Hello Ecologyval, thank you for your question regarding organic fertilizers and the homemade recipe that you shared.

I'll answer your question about the homemade recipe first: 

What that recipe is essentially describing is starting a low grade fermentation via the use of yeast and sugar in a "large" bucket of very warm water. The water needs to be warm in order to kick start the fermentation process. That part of it works to start a ferment, it's essentially what you start with if you were making your own wine or mead (though you'd need more digestible carbohydrates for that, but I digress).

What I'm NOT seeing in that recipe is anything that would provide a substantial nutrient boost for your plants. Typically you'd need to add additional ingredients like dung, finely ground compost, rockdust, anything really that would provide more nutrients to your plants when applied to the soil.

Like this fermented fertilizer recipe from Cornell: https://smallfarms.cornell.edu/2019/01/recipe-for-success-brew-your-own-biofertilizer/

Fermenting these ingredients (well, all but the rockdust anyways) breaks them down into forms that are more bioavailable to your plants. The rockdust breaks down on its own slowly, it's a fairly common ingredient in organic fertilizers but I'll stress not to expect huge results from rockdust alone; think of it like one member of the team doing its part to improve the nutrients in your soil.

I cannot vouch for the fertilizer recipe mentioned in Heloise's column for the following reasons:

• The fermentation has, at most, roughly three hours to build a yeast colony before you are supposed to use the mixture to water your garden. This is simply not enough time for the yeast colony to do much, if anything, especially at the sugar quantity provided in the recipe
  
• As I previously mentioned, there's basically no nutrition in the recipe. The cider vinegar might provide a very minute amount of trace elements, but if that small amount helps at all it's likely more from providing a temporary acidifying effect on the soil. That in turn "might" help make certain nutrients more bioavailable, depending on the PH levels of your soil and what kind of organic materials are found within. A single capful in more than a gallon of water is not likely to do much of anything substantial on its own. I tried to find any reputable examples of using cider vinegar in a way similar to the method described, I was not able to find any literature supporting using it this way

If the yeast colony were given more fermentable carbohydrates, and were given days instead of hours, the resulting ferment might be able to provide a substantial nitrogen boost when added to compost that is actively composting. Do NOT apply it to your plants directly; the alcohol content will likely do more harm than good.

So, since that recipe isn't likely to work, what do we recommend?

Cornell's recipe looks like it could work well, provided that you can find the ingredients and that it provides the nutrients that your plants wouldn't be getting enough of otherwise: https://smallfarms.cornell.edu/2019/01/recipe-for-success-brew-your-own-biofertilizer/

Otherwise, any organic fertilizer that provides the nutrients that your soil is lacking should help. To know what those nutrients are, you'll first need to perform a soil test. Your local extension office should be able to assist you with that, their info can be found here: https://montgomery.osu.edu/program-areas/master-gardener-volunteers

More information regarding selecting organic fertilizers can be found at the links below:

https://digitalcommons.usu.edu/cgi/viewcontent.cgi?params=/context/extension_curall/article/1147/&path_info=Selecting_and_Using_Organic_Fertilizers.pdf

https://cmg.extension.colostate.edu/Gardennotes/234.pdf

https://extension.oregonstate.edu/gardening/techniques/guide-understanding-fertilizers



I'm glad that you found the info useful. Good luck with your garden!