Sanitizing: Does the same standard apply for "DIY Juice alcohol"

One reason why you can generally brew without sanitizing equipment is that you are deliberately putting a lot of yeast cells into the brew. So they start with a high population advantage and that allows yeast mostly to out-compete any non-yeast contaminants.

Another reason is that yeast is successful because the yeast cells tend to clump together with themselves and non-yeast cells and either settle to the bottom or to the top in a thick layer. This is a natural process that allows yeast to be a better competitor... I can't reference this, it was something I read in a brewing book many years ago.

The third reason is that yeast produces alcohol! For a lot of competing organisms, alcohol is toxic and will inhibit their growth at concentrations where yeast is quite happy to carry on growing. Alcohol is not a waste product of yeast, it's a deliberate environmental toxin excreted to kill off competitors.

That given, if you don't sanitize the equipment you will sometimes lose a batch to some unwanted non-yeast or wrong-yeast that doesn't make alcohol. If you're making hundreds of barrels a week, one or two failing is acceptable. If you're making only 1 and it fails, it's bad. For that reason, home brewers are best off sanitizing their kit. Commercial brewers also now are best off sanitizing their kit, because they no longer make hundreds of separate barrels but now make many fewer huge vats at at time... so losing one is a big percentage of their work wasted. Also commercially, consumers want a consistent product so presence of any odd flavours from contaminating micro-organisms is not acceptable.

Sanitation can be important, more so if one runs a factory that must hit output targets and timetables. But sanitation can be over emphasized. One wonders how the ancients struggled to make wine without StarSan. However it is perfectly possible to ferment and ferment well without "chemical sanitisers". Boiling water is a very effective sanitiser and just being clean goes a long way. But it does depend on the brewing environment.

Strangely enough I would say that one could ferment pasteurised fruit juice with minimal "hard" sanitation. IMHO the main point is to use a fermenting vessel that is free of debris and organic matter on the walls. Wash the insides of a demi-john well and rinse with hot water and allow to drain. Add fruit juice and then add some yeast. I usually re-hydrate yeast before adding to the fruit juice. Fit airlock and watch it go. It might be noted that some fruit juices work better than others, some blends are very much better than pure juice and that some juice needs dilution to be useful. When making orange wine for example, one might be advised to use oranges on the point of putrefaction, mouldy skin is certainly no barrier to their use.

It is also very surprising how well natural ferments using wild yeast work. Pour (some) juice into a bowl and cover with a muslin cloth. Place outside for a while, eg a morning or even a day. Add the inoculated juice to the rest of the juice in a fermenting container. Let it ferment. It is surprising effective and usually produces a good brew. Lambics are based on such a principle. Country wines are still made today by pressing grapes and putting the must in a sealed wooden barrel. The barrel is usually cleaned just be scolding with boiling water. The wild yeast on the grapes ferments to produce very passable wine - which improves on ageing.

It might be noted that various fruit juice ferments can vary in taste over time. Some brews are awful when first smelled (apple juice is a good example) but mature very well over extended time. Others are best drunk quickly. .

There is always the risk of an infection. You need to sanitize any equipment that comes in contact with the juice with starsan or another sanitizer. I would not use dish soap. I would even spray the yeast packet and the scissors used to open the yeast with sanitizer and put a little sanitizer in my airlock. This is a small and simple step to take and will prevent you having to do it over in a week or two when you have vinegar. What you are describing is almost the steps to making a wine kit so I would practice the same level of care. also potassium sorbate is bad for yeast so check the ingredients on the juice you purchase.