I am new to yeast starter. I am making a 2 L starter with Wyeast California Lager which I started last night about 24 hours ago. I will be brewing tomorrow and pitching yeast in the early afternoon (16 hrs from now) My starter has been on a stir plate since last night. It seems to be less active now. I used 1.5L water and 6.76 OZs DME at a OG of 1.036. Should I leave on stir plate till pitch time or take off and refrigerate?
I’d put it in the fridge as soon as you can.
Its in the fridge
Many people here, me included, have stopped using stir plates and gone to the SNS (Shaken Not Stirred) starter. Give it a try next time and see what you think…here’s my writeup and you can find a lot more here on the forum.
Avoid dumping the full starter into your beer. If it has been stirring on a plate, the starter wort can end up tasting awful, and 2L of that can taint your beer. Decant and dump as much of the starter wort as possible, leaving behind only enough to mix up the yeast cake at the bottom of the flask. Or decant fully as use the actual beer wort for mixing.
In addition to the link that Denny posted, here is my blog entry that discusses what I refer to as the “stir plate myth:” Shaken, not Stirred: The Stir Plate Myth Buster | Experimental Brewing
Thanks for posting this I was just about ready to get a stir plate.
Using a stir plate to make starters is a prime example of anti-KISS (Keep It Simple, Stupid). As Denny mentioned, it is just too much effort for what should be a simple process.
By the way, if you do not have a scale that will measure in grams, you should purchase one. Starters should be made using the metric system. A good starter medium contains between 75 and 100 grams of light DME in 1L of water. The mixture only needs to be boiled for 15 minutes at most and then allowed to cool.
So 2.6 to 3.5 ounces of light DME in .26 gallons of water lol.
I’ve got a scale that does grams (use it for my brewing salts additions to my water) and I’m also very comfortable with the metric system and conversions. Really though this was very informative thanks!
To tell you the truth, in practice I haven’t found it that critical. I use 1 qt. of water and 3 oz. DME and it works fine.
Where I find it the most helpful is when I make mini starters for bottle dregs. 10g of DME in 100 mL of water, plus about 100mL of beer & dregs gives a 1.020ish step 1 starter. The math for step 2 becomes pretty simple based on how many mini starters I am combining.
I agree in that situation. For a normal SNS starter, volume has worked fine for me.
The problem with U.S. customary units is that a fluid ounce weighs 1.04 dry ounces (the reason why a gallon of water, 128 fluid ounces, weighs 8.33 pounds instead of 8 pounds). That is a clear cut example of how one cannot fix stupid, but these units have been with us pretty much since we were British colonies. The beauty of the metric system is that one milliliter of water weighs one gram. This relationship makes mixing weight by volume (w/v) solutions dead simple when the solvent is water. A 5% w/v solution has a specific gravity of 1.020 whereas 10% w/v solution has specific gravity of approximately 1.040 (it is very close). Degrees Plato is a said to be a weight by weight measurement system, but is actually weight by volume when using the metric system and the solvent is water. This relationship makes the number before the percent sign the gravity of the solution in degrees Plato (i.e., a 5% w/v solution is 5P and a 5P wort has a specific gravity of 1.020). Eric gave us an example of using w/v to make starter wort. Ten grams of DME in a 100ml solution is a 10% w/v solution. A 10% w/v solution has an S.G. of 1.040. The simple way to make a starter is to mix a 100 grams of DME into a little over 1L of water to allow for evaporation during the short pasteurizing boil. The goal is to have 100 grams of DME dissolved in a 1L solution after the starter wort is cooled, which is 10% w/v or an S.G. of 1.040.
The area where most Americans get hung up with the metric system is that they think in U.S. customary units and then translate to the metric system and vice versa. It is common to work this way at first. However, like learning a foreign language where one eventually starts to think in the foreign language instead of going through the translation step, one eventually reaches a point where one thinks in metric and measures in metric, no translation needed. That is the point where one realizes the disjointedness of the U.S. customary units of measure. A lot people will claim that we use imperial units, but that is not exactly correct. We use a modified version of imperial units of measure that leaves us on an island alone. A prime example is that an English (imperial) pint is 20 imperial fluid ounces, not 20 U.S. fluid ounces. An imperial pint is actually only 19.2 U.S. fluid ounces, some food for thought…
Oh, I agree I was yanking your chain. I learned long ago that metric was superior during my Geoscience undergrad.
Thanks for the in depth explanation though as I am definitely not anywhere as versed as you are in beer.