Slow but effective fermentation

Question

Slow but effective fermentation

Sabre

2019年11月8日 15:15

I have successfully made several (at least 15) gallons of homemade wine, and only really had one come out undrinkable (was black cherry experiment, made a decent cooking wine) I started with a simple balloon and welches set up, amazed it worked, and got hooked.

I digress...

So I have been playing with different sugar contents, how much alcohol I could get vs over sweet, and in general just playing. It always seems to work for the most part. Using gallon glass jugs, 4 going this time.

Some of these batches have active bubbled and foamed for 4+ weeks, average temp 74°F and never shot higher than 19% ABV. I have used everything from grocery store bread yeast to Lavlin EC-1118. Stays active, tastes great, on average goes pretty dry and high alcohol. After it goes clear and settles, degas, bottled, and drank a couple months later.

Most everything I read though [about fermentation duration] states like days, or maybe couple of weeks max.

So I figured I would start getting some more experienced advice, and see what I am really dealing with. maybe start thinking smarter not harder.

I have tried with and without yeast nutrient (Fermax), which seems to make it more aggressive but last just as long and no appreciable difference in end product.

So if someone could nudge me in the correct direction on what to expect or do differently, all info welcome, and thank you.

Topic yeast-nutrient wine fermentation homebrew

Category Mac

Philippe · Accepted Answer · 2019年11月8日 15:15

You have to use an hydrometer to measure gravity if you want to know what is going on. Foam and airlock bubbling activity is not a precise indication of an active fermentation. Measure gravity before fermentation, and then every 3 days. Usually, 3 days in a row of stable gravity means fermentation is done (or stuck!).

When fermentation is done, there is still CO2 in the liquid that is released slowly, giving the impression of an active fermentation. Since you degas your wine, you already know that.

The speed of fermentation depends on many factors, like yeast cell count, temperature, pH, yeast nutrients, quantity of sugar, presence of oxygen, yeast alcohol tolerance...

If you ferment close to 19% ABV, you might have reached the yeast alcohol tolerance threshold, and at that point it will slow down and eventually stop working. You can use a yeast that has an higher alcohol tolerance, but 19% is already pretty high, although some can go up to 25%.

If you maintain a stable temperature of 74°F (23°C), it is the ideal temperature for most yeast. Check the yeast package for ideal range, the hotter the faster. But a faster fermentation might produce a different taste in the final product, you must be aware of that.

Most fruits juice already have sufficient natural yeast nutrients and you don't need to add more. Fermenting sugar only or mead, will requires the addition of nutrients. If fermetation starts within a day, it most probably doesn't need additional nutrients.

I rarely measure pH, mostly because I make the same beer/wine over and over, but if you try new fruits/recipe, you maybe should because:

The optimum pH for most micro-organisms is near the neutral point (pH 7.0). Moulds and yeasts are usually acid tolerant and are therefore associated with the spoilage of acidic foods. Yeasts can grow in a pH range of 4 to 4.5 and moulds can grow from pH 2 to 8.5, but favour an acid pH (Mountney and Gould, 1988).

If you buy fruit juice, make sure it doesn't contain sulfites or sorbate, because they will slow down fermentation.

Some more information about stuck fermentation.

There are many questions here on SE about fermentation, give the search a try and you will find a lot of information.

Slow but effective fermentation

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