Xanthan gum (Kelzan, E415)

Xanthan Gum Hollandaise and Salmon-SMALL
Xanthan Gum Hollandaise

Xanthan Gum (Kelzan, E415)

Xanthan gum is a natural thickening and stabilising agent used to create full flavoured and perfectly smooth fluid gels, purées, and emulsions. It improves or modifies textural qualities, pouring characteristics and cling. The added viscosity that it imparts adds a sensation of enhanced body and mouth feel without reducing flavour impact.

Xanthan gum can also be used as a substitute for traditional thickening agents like gelatine, gluten and starch, where it has been shown to provide better flavour release and a more pleasing texture or mouth feel.

Xanthan gum does not solidify like gelatine, but can become highly viscose or thick when allowed to set. When vigorously agitated the formula will become liquid again. This is known as pseudo-plasticity and is a key feature of Xanthan gum.

Xanthan Gum in Production

Xanthan gum is derived from a fermentation process by a micro-organism known as Xanthomonas Campestri. The fermentation process transforms sugars, nitrogen, magnesium and other minerals into polysaccharides. Polysaccharides, like Xanthan gum, are characterised by large molecules and in some cases are water soluable, Xanthan gum is highly water soluable, which results in thick solutions from very small quantities. Xanthomonas Campestri occurs naturally on plants from the cabbage family and it is often responsible for the presence of dark spots on broccoli, cauliflower and other leafy vegetables.

In production, Xanthomonas Campestri are inoculated in a sterile growth medium until the fermentation process is complete. Post fermentation, the micro-organisms are eliminated through a heat sterilisation process. The Xanthan gum is collected through precipitation, centrifuging and drying, it is then ground into a powder. Xanthan is mostly used in the food industry. However, it is also used in cosmetics, personal hygiene products, and the pharmaceutical industry, where it is mostly used as a stabilizer.

Specification, Limitations and Culinary Uses

Heat

Xanthan gum solutions are unique in their ability to tolerate a wide range of temperatures and will retain their viscosity until a definite “melting temperature” is reached. Melting temperatures are dependent on the strength of the Xanthan gum solution created. However, a strong Xanthan gum solution can maintain its viscosity up to 100°C and above. When the solution has cooled to below the melting temperature it will regain its viscosity once more. Determining the melting temperature of a specific Xanthan gum solution is a matter of experimentation.

This feature allows the chefs to create Xanthan solutions with predictable viscosities at various temperatures. As a result, Xanthan is great for creating perfectly smooth fluid gels and purée, thick and unctuous sauces and unique gelatinous textures.

Tip: Try adding Xanthan gum to a Pumpkin or Celeriac purée for an ultra-smooth result.

Acidity pH

Xanthan gum is virtually un affected by pH and uniform and high viscosity is maintained over the pH range 2-12. However, differences in viscosity with pH are more evident at low concentrations of Xanthan gum.

Salts

Salts have varied effects on the viscosity of a Xanthan solution, but essentially the they are minor and dependent on the concentration of the solution. Extremely low concentrations can experience minor decreases in viscosity, while medium-high strength concentrations actually notice minor increases in viscosity. Mostly this will not have a noticeable effect on your Xanthan creations, but if you find that you are not getting the desired result you might consider this as the cause and adjust your formula to compensate.

Alcohol

Xanthan gum tolerates alcohol up to 60% volume.

Stabilising Effects

One of the benefits of having a tolerance to heat and pH means that the addition of Xanthan gum can help to stabilise sauces that have a tendency to split. Consider sauces like Beurre blanc, Hollandaise, Béarnaise, and Sabayon, which are all emulsions. Typically to avoid sauces like these from splitting and create the desired consistency chefs will add more or less eggs or butter or both (depending on the sauce). Traditionally, this would mean finding a compromise between flavour and texture. Eggs and butter will thicken the sauce while reducing the impact of the flavour base, adversely the liquid flavour base will thin the sauce and increase the chances of splitting. The addition of Xanthan gum will allow you to stabilise your sauce and even increase the ratio of flavour base to butter/eggs.

