First Noob question about amount of Yeast needed

CowboyShootist · 12-28-2008, 07:06 PM

Greetings,

I have been reading about home brewing until my eyes are practically bleeding. I have read through the forum, read the FAQs and tips posts here, have the Dummies Guide to Home Brewing and read the online Home Brewing books and blogs. I haven't found a good answer, or really any answer, to this question.

How much yeast is needed for fermentation?

I know that's a wide-open question but let me put it in perspective if I can. I recieved a starter home brew kit for Christmas with an ingredients kit for a Wheat beer. The small pamphlet that came with the brewing kit included another recipe and instructions for making your first batch of beer.

The Wheat kit included a 6g package of yeast while the recipe in the phamplet called for "one packet of Ale yeast" and the LHBS sold me a 15g package of Coppers Ale yeast for that purpose.

Hence the question about the proper amount? Can you actually have too much yeast?

Thanks in advance.

Brakeman_Brewing · 12-28-2008, 07:10 PM

Using the 15g packages of brewing yeasts are just fine, there isnt really any guideline for "too much yeast" (That I know of)

**mmb** · 12-28-2008, 07:13 PM

You can have too much yeast. Over pitching can lead to a decreased ester profile as ester production happens mostly during the growth phase. Shorter growth phase, less esters. In American style Ales, not too much of a problem. In a Belgian where the yeast profile IS the beer, a huge problem.

For proper yeast cell counts, you can use the Pitching Rate Calculator at MrMalty.com.

Mr Malty Pitching Rate Calculator

You should be fine pitching the Coopers pack. An American Wheat, which is what I assume you are going for as available dry yeast doesn't really have the ester profile of a hefeweizen, should be fine with the Coopers yeast.

modster · 12-28-2008, 07:40 PM

ok so question regarding the rate calculator assuming cowboy has a mr beer kit like i have how would we find the O.G. so we can calculate the correct abount of yeast?

billtzk · 12-28-2008, 07:59 PM

Quote:

Originally Posted by modster

ok so question regarding the rate calculator assuming cowboy has a mr beer kit like i have how would we find the O.G. so we can calculate the correct abount of yeast?

The kit recipe instructions usually tell you what OG to expect. You can also calculate it based on the amount of fermentables in your recipe. I recommend Ray Daniels "Designing Great Beers" book as a good source of information, but it's not really written with the beginner in mind. A brewing tool like BeerSmith will calculate it for you, as well.

But this is really not something you need to worry about for your first few brews, unless it is really bugging you. What I mean is, don't hold off on getting started over concerns over how much yeast to pitch. A rule of thumb is that one 10 or 11 gram packet of dry yeast, or one White Labs vial, or one Wyeast Activator pack, is good for a five gallon batch. A 15 gram packet will not be excessive. The smaller Mr. Beer batches can use a smaller amount of yeast, but a 10 or 11 gram packet would not hurt it.

**mmb** · 12-28-2008, 08:01 PM

For a Mr. Beer kit you would be fine with the included packet of yeast.
To find the Original Gravity of your wort (unfermented beer) you would use a hydrometer.

How to Brew - By John Palmer - Appendix A - Using Hydrometers

billtzk · 12-28-2008, 08:43 PM

Measuring your actual OG as mmb said is best, but you can estimate it before you brew it. It won't be precise, but it'll be close enough for estimating pitching rate.

You calculate the gravity contribution from your various fermentable sources in points per pound per gallon (PPG), which is a measure of amount of fermentable sugars in a gallon of wort containing a pound of given extract. It varies according to the source of the extract, since different grains and LME and DME produce varying amounts of fermentable sugars.

Different brands of DME and LME have different degrees of fermentability, but in general DME is about 45 PPG and LME is about 36. You'll commonly see claims of 44 to 46 for DME and 35 to 37 for LME. Unless the brands you buy provide a laboratory analysis (unlikely), the best you can do is approximate.

If the fermentables in your recipe consists of 6 pounds of DME, then:

(6 lb x 45 points) / 5 gallons = 54.

Add the SG of water, which is 1.000, to this to get your estimated OG of 1.054.

It gets more complicated when you derive your wort from a grain mash because your efficiency at extracting sugars will be the unique result of all the variables in your mash process.

While this is all very fascinating, don't let it get in the way of getting your first couple of batches going. You are going to end up spending countless hours reading and studying all the finer points of brewing, and you are going to need to have some homebrew handy to wash it all down with.

modster · 12-28-2008, 09:09 PM

ok so after reading a little im confused. i probably should be sense ive only made one brew. im trying to read as much before starting a second.

So you make your wort and add it to the fermenter then find the og using a hydrometer and add the yeast correct. or am i supposed to let the wort sit a little?

mortimer77 · 12-28-2008, 09:15 PM

haven't brewed much but i'm pretty sure you should wait til your wort is under 90 degrees F. I think i've read that its best at somewhere around 78 F. Also, if you're using a kit, most of the time the yeast comes with it. However, i think if you're using the standard 5 gallon recipe, one packet should suffice.

**mmb** · 12-28-2008, 10:54 PM

You should pitch on wort that's been cooled below 80*F. Ideally you'll pitch at your fermentation temperature.