@franc1969 gave a good run down. I will twist this to be asking what can I use which follows natural foods rules?
Tannin; the definition of tannin is any of a family of naturally occurring compounds that will complex with protein. Tannins have been used as long as hides have been tanned making leather, ie you could collect tree bark or tannic apples or grapes to produce your own tannin.. All of the tannins are natural and they could be organic if they are from a source which is not sprayed. The commercial product contain non-tannin adjuncts in part because purification could remove their functionality and in part because they are frequently found with related compounds like phenolics which are good good antioxidants and finally the actual concentration is low (I use Prairie Fire crabapples at 1% in rhubarb and cyser ~~ the total phenolics in one reference are 57 mg per milliliter). Tannins are antioxidants and provide long flavor notes to wine. Tannins are a family with flavor descriptions as “soft” “bitter” “hard” “astringent”
Yeast Nutrient; this was not used 200 years ago/ was less important before cleanliness standards were established. A natural source of nitrogen would be bird poop or insects in the fruit. Some old cider recipes have the cidermaster putting a steak in the primary for nitrogen. What else, ,, nutrient demand is less at low temperature ( run at 50F) and at low ABV (build a must at 1.045). The yeast will make the sugars go away with high octane ferment, they canabilize their sisters to finish the job releasing H
2S.
Acid Blend; I attempt to do “natural foods rules” which means that I put together mixes like 4 parts juneberry (low TA/ pH5) with one part gooseberry (high TA/ low pH). If you start this you need to run TA on everything and do a Pearson’s square on the proposed mix. Sometimes theory doesn’t work because of buffering.
Pectic Enzyme; this is an extract from a aspergillus fermentation. As with tannin the weight of actual enzyme is very low. Unfortunately I don’t know of any natural food source. Fortunately this fixes a cosmetic problem, ,,,,, ie we didn’t need it in the first place.
Camden Tablet; most of the use of
metabisulphite is fixing sloppy technique. If you had university equipment you could use vacuum when sampling for tasting or bleed/ flush nitrogen in carboys when racking or run the whole process in a glove box with a CO
2 atmosphere. If you had university equipment you could put a probe in the tank and monitor ReDox potential to tell where your sloppy technique is. NOT practical, even UC Davis or Cornell don’t exclude air from where the professors live and work, ,,, but UC Davis does monitor ReDox so they can see the damage of the chemical soup called wine as it occurs. On the positive 200 years ago no one had metabisulphite and red wines worked, (phenolics are good antioxidants),,,, not so good for whites or fruit wines. This is the first synthetic chemical in your list. ,,, OH should add yeast produce free SO
2 so if you hunted the genetics labs you might find a clone which gives 25ppm or more (legal US rules) during active fermentation
Potassium Sorbate; this is the second chemical on your list. (If you eat bread in the US you are consuming it.) This chemical is not organic and never will be. It is GRAS for the US food system with quite a bit used, ex cow silage has it sprayed on it or breads. I basically don’t use it, I let wines age nine plus months so the yeast are dead. (are you patient?) Another choice is pasteurize the wine like apple cider folks do, OR 0.45 micron filtration which commercial wineries do (commercial guys do not use sorbate/ it looks bad on the ingredient statement).
Bentonite; this is clay of volcanic origin. It is recognized as organic and meets natural food rules. If you don’t want it from the store you could drive to Oregon with your shovel and dig some out of the old volcanic flows. There are two types mined, a sodium or a calcium clay.
3000 years ago wine was made in clay amphora without any of the additives. It wouldn’t be crystal clear, ,,, it wouldn’t ever be sweet, ,,, BUT the process was reliable enough that one wouldn’t get food poisoning.AND the shelf life might end up with other safe natural foods like balsamic vinegar ,,,, so how important are the cosmetic traits?
by the way welcome to wine making talk