Chris79 said:
Fair point Nosco and Rocker!
I'll stay the path with DME, going forward.
I'm going to do a BIAB on my stove, about 16-17 finishing volume. I'm using WLP838, it will be a second generation yeast by that time. My next wort should have an OG of about 1052.
Beersmith says, 2 liquid yeast packets, and recommends a starter size of 3 litres. Under the head of Liquid yeast starter, I changed the starter size to 3 litre, and it says to use 287gm of DME. So I guess I need to make a 3 litre starter? It will be properly 2 or 3 weeks max between the current lager, and the Vienna lager.
The yeast original had a date of 16 Oct 2016. It's finishing fermentation right now. I'm not clear on what I should have enter for the viability? I am also not clear on the amount of viable cells I should have entered from the origin liquid yeast?
I'm still getting my head around this area of brewing. Thanks for the help!
Although I use Beersmith, I dont use it for starters. Only because I use Brewers Friend yeast calculator.
First, you need to work out how many yeast cells you need. This depends on your batch size and OG. For example, 25l of approx 1.050 will need about 250 billion cells (dont quote me on the numbers, but its approx there).
You can then use a calculator to work out how much slurry you may need from a previous batch (sounds like you are doing this), I think Brewers Friend does this, and also I believe Mr Malty does. You would then measure (in a sanitary fashion) the amount of slurry you would need for the new batch from the prev batch, and pitch.
You could also build a starter from slurry (e.g. 1.5L 1.040 DME wort with x mls of slurry, dry yeast, or liquid yeast) to build up your required cells. Remember, you want to step up cell multiples of between 5 and 10 times (e.g. 50 bill to 250 bill etc).
2 liquid yeast packs will be 200 billion cells (100 bill each). Many people use a proportion of a pack in a starter to build the requisite cells (e.g. 25ml of liquid yeast in a 1.5l starter equals x million cells). Use a calculator, such as Brewers Friend etc for this.
Yeast viability will degrade with time. Calculators will work this out. e.g. 100 bill cells today will be x percent less next week etc. Roughly about 1 percent per day I think.
So, we can help with a bit more info if the above is not clear. Batch size and OG, and what yeast source do you want to use. If slurry, when did it finish, if a pack, what was the production date etc
Good to see you are in to it, nice work!
Cheers