanthan Gum on 100g of Liquid.
This is still far below the limit where it would act as a laxative.

Please make sure to use an extremely fine scale. Just remember that you apply Xanthan Gum in steps of 0,1g. If you are just 0,05g off, that would be 50%!
Your scale should therefore be precise to a hundredth of a gram.

When you’re done you can fill the cream into a squeeze bottle. This can be used for storing your cream in the fridge for a few days and makes it really easy to apply it to your meal.

Another good example is Balsamico Vinegar.
I’m sure you know these “Balsamico Creams” you can buy in the shops. Guess what…if you’re lucky, they’re only 40% sugar, often more.
Check out this example of a Balsamico Cream I found in Italy. Granted, it’s cheap. But 41% sugar and 277 calories per 100g, really?

I covered the name of the manufacturer as it doesn’t really matter. Basically they are all the same.

Do yourself a favour. Buy a proper Balsamico di Modena, add a little Xanthan Gum (0,5%…, raise percentage as described above) instead of this convenience-stuff.

Look at the picture below.
This real Balsamico has only 84 calories/100g and 15% sugar, i.e. a third of the ready made cream.

So, here is how it’s done.

What we need:
– Balsamico
– Xanthan Gum
– Fine Scale (1/100th gram)
– Milk Frother
– Squeeze Bottle

First of all, weigh the Balsamico you’re going to use. In my example this is 50g.

Now add 0,2g of Xanthan Gum by sprinkling it delicately over the Balsamico.
Xanthan Gum tends to form lumps. The looser you sprinkle it the less lumps you will have.

Add Xanthan Gum in steps of 0,1g and use a milk frother to stir it into the Balsamico until the viscosity is right.

After some time you will notice that the viscosity of the Balsamico increases.

When you’re done and the creaminess is right, fill it into a squeeze bottle. Also, try it.
Yes, it’s much less sweet than one of those ready made Balsamico Creams. But hey, it’s vinegar.
It’s supposed to taste like vinegar.
This is the real thing.
On the picture you can actually see the viscosity of this Balsamico.

Now use the Squeeze bottle to apply it to your dish. Because of the viscosity you can achieve great effects here.

Seriously Overrated: The Juicer

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I think one of the most overrated tools in the kitchen is the juicer.
If you own one, how often do you really use it? And what do you do with it?
Mine (which you see on the photo) is now over one year old and I’ve used it maybe two or three times.
All I use it for is juicing tomatoes. I haven’t used it for anything else yet.
When I bought it I thought “Wow, a juicer! I’m going to do so many cool things with it.”
After using it for the first time, when I had to clean it, which was a hassle and really time consuming, I though “Wow, what a freaking lot of work, just for a few juiced tomatoes.”.
In the end, I didn’t even find any recipes where I needed so much fresh juice that it was worthwhile using it.
In 99% of the cases, I find it easier just cutting stuff up and straining it through a cloth. This takes a bit of time and is quite a lot of work but in the end still less time consuming than having to clean a juicer.
For juicing tomatoes though, it’s brilliant.
A lot of my recipes from the Molecular Cuisine contain tomato-water.
Even though tomatoes are red, tomato-water is actually yellow, at least of you manage to get out all the meat, skin, etc. This really works best with a juicer.
The yellow tomato-water has a very intensive tomato-flavor.
You can easily turn it into a foam with Lecithin, make tomato gummi-bears using Agar Agar, create tomato spheres, etc.
That’s another story though. But anyway, that’s the only use I’ve found for my Juicer so far.
If you have any other uses, please leave a comment.

Molecular’s Little Helpers: Dosage

When I searched for a comprehensive list of dosage-recommendations for my most important molecular ingredients, I was disappointed to find nothing proper on the web.

Based on my experience, I created my own.
I listed only ingredients that I use myself, the most important being Agar Agar, Xanthan Gum and Lecithin (in that order).
The rest… well, I have them, but I don’t use them that often.
One of them. Methyl Cellulose, I don’t use at all anymore. Basically this is wallpaper glue. Also, it’s used in the adult film-industry for fake… oh well, I leave this to your imagination.
But whatever, it’s something I don’t want in my food. I have listed it because many recipes still contain it. But if possible, you should refrain from using it.

