This is a personal choice for brewers which sometimes sparks heated debates. The final discretion is always up to the meadmaker since they are the head of their own process. However - feedback and process discussion is also a part of the community (especially if you begin to compete).
This info is designed to empower your ability to decide - and choose - the aspects of your process you are most comfortable with. If you are unsure of anything in your process - ask. Our knowledgeable community, especially experienced advanced members, can chime in with thoughtful discussion on how, why, etc.
All the chemicals/additives/etc recommended for use by the wiki and in recipes here are all safe. Anything unsafe would be immediately removed from the wiki or have posts labeled appropriate.
The word 'chemical' gets a bad reputation from the connotation picked up by the food industry. People often understand chemical to mean some kind of industrial solvent/agent designed to perform some kind of reaction, sometimes mimicing a natural reaction, sometimes not.
This isn't the case for the chemicals we use. They are chemicals in the chemistry sense and that they are inorganic. They are often found in nature, produced by living begins, consumed by living begins, and sometimes completely gone by the time fermentation completes.
See the opening paragraph. Modern advances has allowed a large number of opportunities for us to showcase honey as a fermentable ingredient in enjoyable ways. The number of styles have also grown since then, as well.
The historical basis people assume go with mead (such as being the quintessential Viking drink) is not entirely accurate. Many regions made mead and many of them varied with many fruits and spices being added. The modern practices we use are built off the same ideas with some tweaks based on availability of things such as pure yeast cultures, and yeast nutrients, etc.
It is fairly easy to assume that meadmakers of the past used all the best possible practices and ingredients to best ferment the expensive honey they had. It follows to say that using the best possible practices now reflects the same intent to respect the honey and the craft.
The chemicals we use are almost certainly a kind of naturally-occurring chemical, repurposed for our uses in brewing. They are all used in safe amounts for safe purposes.
Many things in the brewing world are not organic purely due to the chemistry definition, ergo are inorganic. Organic is a term commonly used to describe food and food products that have not been exposed to certain chemicals, processes, etc. This does not apply in the brewing world too many things. It does still apply to honey (and in rare circumstances, yeast). Here are is a common example of each:
Sulfites are chemicals that are used to kill spoilage microbes and prevent oxidation. They can also be used to treat chlorine and chloramines in water sources. They are commonly
These are very common in the food industry for the above listed abilities. The wine industry uses it as a standard as does many commercial meaderies. The levels found in wine and suggested for use in your mead are low, typically 25-50 PPM. Other common items have much higher levels such as raisins, which are around 3700 PPM.
Many strains of yeast naturally produce sulfites during fermentation. Some are relatively high sulfite producers (such as Lalvin EC-1118, a commonly used yeast in mead) which may produce up to 50 PPM of sulfites.
Sulfites are still recommended even if your mead is otherwise stable (ABV tolerance, delle stable, or filtered) for its oxidation protection.
Sulfites react with oxygen and off-gas out of meads. Levels drop as exposure to oxygen increase. They pose no harm to humans or the environment.
Potassium sorbate is used to prevent refermentation of meads that have completed primary fermentation. It is used before backsweetening a mead that would otherwise be unstable. It is widely used in the food and health industry for its ability to preserve items.
A tangible possible effect is germanium off-flavors from sorbates. This comes from bacteria that can metabolize sorbate. Always use (and maintain appropriate levels of) sulfites in conjuction with sorbate. Your mead may otherwise go unstable.
Sorbates are naturally occurring in wild berries. They are degraded quickly in the environment and pose no environmental risk.