So, let's talk about ideal pitch rates in beer.
Now, I'm going to rattle off some information here, and don't get hung up on all the numbers,
we'll explain a little bit more.
Your ideal pitch rate is 0.75-1.5 million yeast cells per millilitre of wort per degree
Plato.
Alright, stop writing.
You don't need to write all of those numbers down.
All I want you to take out of this is that as you increase your volume of beer you're
making, or your gravity changes, that's going to change the amount of yeast that is ideal
to get the flavor profiles that you're looking for.
If you get more or less it will change those flavor profiles that the yeast produce and
potentially add other challenges later in your brew day.
Let's think of ideal pitch rate this way.
Imagine you go to a buffet with one and ten of your best friends, and they lock the doors
and say, "You guys can't leave until you eat of this food."
Now, imagine if you go to the same buffet with you and 200 friends, they lock the door
and say, "You can't leave until you eat all of this food."
The second is going to be a little bit more of an enjoyable experience.
Everything we do as brewers is to make our yeast happy.
There's a fun saying: Brewers make wort, and yeast make beer.
And having the ideal pitch rate gives the yeast the best chance to make the best beer
that you want.
So, when I'm looking at most beers I make I just go right in the middle of that ideal
pitch rate.
That's one million yeast cells per millilitre of wort per degree Plato.
So, one million yeast cells times the number of millilitres.
Now, if you don't know how many millilitres are in a five-gallon batch, it's 18,927, and
that's just common knowledge.
If you didn't know that coming into this I don't think you should take the rest of the
course.
Jokes!
It's around 19 liters -- 19,000.
So, one million yeast cells times 19,000 time degrees Plato.
Now, for a lot of people that may be a new term, degrees Plato, but it's just a different
way of thinking of your gravity.
It's a different scale to measure your gravity.
It's similar to that of Brix.
So, if you have a refractometer, you'll have two scales, one with your specific gravity
and one with Brix.
Most professional brewers, most commercial breweries use Plato when they're measuring
the gravity of their beer instead of specific gravity.
There's a really easy conversion, and while this isn't perfectly linear, it will get you
right in the area that you need to be.
You take the numbers to the right of the decimal of your specific gravity and divide that by
four, that will be your degrees Plato.
For example, if we're at a 1.060, you look at the number to the right of the decimal,
which is 60.
60 divided by 4 is 15.
So, it's 15 degrees Plato.
If you're at a 1.040, again, 40 divided by 4 is 10.
10 degrees Plato.
So, let's recap that.
One million yeast cells time your millilitres of wort -- 19,000 -- times your degrees Plato.
1.060 would be 15.
So, one million times 19,000 times 15.
And that's going to give you your ideal pitch rate.
Now, I'm not going to do that in my head.
Hold on, I have a calculator.
So, I go 1 times 19,000 times -- in this case with a gravity of 1.060 -- 15 degrees Plato.
That is 285 billion yeast cells.
And that's just a quick calculation.
If you guys got 285 then you followed my math and there still hope for me as a math teacher.
I'm not a math teacher!
This is a lot of numbers that I'm throwing right now.
So, pause and breathe for a second.
[Inhale] [Exhale]
Okay.
The biggest thing I want you to take out of this is that often you're not adding enough
yeast and you need to add more.
And that how much yeast you need to add depends on your gravity and the volume of beer you're
making.
If you take that out don't get hung up in the formula, don't get hung up on the calculation.
There are plenty of calculators online that can tell you that exact number so you don't
have to pull out your phone and figure out that it's 285 billion cells.
More importantly is that if you have a beer, say an IPA that's got a gravity of 1.064,
and you're looking at adding one pack of yeast, that is likely is not enough yeast for that
beer.
With most manufacturer being between 100 to 200 billion yeast cells per pack, you need
to look at adding more yeast cells to that to come out with the beer at the quality your
looking for.
Again, this is how we make better beer.
A lot of information.
So let's pause and [inhales, exhales] great.
In the next section we're going to talk about what happens if you over- or under-pitch your
beer.
So, we'll talk about a little bit too much or too little, and what that might do.