I'm new to the home-brewing process and I am attempting an experiment in which brewing yeast is added directly into juice for a period no longer than a week so that the yeast converts glucose into ethanol.

All of the tutorials I've seen documenting their process on DIY juice home-brew (Linked from Life Hacker) don't seem to mention any sort of sanitation process, yet most of the actual home-brewing guides like the one from the American Homebrewers Association put a lot of emphasis on cleaning and sanitation:

If you have spoken with a homebrewer about getting into the hobby, you've likely heard about the importance of cleaning and sanitizing. For many, sanitizing is the most important aspect of brewing. Unwanted yeast can contaminate beer if it is present in your carboy, on your thermometer or anywhere in between. Do not underestimate the importance of cleaning and sanitizing.

DIY Juice Alcohol Process

DIY Juice alcohol guides appear to quite consistent with their process:

  • Obtain pure juice, typically over 20g of sugar per serving
  • Fill a container or carboy with juice (leave room as the fermenting process seems to raise the liquid level)
  • Directly add yeast to solution (it would appear the juice doubles as the "wort"?)

  • Seal container with balloon or airlock

  • Wait 5-7 days for juice to ferment
  • Optional: Move juice solution to sealed container after 3 days if carbonation is desired

Do I still need to apply the same care of cleaning and sanitizing to this simplified "brewing" process or is dish soap and a good rinsing enough to maintain reasonable levels of safety?

3 Answers 3


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.

  • Check this question for a no rinse sanitizer recipe in a pinch. homebrew.stackexchange.com/questions/5837/…
    – SimpleTun
    Nov 10, 2017 at 6:29
  • Make sure to heed the safety tip in the answers too!
    – SimpleTun
    Nov 10, 2017 at 6:31
  • I was actually looking into starsan before I posted this question, but I wanted to see if I actually needed something like it before dropping the cash ion it. My knowledge on no-rinse sanitizers are limited, but it seems they safe to ingest. Is that true? I was also looking into iodine, b/c I have sanitized drinking water in the past with that. Nov 10, 2017 at 6:49
  • Starsan is a phosphoric acid product aka Coca-Cola acid. It is food grade and safe to ingest. Don't fear the foam!
    – SimpleTun
    Nov 10, 2017 at 6:52
  • You only need 1oz per 5 gallons of Starsan. I never mix up a 5 gallon bucket full. A little goes a long way I brew a lot and a $25 bottle of it will last me about a year! I personally do not use iodine but many do with good results.
    – SimpleTun
    Nov 10, 2017 at 7:00

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. .

  • Yes you are correct, but as a beginner post I wanted to offer a scenario with a more controlled environment and fermentation outcome. You don't know what you are going to get from wild yeast but you do know if you control certain variables, sanitation, and take good notes you can repeat a brew by using the same commercially available yeast. Say Lalvin d47 versus whatever is floating in the air. If the wild yeast strain is undesirable then you have wasted your time. You can know more what to expect from a commercial strain.
    – SimpleTun
    Nov 10, 2017 at 11:20
  • 1
    Maybe we should add antibiotics to the brew too? Nov 11, 2017 at 9:01
  • One wonders how Lambic beers are made so repeatably with what is in essence a wild yeast/bacteria mix.The idea that commercial yeast is very predictable is often over emphasised - usually by the manufacturers... Nov 13, 2017 at 12:21
  • I'm actually doing a brew with apple juice. You mentioned that it comes with a bad smell, are you suggesting that sanitation wouldn't help with this? Nov 13, 2017 at 20:51
  • One wonders why it is so bad to stress cleaning and sanitation to a new brewer as to not discourage them when they have to dump the first batch? I am aware of the importance of wild yeast and I understand you need to clean the bio-buildup off of your gear but many new brewers may not. I believe in keeping it simple and slowly add information and other variables as needed.
    – SimpleTun
    Nov 14, 2017 at 6:49

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.

  • 1
    Totally agree. I've done about a hundred batches and never sanitized anything. Regular cleaning is enough. I've only had problems when I tried open fermentation (turned sour), and after I waited too long (2 weeks between brewing and pitching yeast).
    – Robert
    Nov 10, 2017 at 15:56
  • 1
    I despair of the "received wisdom" given in modern brewing. The need to kill everything except the yeast is almost a paranoia. Keeping the brew kit clean and free from bio-buildup is the majority of what is needed. Wild yeasts are not such monsters and are in many ways better than commercial yeasts. Nov 11, 2017 at 9:05

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