Xanthan gum is also freeze/thaw tolerant, which means you can freeze sauces that would traditionally split after freezing.

In gluten-free baking, Xanthan adds “stickiness” to reinforces gluten-free flour mixtures. However, it worth mentioning that excessive Xanthan gum will create an undesirable “clumpy” texture.

Tip: Clumping can be overcome through the addition of Guar gum obtained from Guar beans.

Pseudo-Plasticity

As mentioned Xanthan gum has a pseudo-plastic character, which means that when it is allowed to rest it will thicken and when it is agitated or shaken-up it will thin. The advantage of this, given the advantages mentioned above, means that it is perfect for creating coating sauces like salad dressings. Tolerance to pH allows for thick and creamy acid-based emulsions (like salad dressing) and Pseudo-Plasticity allows sauces to be applied to salad leaves and other produce in thin layers, which then sets giving the desired coating effect.

Hot sauces like the Beurre blanc mentioned above can also take advantage of pseudo-plasticity with the use of a stick blender to agitate the sauce before application.

Xanthan Gum Preparation, Tips and Tricks

Xanthan gum belongs to the hydrocolloid family, and as such, its molecules must have time to hydrate after having been dissolved in liquid. This hydration period allows water to penetrate inside hydrocolloid molecules, which then facilitate reactions as they are surrounded by water and suspended in the solvent. Hydration can be done equally well in a hot or cold liquid.

As mentioned Xanthan gum is a robust food additive and will withstand salt, high pH and even alcohol up to 60%, but when possible, it is best to complete the hydration phase before these additions.

Xanthan hydrates quickly at all temperatures, so it has a strong tendency to clump. One popular dispersion method is to disperse in oil (either on a 1:1 or 1:2 ratio of xanthan to oil) followed by vigorously whisking and, optionally, straining to remove any remaining clumps. Another method is to thoroughly mix xanthan with a small amount of sugar, preferably in a mortar, prior to dispersion. This delays the hydration enough to allow the gum to disperse before it has a chance to form lumps. As when working with other hydrocolloids, vigorous whisking or mixing with a hand blender works very well to aid dispersion.

The History of Xanthan Gum

Xanthan gum was discovered in the late 1950s after an extensive research effort by Allene Rosalind Jeanes and her team at the US Department of Agriculture.

In 1964, CP Kelco pioneered the production of polysaccharide gums by viscous fermentation and subsequently, commercialized Xanthan gum. Since then, Xanthan has been used in thousands of applications by a multitude of industries. After extensive toxicological testing that verified its safety, Xanthan was approved in the United States for general use in foods in 1969.

References:

 
Molecular Gastronomy by Molecule-R
 
On Food and Cooking By Harold McGee

Kitchen Knives – The Basics

Kitchen Knives - The Basics Small
Kitchen Knives - The Basics

Kitchen knives – The Basics

In every cook’s life there will come a time when they become sick of using their cheap supermarket kitchen knives and feel the need to upgrade. Cheap knives, made with cheap steel always seem to be blunt, often have poor ergonomics and balance and in the end yield poor results when it comes to fine knife work.

However, once you open Pandora’s box and begin to research high quality kitchen knives you are bombarded with endless information and questions. In the end it all boils down to personal comfort. However, usage and objectives can have a big impact on your decision and so throughout this series of articles we will be covering various aspects of what we believe to be the most important weapon in the chef’s armory, the kitchen knife.

Disclaimer: the kitchen knife is not a weapon and should not be used as such. 😉

Introduction

In this first article we will cover the basics of, price, construction materials, handles and blade balance as well as the essentials knife types every cook should have. If you’re just looking for some quick guidance on which knives every cook should have skip to the end and check out our guide on essential knives.

Price

Buying new kitchen knives is a complex and personal decision, but no buyers guide would be complete without a word on price. Based on our experience €100-€150 should get you a good quality French chef knife or Japanese Gyuto in a reasonable quality stainless steel.

