Yeast Starters

[Georgedgerton]

The advised temperature for White Labs Bock yeast (wlp 833) is up to 23oC to begin fermentation and then drop to 8 - 12oC when fermentation has begun. Now when making a 1.5 litre starter (Part for brew and part to bottled for later) should you follow the above proceedure or is it advisable to ferment the starter out at a somewhat higher temperature than the lower recomendations?

 

[fraser_john]

Depends on how much time you have!! Though, if it were me, I would make the starter well in advance and keep it on the cooler side, you do not want the yeast mutating due to the warmth and then pitching mutations on your wort!

Further, make a nice large starter early, then on brew day, crash the yeast out of suspension by putting it in the fridge, then drain off excess and pitch the slurry. That way, if you do make your starter with a warm temperature, you are ditching all the unwanted flavours from the starter and only using the yeast.

 

[Stuster]

With a lager, it'd be best to do a bigger starter than that (since you're saving some of that amount). A 2L starter or bigger to pitch, and more to keep. There are definitely different approaches to this, but many people grow starters at room temperature since you are growing yeast and they'll grow faster at this temp. As fraser john says, when the starter is fermented out, put it in the fridge for a day or two to drop out, then decant the liquid from on top of the yeast and just pitch the yeast.

 

[hockadays]

I've just made 5 brews with this yeast and it is good but it is best when you pitch cold. I tried pitching warm and reducing the temp and it threw up a few fruity esters that are unwanted. Best to build up you starter to around 1-2L then chill it down in the fridge. On brew day after you chill your wort down take 1L and put in the freezer while the rest chills down to 10degc. Once the 1L is at around 10degc get your starter and decant the wort off the top of it then add your 10deg 1L of fresh brew to it. Let this kick off for 5hrs while the rest of your wort chills down to 10degc. Your starter should be kicking by the time the rest is at 10degc then aerate and pitch. You should have a full krausen within 2 days and activity within 24hrs.

grow your initial starter up at around 20degc and as you decant the liquid off the top you should have no fruity esters in your beer.

hope this helps

 

[pint of lager]

Lager yeasts require more care than ales. They grow at about 1/2 the rate of an ale. This is why you need a greater pitching rate and starter volume for a lager.

Starter volume is 5% for ales and 10% for lagers. So for a 23 litre lager brew, you want at least 2 litres starter volume of very active wort.

Chilling a starter to floculate the yeast will give your yeast thermal shock. They will no longer be happy active yeast ready to get to work on your brew. They will be sluggish and the end result may be stuck ferments, slow ferments or low attenuation.

If you want to get rid of the top wort, brew a much larger starter, say 20% volume, allow the starter to ferment right out, pour off the waste wort and pitch the slurry. Otherwise, ferment your starter wort at the correct temperature and pitch the whole lot.

 

[Gulf Brewery]

Hi Bruce2

I have had good success pitching this yeast warm and dropping the temperature of the wort as soon as the yeast is pitched. Pitching warm gives you lots of initial yeast growth and then dropping the wort to fermenting termperature over the next 12 to 14 hours as yeast shouldn't be subject to more than a 1C change in temperature per hour.

The main thing is to make sure that you do not shock the yeast by pitching a cold yeast into a warm wort and vice versa - the yeast should be as close as possible to the wort temperature when you pitch it.

Cheers
Pedro

 

[Georgedgerton]

Many thanks for all the input.

The large majority of my brews are ales and I usually decant the starter top wort pitching only slurry. I think it has been good advice to increase the starter volume - and that I will do.

thanks once again for the great response