Homebrewing is a nice and laid back hobby. It can be fun to brew up a nice batch of beer over the weekend. But, something has always bothered me. How do the local breweries get their beer so perfect, every time? Turns out pitching the perfect amount of yeast cells has something to do with it.
Yeast labs engineer their yeast packages according to average initial gravity. So pitch rates are not something average homebrewers need to worry about. However, pitch rates play a role in the overall flavor of beer. Dry yeast typically contains more cells per package than liquid yeast.
So there you have it, as an average homebrewer you don’t need to worry about pitch rates. But, why would you want to be average? Read below to find out how pitch rates can make you a better brewer.
Higher Pitch Rates and its Affect on Beer Flavor
When it comes to brewing up a nice batch of beer, little attention is made to the number of cells that are being tossed into the fermenter. But, for many years yeast labs have been telling us we should make starters. I wondered why this was.
It just so happens these yeast labs aren’t giving us enough viable yeast cells. For high gravity beers that is. But, are there any side effects to accidently pitching to much yeast?
Turns out if you are over pitching the number of yeast cells you could get a number of nasty side affects. Most of witch are negative.
Wyeast has a list of these issues that you may encounter:
- Very low ester production
- Very fast fermentations
- Thin or lacking body/mouthfeel
- Autolysis (Yeasty flavors due to lysing of cells)
Low Ester Production
This is probably the only issue I see when it comes to overpitching yeast. In fact with the Hefeweizen example above its preferred to have higher esters. So under pitching Hefeweizen yeast is preferred in this case.
But if you are looking for a relatively clean beer, then its important to pitch the appropriate amount of yeast. For lagers a higher pitch rate is likely preferred.
Another reason to reduce esters from overpitching may be if you want to highlight other adjunct flavors. Maybe you decide to add coffee, or a subtle peach flavor. In the end its really about balance and knowing that your pitch rates can help you sway the balance is very useful.
Fast Fermentation
Its no secret that tossing more yeast in will result in a faster fermentation. This is preferred since you want to get that beer done and get to drinking, but what it also does is keep infection risks low.
Thin Mouthfeel
To be honest none of these really seem to be much of an issue to me aside from the low ester production. In fact I recently pitched a package of Mangrove Jacks Hefeweizen ale yeast and didn’t experience any thin mouthfeel.
This may have been because of the specific strain used, or even the fact that it was 50% wheat. In fact mashing temperature can also play a role in this. So even if you are overpitching your yeast you can find ways around some of these ill effects.
Its likely that I didn’t overpitch enough for this to become a problem. Like for example adding like 5 packs of yeast and blowing the crap out of that fermentation.
Autolysis
This can be a problem if you have more yeast, then you have a greater potential for dead yeast. But, for the average homebrewer this is really not a problem. Commercial brewers are likely to have this problem since they are brewing much larger batches.
The more weight that sits on top of yeast sitting on the bottom of a tank, the more of an issue this becomes. So if you are brewing a 5 gallon batch don’t worry about it.
Autolysis is also really only a problem when aging your fermented alcohol for long periods of time.
Temperature of Fermentation and Affect on Pitch Rates
The warmer your temperatures are the more stressed out the yeast becomes and the more esters that you will get from your yeast. This has me thinking a lot about the possibilities with higher pitch rates.
If you are looking for ester production but less diacetyl or fusel alcohol flavors then pitching more yeast is preferred. This has me thinking back to what is suggested when brewing a Belgian beer.
In this situation overpitching your yeast and fermenting the beer a bit higher in temperature than you normally would, will result in more esters and less diacetyls.
This is not always the case though, so you need to check what your yeast package says. Some yeast at warmer temps will produce more diacetyls while others wont.
Most Homebrewers Under Pitch Their Yeast
As a homebrewer I’m here to tell you that you have been screwing up. Really bad, all this time you have been under pitching your yeast. I know, seems crazy right, but its true.
Chances are you are shooting for those high ABV beers and in doing so your initial gravity is much higher and according to every yeast producers you need more than one package of yeast, or a yeast starter.
Yeast Pitch Rate Calculator
I don’t expect you to know off the top of your head how much yeast you should be pitching, that’s why we have these nifty yeast pitch rate calculators.
This one, from Brewers Friend is a great one to get you started pitching your yeast correctly.
If you are consistently needing more than one package of yeast, it may be time to invest in a yeast starter system.
The system I linked to above has everything you need to beef up your yeast before pitching it. The cost of the system may seem a bit high but if you are under pitching by one package every time, you will likely make back your investment in 12 brews.
Yeast Past its Best Before Date
Sometimes you have big ambitions and buy a ton of yeast. The issue is it can be difficult to get through all of that yeast before it passes its expiration date.
Don’t fret though since even if the yeast passes its expiration date doesn’t mean that you can’t use it. Now the number of cells it has is likely much lower than if it were fresh, but you can remedy the situation in a few ways.
- Pitching extra packets of yeast.
- Making a yeast starter.
If your lazy you can just pitch extra packets of yeast, but that does not guarantee you will get a good fermentation going. Instead it might be a better idea to make a yeast starter. That way you know the yeast is viable.
Frugal tip: Tell homebrew supply stores that you will take the expired yeast off their hands for a fraction of the price. Then make a yeast starter before pitching into your wort.
What We Learned About Pitch Rates
Pitch rates are calculated according to the initial gravity of your beer. Most yeast labs will give you the average number of cells for an average type of beer. But anything with a higher initial gravity will require higher cell counts.
On yeast manufacturer websites you can find pitch rates or you can use a calculator like the one at Brewers Friend. Since you are likely under pitching yeast for your beers it may be time to invest in a yeast starter. It is far better to overpitch your yeast than under pitch it. But in all cases the right amount of yeast cells is the best choice.
