call me stupid but I just can't follow the calculator that is on this site. Is there a yeast calculator that i can use that is understandable? For instance, what do the options for the target pitch rate calculate to the OG of the beer I am brewing? Let's say I am doing a Amber Ale which option goes with the batch I am going to brew? I don't know how the Pro Brewer numbers compare to what I am brewing. I have an attachment that shows how I think I am supposed to configure the calculator, but I don't know if it is correct. I read this as I would need to add 2 1/2 packets of yeast for the batch I want to brew. Please review as I could use some help getting this figured out.
Don't get too hung up on pitch rates, they're like a hand grenade, you only need to get close.
The pitch rate is based on mostly gravity and volume. Typically an ale gravity of 1.045-1.060 can get by with a .75 pitch rate. Most ales fall into this category, the example you show in your post is way too high in it's pitch rate. You could even get by with as low as .35 pitch rate with certain dry yeast. S04 works well with lower pitch rates as long as the gravity isn't too high. Set it at .75 and see where the calculator lands. If it shows .5 with a lower gravity beer, it will likely be fine. Some have argued that .75 is too high, but I would avoid going below .5 unless I knew the yeast could take it. .35 pitch is the lowest I would ever go, even with S04.
The other variable is cell density per gram with dehydrated yeast. The yeast manufacturers often use fairly conservative numbers when it comes to how many live cells are in each gram. 8 billion cells per gram is really conservative, some suggest it's closer to 20 billion cells per gram. I usually estimate it's @12-14 billion cells per gram, regardless of strain.
I put into the calculator the gravity and volume of the beer you had as an example.
As you can see, a 11 gram pack of yeast will yield @ 132 billion cells. That will give you a .56 pitch (.56 million cells per mL per degree plato). This pitch rate should give good results. If you go beyond 1.060, then you will need at least a .75 pitch, you could bump it up to 1.0 pitch to make sure the yeast will produce a good beer. A beer with a starting gravity of 1.080 needs a bigger pitch rate to prevent off flavors and to make sure the beer is attenuated well, then the pitch rate should be 1.0 or more.
When I use dry yeast, I try to use the full pack, so if it's a little too low, I'll add another pack and see what pitch I get. Over pitching yeast is less of a concern than under pitching and open packs of dry yeast don't keep very well.
Some strains will produce a really high krausen and come out the top when over pitched, again S04 is an example of this kind of yeast. US05 and 34/70 will behave better when slightly over pitched.
Hope that helps to clear things up.