However, as you will find it all depends on your needs. Better steels can yield better results in terms of sharpness and edge retention, better steels cost more money. There is also craftsmanship, high-end, hand forged knives tend to have better ergonomics and balance and once again this will cost more money.

Finally, aesthetics, typically the hand forged blades simply look amazing and at a certain point your simple, practical kitchen knife can cease being a simple kitchen tool and become an artwork. So, in the end the sky is the limit in terms of price, but we think €100-€150 is a good starting point if you are looking for something that will last a life time (with care) and maintain a reasonably sharp edge.

Construction – Materials – Balance

Generally speaking your standard kitchen knife consists of two main components, the blade and the grip or handle. Realistically these two components are all there is and all that matter. However, there are a huge variety of different handles and methods for constructing kitchen knife blades, not mention the myriad different shapes, and these will have a large impact on the ergonomics of the knife.

Handle

There are honestly too many different designs to count, but essentially, they come in two different forms. The most common handle type is the typical western style found on most of the famous brands like the those produced in Germany and other parts of western Europe. Then there are Japanese Wa handles, which have a cylindrical shape and tend to be longer in length than the typical western handle. Wa handles come in a D shape or a hexagonal/octagon shape both have a very comfortable feel to them. Some manufacturers have begun to develop other shapes and forms like the 3D handles on the VG10 range produced by Tanaka Knives, which was developed in partnership with the Kobe Design University. The university used 3D modelling to map the human hand and developed a handle that would be both comfortable and suitable for professional use.

Knife handles come in a range of different materials like various woods, plastics and bonded materials. For most people this is not a big concern, but if you are working in a professional kitchen you may have some restrictions or guide lines which you must abide by. Handles like the micarta handles on the Tojiro Senkou range of knives and the black plastic on the Güde knives are FDA and HACCP friendly. In the end handle material will affect two aspects of your purchasing decision. Looks and feel.

Blade

We’re not going to get too deep into blade construction in this article, but we will write a more detailed post in the future on the subject for those interested. Essentially there are a couple of factors you should concern yourself with and they are the blade hardness, and whether the blade is constructed out of Stainless or Carbon Steel.

The blade hardness will determine how durable the knife is and how sharp the blade can become. Blade hardness is measured on a hardness scale known as the Rockwell scale.  The Rockwell scale measures the tensile strength of a material through applied force and the results are given as a numerical value which will typically range from about 58-68 in kitchen knives. 58 is pretty soft and 68 is really hard. Most good quality knives will be in the low 60s, 61-63 is pretty good.

Briefly, to understand what this all means. Harder steels are able to take a sharper edge and require sharpening less often, while softer steels are the opposite. However, it is also important to note that harder steels require more care with use as they will chip and become damaged if they are used to cut material like bone or hard, non-food products.

Stainless or Carbon Steel

Knives are manufactured with a such wide variety of difference steels there are too many to describe in this post. To cover the basics, you essentially need to know that they can all be broken down into two main categories, Stainless steel and Carbon Steel (more precisely High Carbon Steel – all steels have carbon in them).

Stainless steel is actually not stainless, but stain resistant (some care is required). There are so many great stainless steels and really this is a good choice for anyone who is just beginning to learn about kitchen knives and the steels they are produced in. The advantages of stainless steel are obvious, they require less maintenance. In terms of Rockwell, the average hardness of stainless steels tends to be slightly lower than in carbon steels, but you can still get a very hard stainless-steel knife at a reasonable price, consider just about any knife made in VG10  (HRC 60+) or if you are looking for a premium blade consider R2 or SG2 steel (HRC 63+)

Carbon Steel on the other hand is not stain resistant, but it does have an average hardness which is higher than stainless steel. There is an almost cult following with regard to carbon steel knives and those that enjoy using them will tell you that you can get a sharper edge on carbon, that they are easier to sharpen than stainless steel blades and that due to the hardness of the steel you can find thinner blades in carbon steel.

