The popularity of miso has led to an increase not only in the variety of miso available outside of Japan, but the quality as well. Miso will be stocked by any Japanese grocery store and by most Asian grocery stores. Thanks a rise in the popularity of both fermented foods and Asian foods, it's also often found in well stocked grocery stores and health food stores. Look in the refrigerated section, generally near where you'd find tofu. Miso can be made at home if you have access to good soy beans and a good koji (starter culture), but the process is time-intensive and a little bit tricky to get right. If you're interested in it, try exploring the basics of fermentation first.

Though there are countless miso varieties (see below for a primer), the basics for choosing good miso are fairly simple. Look for miso that contains only basic ingredients (i.e. rice, soy beans, salt, koji starter, and perhaps other grains or vegetables depending on the variety). If you can, avoid miso that uses a lot of flavouring additives like sugar and MSG. These tend to be un-aged, quick-fermented, and in some cases pasteurized, all of which leads to a much less complex and flavourful miso.

Miso has a complex and agreeable flavour that contributes a number of characteristics to a dish. At the most basic level, you can expect to use miso to contribute salty and umami (savoury) notes to a dish. Depending on the variety and the amount you use, it may also contribute sweet, fruit, or even earthy notes. Miso has a strong flavour that can easily overwhelm milder ingredients, so it should be used judiciously. Miso is a chunky paste, and is often used as a base or component in sauces, rubs, and marinades. It may also be used to make dips or side dishes, and in some cases is even eaten as a condiment with simple foods like rice.

Preparation Miso is quite simple to use, though the specifics will vary depending on the recipe and the type of cooking. It doesn't need any processing or preparation before being used. Soups and sauces may require that you thoroughly blend or whisk your miso with a little liquid, as it can be quite chunky. Beyond that, any preparation tends to be specific to the recipe. Storage Miso should be stored in an airtight container in the refrigerator. Laying a small piece of plastic wrap directly over the surface of the miso inside the container can also help keep it moist and prevent spoilage. Some varieties are sold with an small flexible plastic liner inside the container that serves the same purpose. Like many 'live' foods (fermented foods with live bacterial cultures), miso can be refrigerated and kept almost indefinitely. As long as your miso looks and smells normal, without any furry growth or obvious spoilage, it should be good to use.

Miso can be categorized by ingredient, thickness, sweetness, preparation, color, and more.  Needless to say, this makes it difficult to accurately categorize the diversity of options.  To make matters somewhat more confusing, some of the names (especially in English) are used interchangeably.  There are simply too many individual miso types to list them all here, but a fairly comprehensive explanation is provided in the tabs below.  Rather than list all the varieties, this section aims to explain the categories. At the broadest level, miso can be grouped in the following ways.  Note that these are categories, and each category may have several different varieties.  In addition, note that there is overlap between these groups, and that any one variety of miso may actually fall into several (or all) of these categories. Regular vs. Quick Miso - though you won't find these titles used (in English or Japanese), these names denote miso made in either the traditional, long-fermented method, or miso made using a quick fermentation.  Quick miso will not develop the same flavour as regular miso, and so it is usually heavily supplemented with flavouring agents.  Regular miso is usually made with whole soybeans, while quick miso may be made with whole beans or a soy derivative.  There is a degree of 'grey area' in this category, as some regular miso varieties are pasteurized or have had a few additives included. One important factor to look for when differentiating the two is texture: regular, traditionally-made miso will generally have small chunks of soybean, koji, and salt.  If your miso is a smooth paste, it may be a quick miso, or it may be a blended regular miso -- you'll have to check the ingredients. Savoury vs. Sweet Miso - This one is relatively straightforward to understand.  Miso can generally be characterized as sweet, which means lower in salt (~7% or less) and higher in carbohydrates, or salty/savoury, which means higher in salt (~10-14%) and lower in carbohydrates.  This categorization tends to separate miso by usage; sweet varieties are more popular for making sauces, spreads, and toppings, while salty/savoury varieties tend to show up in marinades, soups, grilled foods, pickled vegetables, and seafood.  In general, miso is considered salty/savour unless indicated otherwise.  The differentiation is not always indicated in English packaging. Sweet miso should not rely on added sugar for flavour -- instead, it derives its sweetness from a shorter fermentation time, which allows more of the natural carbohydrates to unused by the koji bacteria.  Sweet miso also has a shorter shelf-life, because it tends to continue fermenting to become salty/savoury miso.  Don't let the name fool you -- sweet miso is sweeter, but it is still salty, and certainly not a dessert. Colored (Red, White, Yellow, Black) Miso - This categorization system is commonly encountered in the West, but it's also full of overlap and easy to misunderstand.  In the broadest possible sense, all miso can be categorized as red (actually anything from a deep amber to a chestnut color to a deep, blackish burgundy) or white (actually anything from a pale yellow to a darker beige).  In the narrowest sense however, red miso (aka-miso) refers only to salty, aged rice-based miso.  Likewise, in the strictest sense, white miso (shiro-miso) refers to Kyoto style sweet miso.  If a recipe calls specifically for red or white miso, it is probably referring to those varieties in the stricter sense. The problem with the red/white system is that there are many completely different types of miso within each color group, and (as usual) there are areas of confusion and overlap.  Because of this, other colours are sometimes added to the confusion.  So-called "yellow miso," is a label that tends to be applied to an excellent yellow variety called shinshu-miso, but, given the fact that many misos are actually somewhat yellow, the name can be applied fairly randomly.  Some very flavourful red misos are so dark that they have had the name 'black miso' applied, though this is somewhat uncommon. Chunky vs. Smooth Miso - Another fairly easy category to understand, miso can be understood to be chunky, with pieces of the ingredients visible, or smooth.  This categorization can apply to virtually any miso and has much more to do with use than anything. Chunky miso, as mentioned above, has to be made by traditional means.  The visible pieces are bits of soybean, rice (or other grain), salt, and/or koji.  Chunky miso tends to have excellent flavour, but it can be trickier to use when a smooth end product (e.g. soup or sauce) is desired.  The simplest solution is to press chunky miso through a small sieve or strainer.  Chunky miso is sometimes sold under the name tsubu miso. Smooth miso can be a cheaper quick-miso variety (see above) or a traditionally made variety that has been blended.  In either case, its primary selling point is that it dissolves easily and is simple to work with. Regional Miso - Miso has long had a strong regional flavour thanks to the many farmhouse operations that once produced it.  Though these small operations are becoming less and less common, there are still many regional varieties that one is only likely to encounter when traveling around Japan.  These miso varieties may vary in their ingredients, preparation methods, or fermentation times.  There is also a regional miso native to Hawaii, mentioned below in the section on rice miso. Ingredient Variations - All miso varieties are made with soybeans, however the other ingredients added can vary greatly, and consequently, so can the flavours. Ingredient variations are detailed in the varieties section below.

It's difficult to discuss substitutions for miso given the sheer variety that already exists within miso. When it comes to savoury recipes, you can often substitute one miso for another. Sweet dishes can be experimented with in a similar fashion, but be sure to use an appropriately sweet and mild miso. In either case, the key to success is using miso pastes with similar salty/sweet/savoury profiles. Some miso pastes are far sweeter or saltier than others. For a basic primer, consult the section below. In terms of a complete substitution (i.e. eliminating miso in favour of an unrelated ingredient), no single ingredient will work perfectly, but Korean or Chinese savoury bean pastes could be used in place of some of the yellow and red miso types. The flavour will not be particularly similar, but the overall tone of the dish will be.