Brewlab Yeast Slope - Starter size and other questions

[WM7793]

I have some questions which I hope you can answer regarding the Brewlab yeast slants.

From what I understand, there is approx 40 million/mL yeast cells in their cultures. When pitched, approx (500mL to 20L) will give the brewing wort around 1 million cells per mL.

Is this a figure that is estimated when you are using the whole slant for just one brew?

If I was to make small batches of 20 pints and 40 pints, how would I calculate the starter size required for each, if simply taking a sterile loop sample and growing it on using a stir plate?

Your help, as usual is very much appreciated.

Best regards,
WM7793

 

[WM7793]

Lets rephrase the question, and cut out the maths.

If brewing 23L (5 Gallon) and starting with a Brewlab slant.

What size starter would be suitable, when using a stirplate.

Best regards,
WM7793

 

[pittsy]

I think you should start at 10g of dme and 1020 gravity so that would be 50 ml of water and ever time you step up it should be between 5 and 10 times . Then 50g with 250 ml (1020 ish ) then aim for around 1035/40 for other steps so 250g with 2.5 litre would do it ( if an ale then you can split this into 2 ) if lager avoid 250g step and do 500g with 5 litres step instead and use all that .

 

[Good Ed]

Brewlab recommend that you grow the yeast from the slope with 3 tablespoons of DME in 300cm3 of boiled water an allow to grow for 24-48 hours before pitching, ie at high krausen.

What I do is use the 30g DME and 300ml water ratio, but then step that up, so depending on what the OG of your beer is will determine the size of your starter. I'm planning a 1035 brew next, so I will step the initial starter up with 300g and 3L and split 2 ways, one will go in the fridge and one will be used for the brew.

 

[WM7793]

Thanks so much for your replies, this is most useful.

Best regards,
WM7793

 

[Hopshed]

I do a lot of yeast ranching with these slants. My process is take sterile loop full and innoculate into 15 ml of sterile 1.040 wort, grow for 2 days warm then add to 100 ml sterile 1.040 wort, all made with 1g DME per 10 ml. Then to get final starter for 5 or 6 gallon batch add 100 ml of fully fermented culture to 1 to 1.5 litres of 1.040 wort, and grow out on stirplate. Crash cool for 1 or 2 days before brew day. Before pitching, i decant the crappy liquid and then add sludge to fermenter. Works great.

 

[pittsy]

I do a lot of yeast ranching with these slants. My process is take sterile loop full and innoculate into 15 ml of sterile 1.040 wort, grow for 2 days warm then add to 100 ml sterile 1.040 wort, all made with 1g DME per 10 ml. Then to get final starter for 5 or 6 gallon batch add 100 ml of fully fermented culture to 1 to 1.5 litres of 1.040 wort, and grow out on stirplate. Crash cool for 1 or 2 days before brew day. Before pitching, i decant the crappy liquid and then add sludge to fermenter. Works great.

You should drop the gravity when starting up , 1020 is what i've read until you get to around 500 ml ish starter :-)

 

[rpt]

You only need to use 1.020 wort if the yeast is stressed e.g. from a bottle conditioned beer or an old slant. If it's freshly from Brewlabs then 1.040 is best.

 

[Good Ed]

Apart from yeast from a brewery, Brewlab slants are the freshest yeast that is available to brewers, so no problem about the condition of the yeast, and a wort of 1040 is standard for doing that. Also you should try to follow the rule of the commercial breweries of stepping up x10, this is the optimum, so for example with the current slant I'm working with, I started it off with 30g DME/300ml and stepped this up with 300g DME/3L, I'll split x2 save one and use the other for the brew.

 

[AFewTooMany]

So how long do you leave between stepping it up? Until just after peak activity?