In our experience carbon steel knives are fantastically sharp and great to work with, but no more so than a great stainless steel. Stainless steel knives like the Kurosaki knives R2 range can be really hard (HRC 62+) and just as thin as a great carbon knife (approximately 2mm). As a chef the last thing you want to be doing is constantly caring for your blade. Our advice is to stick with stainless, but it really does boil down to person preference.

Balance

The length of the blade and the weight of the handle will determine how a blade is constructed. Knife manufacturers employ a range of methods to balance a knife. Some terms you might hear when discussing balance include full tang, half tang and distal taper.

In the end it is nice to have a blade that is centered on the point that you grip the knife. If you tend to use a pinch grip or a combo grip, then you will want this point to be over or slightly forward of the heel of the blade. If you use a regular/hammer or a pointed finger grip, then you will want the balance point to be slightly further back. Most chefs will employ a pinch or combo grip and as such most knives will be balanced over the heel of the blade.

Essential Knife Types – What do I need?

The Japanese have a myriad of different types from the Gyuto, Santoku and Petty to more obscure blade shapes like the Maguro bocho (Tuna Knife), Soba-giri bocho (Soba Noodle Knife) and Hamokiri (Conger Eel Knife). There are over 20 Japanese knife shapes and variations that we are aware of and surely many more. If you look at the western shapes you have the classic French Chef’s knife or Cook’s knife, Paring knives, the trusty Boning knife, Filleting knife, and many more and we haven’t even discussed the various Chinese shapes or those unique to other countries. So, do you need all of them? Certainly not.

Typically, a cook will only need a good French Chef’s knife or some variant like a Gyuto or Santoku, a Petty or small utility knife and a Paring knife. However, if you are regularly breaking down whole animals you may wish to look into a good Boning knife or Hankotsu in the case of fish a Japanese Deba and Yanagiba and in the case of vegetables a Nakiri or Usuba is a handy knife to have around, but in the end it comes down to the type of food you cook and the preparation you need to get down.

Gyuto, French Chef Knife or Santoku?

The classic French chef knife and the Japanese Gyuto are very similar, both are long, wide blades with a very similar shape. The Chef knife is typically a long-curved blade with a flat section near to the heel, the Gyuto is a long flat blade with a curved section nearer to the tip.

The curved section on each blade allows for a rocking, slicing action. The flat section facilitates a chopping movement. So, regardless of your preferred style both knife types will essentially meet your needs. However, as you can guess Chef knives are designed with a preference for a rocking, slicing action and Gyuto is designed for of a more chopping style and slicing movement. If you tend to use a rocking action then you will prefer the Chef knife shape, if you tend to use a chopping action you will prefer the Japanese Gyuto.

The Santoku is a nice option if you are used to working with a shorter blade length (usually about 160mm-180mm), but in the end the shorter blade length is less versatile. Otherwise, Santokus have all the same features as the Gyuto, but the shorter blade length means they are not ideal for cutting through larger produce (water melons for example). However, being shorter actually makes the Santoku a nimbler blade to use. The blade height on a Santoku is the same as a Gyuto. So, as long as the produce you are cutting is shorter than the blade, which is 90% of what you would use a Gyuto for, its actually an easier knife to work with. For this reason, we use both in our kitchen and find that the Santoku is a little more fun and comfortable to use. Just as an aside the Santoku is usually a little cheaper than a French chef or Gyuto also.

Paring or Petty or Both?

A Paring knife is a short flat bladed knife usually about 8cm-10cm in length. This is a great knife for cleaning and preparing vegetables. The compact, short blade makes it perfect for fine detail work.

The Petty is a little bigger and mirrors the shape of a Gyuto, usually around 12cm-15cm. We think its handy to have both, but if you have to choose the Petty is capable of accomplishing everything the Paring knife can do in terms of vegetables and can also be used as a boning knife in a pinch, its slightly more versatile. However, the Paring knife is much easier to work with on those intricate jobs like peeling potatoes or lifting onion skins.

Item added to cart.
0 Artikel - 0,00
304
  • No products in the cart.