The quantities shown here are always min. -> max. What within this range is right for whatever you’re doing depends on several factors, e.g. how much acid your liquid contains, whether it contains alcohol, etc.
It may take a few tries to achieve a satisfactory result.
My approach is to start in the middle and then go up or down, depending on whether the result is too hard or too soft.

Please note that some of these additives can have side-effects. Even though they have been tested to be fit for human consumption (shown by the ‘E’-Number), the tests were done with certain maximum quantities.
You should keep the quantities you use as low as possible, even if you should find recipes that require high quantities.
I’ve found recipes that go way above the maximum permitted quantity for industrially produced food.
If in doubt, rather don’t do it.
Sticking to the max. quantities shown in the list above should keep you on the safe side but in case of doubt, please check.

Molecular’s Little Helpers: The Most Important Additives

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Molecular cuisine relies heavily on additives, some of which are vegan and actually quite helpful, while others… I’ll never understand why people put some of this stuff into their food.

There are of course a lot more than listed here, but these are the ones I regard as most important (as I use them a lot).
Others may have a different opinion but that doesn’t mean they’re right and I’m wrong. 🙂

I don’t list them alphabetically here, but rather in the order of their importance for my own cooking.
For a quick overview on the dosage, please check here:
Molecular’s Little Helpers: Dosage

Agar Agar (E406):
Used for Gelification.
Agar Agar is believed to have been discovered in Japan in the mid 17th century. It’s obtained from Red Marine Algae, making it a vegan alternative to Gelatine.
Besides Gelification, it’s also used as a laxative and an appetite suppressant, depending on the dosage.
If you stick to the dosage recommended below you should be on the safe side though.
Overdosing in a recipe will cause your product to have a rubbery, hard texture.
For gelification, Agar Agar is my favourite additive.
Dosage: approx. 0,3g – 1g/100g

Xanthan Gum (E415):
Used for Emulsification.
Xanthan Gum was discovered in the early 1960s and was approved for use in foods in 1968.
It’s produced by fermentation of sugar. The name is derived from the bacteria used in the fermentation process, called Xanthomonas Campestris.
Xanthan Gum increases the viscosity of a liquid. It can also be used to make foams.
Many gluten-free products contain Xanthan, as it gives products the stickiness which normally comes from Gluten.
High doses of Xanthan work as a laxative (approx. 15g/day). Sticking to the recommended dosage will keep you well below this number.
Dosage: approx. 0,3g – 0,5g/100g

Lecithin (E322):
Used for Emulsification.
Lecithin, as we use it in cooking, is a mixture of phospholipids in oil.
The major source of lecithin is soybean-oil.
Genetically modified crops may be used here but they aren’t detectable in the end-product. Therefore you can never be certain that your product is GM-free.
I use it mainly for creating foams.
Dosage: approx. 0,3g – 0,6g/100g

Calcium Lactate (E327):
Used for Spherification and Reverse Spherification.
Calcium Lactate is produced by the reaction of lactic acid with either Calcium Hydroxide or Calcium Carbonate.
It reacts with Sodium Aginate, forming a skin around a sphere, therefore in Molecular Cuisine both are normally used together.
Dosage: approx. 5g-7g/1l Water (Spherification), 1g/100g (Reverse Spherification).

Sodium Alginate (E400):
Used for Spherification and Reverse Spherification.
Sodium Alginate is refined from Brown Seaweed.
It reacts with Calcium Lactate, forming a skin around a sphere, therefore in Molecular Cuisine both are normally used together.
Dosage: approx. 5g/1l Water (Spherification), 0,5-1g/100g (Reverse Spherification).

Gellan Gum (E418):
Used for Gelification.
Gellan Gum is produced by the bacterium Sphingomonas Elodea.
This bacterium was discovered in the US in 1978.
Other than Agar Agar, gels made with Gellan Gum are heat-resistant up to 70 Degrees Celsius, therefore I use it mainly for creating hot gels.
Dosage: approx. 0,6g – 1g/100g

Carrageenan Kappa (E407):
Used for Gelification.
Carrageenan Kappa is derived from Red Edible Seaweed.
This is one of the oldest additives we know, as it was used in China as far back as 600 B.C.
Carrageenan won’t dissolve in cold water, therefore water must first be heated to at least 60 Degrees Celsius before adding it.
I don’t really use it a lot as I find that I can use Agar Agar in the majority of cases where I want to create a gel.
Dosage: approx. 0,6g – 1,2g/100g

