Right temperature for White Labs yeast?

[guypettigrew]

In all the time I've been using White Labs yeast I've followed the guidance on the packet regarding the optimum fermentation temperature. For ales this is given as 18°C to 21°C. So my temperature controller has been set to 19.5°C and the fermenting beer has stayed within +/- 0.5°C of this.

Looking on the White Labs site, though, a higher temperature of 20°C to 23°C is given for WLP 001 and WLP 023, which are the two I'm using at the moment.

Does this 2°C matter? It seems quite a big difference.

Thanks.

Guy

[robbym123]

I thought the recommended approach was to start at the bottom of the range e.g. c17.5-18c, then raise to c 20-21 once fermentation starts to slow, to ensure the yeast finishes up properly

[HTH1975]

The breweries I’ve worked at have fermented at 21.5-22C optimal (that’s where the temperature controller has ben set).

You can start off lower and let the temperature rise, but you’ll get a longer lag time. A warmer start temperature will start fermenting quicker, but you’re at risk of harsh by-products of the fermentation process. I tend to pitch between 20-22C and aim to maintain that temperature. Sometimes my homebrew will get up to 24C, but is perfectly fine - it all depends on the yeast.

[Robwalkeragain]

It's entirely strain dependant, general rule of thumb is that fermenting cooler will decrease esters and attenuation, hotter will increase esters and attenuation. So it depends what you're hoping to get out - in reality you can probably use them anywhere between 15/25c with good results. More than anything giving the yeast a constant temperature will help with beer quality, rather than wild swings affecting health

[guypettigrew]

Thanks all.

So, HTH, commercial breweries ferment quite warm. Interesting.

The point about maintaining a steady temperature is good to know. Thanks RWA. The advice in home brewing is often to change the temperature as fermentation progresses.

The controller is now set at 21°C for a White Labs 001. It should stay there +/- 0.5°C with no trouble.

A final query. What temperature do commercial breweries chill the beer down to at the end of fermentation and before casking?

Guy

[HTH1975]

We normally chill down to 10C, and the same was true at the last brewery I worked at. Just enough the get the yeast to stop working and to help it drop out of suspension. Isinglass and finings adjunct help it drop bright.

[Robwalkeragain]

Large commercials will drop it as close to freezing as possible without freezing the beer, Marston's and St Austell go below zero to quickly knock all of the yeast out, then re-yeast in the cask to their desired cell count. Adjunct works better the lower the temperature, ie if you're planning on serving it clear at 6c you need to get it as close as possible to 6c or below before dropping the aux out with isinglass.
Either way, just hold it at low temp for 2 days and you'll notice a pretty significant increase in beer quality. My kit can drop to around 7c which works great.

[HTH1975]

Marston's and St Austell go below zero to quickly knock all of the yeast out, then re-yeast in the cask to their desired cell count.

That seems a crazy approach. We just stop it a couple of points shy of FG, crash, rack to cask, then it carbonates naturally in the cask (with isinglass to help clear it).

[Robwalkeragain]

Marston's and St Austell go below zero to quickly knock all of the yeast out, then re-yeast in the cask to their desired cell count.

That seems a crazy approach. We just stop it a couple of points shy of FG, crash, rack to cask, then it carbonates naturally in the cask (with isinglass to help clear it).

It's fairly normal. Quick results and more control - I do the same as you, but big breweries can have a beer from grain to glass within a week!

[Kev888]

The ranges given by whitelabs (and others) normally give fairly typical results in typical conditions. Different strains behave in their own way, which is why they may be allocated slightly different ranges. But these are only for guidance, they aren't the only 'right' temperatures; these can be adjusted according to preferences and circumstances - e.g. some styles (or some drinkers) demand different levels of ester to others.

The re-yeasting thing is interesting. I sometimes chill to just below zero for clarity; it can be quite effective, but there's still plenty of yeast for natural carbonation. Perhaps their clearing process is more efficient than mine, or possibly the method is more harmful to the existing yeast (e.g. very rapid), unless they just want to cask/condition with a different strain.

Things don't always translate, particularly in the case of bigger breweries. Their objectives, size, equipment or processes might involve things that just don't parallel those of homebrewers (or even micros).