There is a lot of debate among homebrewers about whether or not a secondary fermentation is necessary. Some brewers swear by it, while others argue that it is just an unnecessary step that can introduce more risk of contamination or oxidation. As an experienced brewer, I can tell you that the answer to this question really depends on a few factors.
First and foremost, the quality of your ingredients and techniques will play a big role in determining whether or not you need a secondary fermentation. If you are using high-quality ingredients and following good brewing practices, chances are that your beer will turn out just fine with a single fermentation in the primary.
Secondly, the yeast strain you are using and the health of your yeast starter can also impact whether or not a secondary fermentation is necessary. If you are using a pure yeast strain and have made a healthy yeast starter, your beer should ferment cleanly and completely in the primary fermenter. In this case, there may be no need for a secondary fermentation.
Furthermore, the length of time you plan to leave your beer in the fermenter can also be a factor. If you are planning on transferring your beer to a secondary fermenter and leaving it there for an extended period of time, then a secondary fermentation may be beneficial. This can help to clarify the beer and allow any sediment to settle out before bottling or kegging.
However, if you are not planning on leaving your beer in the fermenter any longer than necessary, then a secondary fermentation is not needed. Leaving your beer in the primary fermenter and allowing it to ferment to completion will often result in a clear and clean beer without the need for a secondary.
In my personal experience, I have brewed many batches of beer without using a secondary fermentation and have been happy with the results. I found that as long as I used good quality ingredients, made a healthy yeast starter, and fermented the beer for the appropriate amount of time, the beer turned out great without the need for a secondary.
To summarize, the need for a primary and secondary fermentation really depends on the specific circumstances of your brewing process. If you are using good quality ingredients, a pure yeast strain with a good starter, and are not planning on leaving the beer in your fermenter any longer than needed, then a secondary fermentation is not necessary. Just leave it in the primary and let it go.