Methyl Cellulose (E461):
Used for Gelification.
I only list this additive because it appears in some recipes I have found. I don’t recommend using it!
Methy Cellulose is produced by heating cellulose with a caustic solution and adding Methyl Chloride.
Methyl Cellulose has one distinctive property that makes it special: it sets when hot and it melts when cold.
This is the one additive I don’t ever use. I have some which I purchased for testing but I don’t prepare food with it.
Methyl Cellulose is also used as wallpaper-glue. Who wants to eat glue?
Another use is in the Adult Movie Industry where it’s used as fake… I leave this to your imagination. With the pictures you have in your head now, do you really want that stuff in your mouth? 😉
Neither do I.
Plus I wouldn’t know why I’d need a hot gel that melts when it cools down.
Dosage: approx. 3g/100g

The Fine Scale: Most important Tool in the Molecular Cuisine

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Molecular Cuisine means that you will be working with things like Agar Agar, Xanthan Gum, Gellan Gum, Sodium Alginate, Calcium Lactate, etc.
These are usually very potent, meaning that you will need only tiny quantities to achieve the desired effect, sometimes as little as 0,3g/100g.
So, if for example you want to turn 50g of soy-sauce into soy-gel, you would need only 0,15g of Agar Agar. Using 0,3g would turn it into Soy-rubber which would be inedible.
Your scale must therefore be able to weigh quantities of down to 100th or a gram.
The maximum tare isn’t really relevant. My scale goes up to max. 200g which is way more than I need. For weighing large quantities of flour, suga, etc. I use a normal kitchen-scale.

To give you an idea on the quantities you need, please refer to the linked page which contains a table with dosages for the different additives:

Molecular’s Little Helpers: Dosage

Molecular Cuisine

I first encountered Molecular Cuisine many years ago… and I hated it.
Actually “Hate” isn’t quite the right word here. “Disappointment” is really what I felt.
It must have been around 2009. There was a restaurant called “Silk” in Frakfurt, located on the premises of the legendary Cocoon Club. This Restaurant actually had a star in the Guide Michelin.
It was run by Mario Lohninger, a really good chef. But here, I think he was out of his depth. Or he tried to follow a fashion-trend. Or… I don’t know.
Whatever it was, it was disappointing.
I have been to many Michelin-star-restaurants but this was the only occasion that I asked myself “wtf? That’s it? That’s the hype? This is just a lot of show without any depth.”
“Silk” closed down in mid 2012, which in my opinion wasn’t a big loss.
It took until 2017 that I started developing an interest in Molecular Cuisine again.
I started buying books on this topic, read articles in the press and finally decided to give it a go.
Meanwhile, I’m a big fan of adding some molecular parts to my dishes. I would never want to create a full molecular 11-course dinner though. That’s what “Silk” did and that’s what disappointed me.
No matter what you think, Molecular Cuisine is pure Chemistry. You need a very fine scale, calculate quantities of those many white powders to the milligram, then nothing can go wrong.
Anybody can buy a book on the topic, buy the devices and the additives on the internet and start doing molecular cuisine. If you stick exactly to the instructions, you’ll be able to re-create the meals of those decorated chefs to the last detail.
I don’t see any creativity there.
Traditional cuisine though, that’s what I regard as an art. You need experience and creativity to prepare a good meal.
And here is where the idea kicked in to combine both.
Preparing a traditional meal with some molecular components takes cooking to a new level.
Sometimes very simple things can take you a long way.
For example, I prepared a dish with fresh tuna the other day. I needed to add quite a bit of Soy Sauce, but I didn’t want the tuna to swim in the sauce.
I took the soy-sauce, added a little bit of Xanthan, stirred and… I had Soy-cream. The taste is exactly the same as of the soy-sauce but it’s really creamy.
Very simple but it really did the dish well.

Tuna Medallions with Pak Choi and mashed Sweet Potatoes. Soy Cream for the Flavour

What I find very interesting about Molecular Cuisine is the fact that they sometimes use devices from totally different fields to improve the quality of their food.
Did you know that if you prepare a sauce in an ultrasonic cleaning-device, the components mix much better than by just stirring it?
This is what I find exciting about combing traditional and molecular cuisine.