Adding more yeast because I under pitched... Did I? How do I?

RDWHAHB and post this in the Homebrew forum.

 

The logarithmic phase of the yeast life cycle ends when yeast reach maximum cell density, regardless of the osmolarity of the solution. In other words, yeast replicate according to volume, not gravity, so you should be just fine.

 

As a first time brewer there are a lot of little things that you'll experience while brewing that will concern you because the instructions in kits or recipes don't talk about them. I'm going to guess that the reason your OG ended up at 1.075 instead of 1.060 is because of the boil-off of water during the hour that you cooked the wort. At some point before you bottle the beer you'll want to check your actual volume to see if what I said is correct, and then add water to get to the level that the recipe is written for.

I agree with @EvenMoreJesus that your pitch rate is probably okay. (However, was the yeast fresh-dated?) It may take longer for the fermentation to show signs of activity if you underpitched, so sit tight. If you feel that you did a good job oxygenating your wort, don't do any more. Allow the fermentor to sit in a place with an ambient temp around 65 degrees, and if you don't see evidence of fermentation in three days, come on back for further discussion.

Also, take some time to read John Palmer's book HowToBrew.com which is free to read online, or purchase the latest edition so that you have something to highlight, write notes, etc. It's usually $16-$18 online and in good book stores.

P.S. Welcome to the BA site and to the homebrewing forum. We're glad that you're here.

 

There are several calculators out there, but I don't think there are any that would say you need 3 times more cells for a 1.075 wort than for a 1.060 wort. It should be something like 23-24% more.

 

Just to clarify something @Mothergoose03 said and I think you picked up on... Boil-Over doesn't cause gravity to be higher than expected. But excessive Boil-Off does. The former just loses some volume without changing the concentration of the sugars/dextrins in the remaining volume, because you're losing both water and sugars/dextrins. The latter increases the concentration of sugars/dextrins in the remaining volume, because all you are losing is water.

 

It's not only a matter of time, but also how vigorous the boil is. When you have a recipe that predicts a certain post-boil gravity and volume, embedded in that prediction are assumptions about boil length and the amount of water boiled off per unit of time.

Heating (but not boiling) the wort as you collected it probably didn't cause a lot of extra evaporation. But you may well have boiled away more water than the recipe designer had in mind if the boil was more vigorous. And/or if this was an all grain batch, you may have had a more efficient mash than expected, which could also influence gravity upward.

 

That certainly causes a loss of liquid, and depending on how big the puddle was on your floor, maybe it accounts for most of your loss, but keep in mind that some boil-off likely occurred and without replacing it, your final gravity reading will likely be too high also. It's your choice whether you want to guess how much water to put back.

I've never read anything to say how old is 'old' for liquid yeast, but your date doesn't seem very old as long as it's been refrigerated during its time in the store. Is there a "Best by" date? All I'm getting at is the age of the yeast will impact the speed of the work it needs to do, and a slow start may be your first hint.

Are you fermenting in a carboy so that you can see the action when things get going?

 

The good news is that the expiration date is basically meaningless. The bad news is that it's basically meaningless. Yeast cells are dying all the time, i.e. every day, from the time the yeast was propagated.

The truth is that the expiration date and words like "good for X gallons of ale wort up to an OG of X.XXX" are an oversimplification. If you believe, as most brewers do, that there's some ideal target pitch rate (expressed in cells per volume per gravity) for each style (or perhaps each yeast strain), it's easy to see why a standard sized single package, with some number of viable cells that's a function of how old it is, is not going to provide that ideal pitch rate for any given beer (except by sheer coincidence). The instructions from the yeast vendor are really training wheels to help beginners make beer, but are not (usually) going to help anyone make the best possible beer.

My advice, if you decide to stick with this awesome hobby (and you should, because chicks dig it), is to use a yeast calculator (either standalone or as part of more comprehensive brewing software) to calculate when you need a yeast starter (or multiple packs), and how big that starter needs to be to target the pitch rate you want for the recipe.

There are many discussions about ideal pitch rates, and you as the brewer can decide which one is best for your recipe (based on trusted advice or on experience), but once you decide on a target rate, ignore the instructions on the packaging and take control.

 

Nah. That really wasn't the point.

 

Somebody is being modest.

@VikeMan developed this spreadsheet-based version called Brewcipher that is free to download. From reading posts in this forum, it is highly regarded by BA members (although I don't have personal experience to say that because I'm not an all-grain brewer), and you should find out how to download it in this thread:
https://www.beeradvocate.com/community/threads/brewcipher-5.553219/

 

Picture in the works?

EDIT: The answer is probably 'no' since infections don't show up so soon.