temps

[edwatters]

As a newbie I am a little confused on ferment temps. I know that 25 Celsius is a good start temp but I read here that you don't need to hold that temp for the duration of the ferment. And I also saw that you need to posted. Which is it?

[RoboStill]

Coming from beer & wine, it really depends on the yeast.

Top-fermenting yeasts that many folks use at this scale, such as champagne yeasts, all have their favorite temperature. Higher temp generally yields more esters or fusel production, but this is not always bad. Lower temp will typically just take a long time, sometimes exponentially longer, and too low (<15C) may make your yeast dormant.

I try to keep all my washes fermenting at 25C, although for a straight sugar wash I've pushed it up to low 30's for a speedy ferment. Many yeasts won't handle above 30, and 40 is a typical "kill temp".

While it's preferable to keep a constant temp throughout the entire ferment, I've found if I keep 25-30C in the primary with lots of O2 to get the ferment started and "breed" the yeast, I can put it in the secondary and leave it at 16-20C with no worries. Ferment chugs along happily.

[DeskJockey]

Only done 2 washes so far but the first with EC1118 took 10 days at 25c - I use an aquarium heater,

Second wash I used a whole tin of Allinson baker's yeast (68p from ASDA) at 30c. This is almost finished after 5 days. Tasted it today and its pretty dry already.

Third will also be bakers yeast but may push the sugar up a touch to 5.5kg in a 25l wash to see if Allinsons can handle it.

[Frank]

@edwatters
mate the 'ideal' ferment temp (and the ferment temp range 'tolerated') is very much based on the yeast used. Most/all yeasts will become 'inert' when too cool and restart if temp gets back into the ferment range but all die when temp is too hot and cant be revived.

Generally, most typical yeasts used will work ok between 20 deg C and 30 deg C. Bakers yeasts will go higher. A wash temp per se rises slightly upon the yeast activating and then, slowly, decreases over the life of the ferment. Also the warmer the wash temp, the faster the fermentation completes, but not necessarily for the best results.

So....IMHO for best results, find out what the temp tolerance/range is for your yeast and try to keep the temp as constant as possible in the 'middle' of these temp parameters for as long as it takes to fully ferment your wash (ie constant FG is recorded over time).

[Phantom]

If its a wine yeast, ones for whites and champoo tend to like lower, like about the 19/20C or 68/70F sort of mark, whereas ones considered "red" wine yeast are often tolerant of higher temps.

Frank, I believe has already pointed out about beer yeasts etc (for cooller temps a lager yeast is often better) but its worth remembering that there's less info about alcohol tolerance for beer yeasts as they don't tend to max out the alcohol like with wine type yeasts/ingredient levels so much and many beer worts retain unfermentable sugars that contribute to percieved sweetness.

With sugar washes it does seem a lot of people try turbos then other wine yeasts but don't get the nutition levels or the pH buffers correct which tendto be iincluded in the turbo yeast packs. They also generally have some temperature guidance on them too, whereas with wine yeasts you have to look that up (which is why using the Lallemand brands is easiest, they publish more info/data about their products -lalvin/uvaferm/other ranges - than any other maker)..