starting yeast starters

[hopsnhawks]

about ~10 batches in and want to start preparing yeast starters (since it seems like the thing to do)

I have a stir plate, 1" stir bar, 2L erlenmeyer flask, iodophor, foil, DME and the ability to boil water - that is all the equipment I need right?

my concerns at looking over the protocol are as follows, any feedback would be appreciated:

if I boil 2 pints water + 1/2 cup DME for ten minutes won't this boil off most of the water? I don't plan on checking gravity through the process (since I wouldn't have enough to fill a hydrometer test jar) so do I just assume the end product is around 1.040

what's the best way to pour the boiled DME and yeast into the flask without having it smear down the side of the neck and be useless

if I plan on starting this the night before I brew, how much earlier do I need to warm up the yeast before smacking and pitching into the starter

is the DME enough for the yeast or do I have to worry about additional yeast nutrients

much obliged

 

[Jphillips13]

Curious about some of this myself.
I'd imagine for boiling you could cover it.

 

[WoodlandBrew]

If you have a gas stove it's pretty easy to boil the water in the flask. Someone else may have a better idea for an electric stove. Perhaps the transfer could be conducted with a funnel or third vessel that has a spout.

You do not need additional nutrient, the DME is fine.

It should take about 12 hours to reach 90% of the cell count assuming a 9°P 2L starter with 100 billion cells at inoculation on a stir plate. Total cell count at that point should be about 200 billion.

If you put the vial or smack pack in a bowl of warm water it should warm up to room temperature in about half an hour.

 

[flars]

A starter isn't of much use unless you know what size starter to make. Starter size is based on the planned OG of the brew and the viability of your yeast. The viability of the yeast is based on the production date. Her are some calculators to help get you to the right point.

http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
http://www.homebrewdad.com/yeast_calculator.php
http://www.mrmalty.com/yeast-tools.php

In my opinion, because of the shape of a flask, it is less of a boil over risk to heat the water and DME in a kettle, then pour to a sanitized flask.

 

[cjgenever]

If you have a gas stove it's pretty easy to boil the water in the flask. Someone else may have a better idea for an electric stove. Perhaps the transfer could be conducted with a funnel or third vessel that has a spout.

You do not need additional nutrient, the DME is fine.

It should take about 12 hours to reach 90% of the cell count assuming a 9°P 2L starter with 100 billion cells at inoculation on a stir plate. Total cell count at that point should be about 200 billion.

If you put the vial or smack pack in a bowl of warm water it should warm up to room temperature in about half an hour.

Fridge temp to pitch temp in 30 min? That will stress your yeast.

 

[cjgenever]

Go to the brewing network.com

Go to shows

Go to brew strong

Search the archives for the yeast starters episode

Download and listen

 

[WoodlandBrew]

Fridge temp to pitch temp in 30 min? That will stress your yeast.

A refrigerator is at about 40°F. Room temperature is about 70°F. That change is about 1°F per minute. Danstar recommends 2°C (3.6°F) per minute. This is also in line with everyone's favorite book on yeast.

 

[hopsnhawks]

Fridge temp to pitch temp in 30 min? That will stress your yeast.

all it needs to do is (slowly) get to room temp beforehand? I assume I activate the smack pack right before pitching it to the starter?

 

[hopsnhawks]

A starter isn't of much use unless you know what size starter to make. Starter size is based on the planned OG of the brew and the viability of your yeast. The viability of the yeast is based on the production date. Her are some calculators to help get you to the right point.

http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
http://www.homebrewdad.com/yeast_calculator.php
http://www.mrmalty.com/yeast-tools.php

In my opinion, because of the shape of a flask, it is less of a boil over risk to heat the water and DME in a kettle, then pour to a sanitized flask.

thanks, that homebrewdad calculator looks handy

1 liter of water to 100grams DME is a good target?

 

[schematix]

In my 2L flasks, I mix 1250g of water, 125g of DME, the stir bar and a few drops of fermcap-S (CRITICALLY IMPORTANT unless you like beer volcanoes). I cap loosely with heavy duty foil and boil gently for 8 minutes. Minimal water is lost. Gravity is approx 1.040.

I carefully remove from the stove and place in a water bath in the sink. After a few minutes i'll replace the water and swirl the flasks (using a hot pad). Depending upon the time of year and the ground water temp i will repeat this process a few times until i'm down to about 65-70, or until close to ground water temp, at which time i put in the fridge to take down to 65-70. I then aerate, pitch, and throw on the quad stir plate.

I've done this on gas and flat top electric over a hundred times with no issues.

 

[schematix]

1 liter of water to 100grams DME is a good target?

Yes 10:1 by weight, which is 1000g of water to 100g DME.

I find the 2L erlenmeyers max out at about 1.5L water to 150g DME, but it makes me incredibly nervous to put that much in one, especially with a stir bar in there too. I did 1.7L once but I was a nervous wreck for half an hour adjusting all 4 burners. 1250:125 is a good compromise to me.

 

[Natdavis777]

I calculate my starters for 1.6L, so I boil 1600ml water with however much DME per the calculator in a pot for 10 min. I fill my flask with starsan/water and when it comes time to transfer into the flask, I slosh the solution around and then pour it out through my funnel to sanitize that as well. Then transfer into the flask with the help of the funnel and cool in my sink with the help of frozen water bottles (they are reusable and helps not to empty the whole ice chest).

 

[schematix]

That'll get you in the ballpark. 1.6L + 160g DME would get you more than 1.6L of wort, but's close enough for what you're trying to do here.

 

[hopsnhawks]

another question:

I plan on making a 1L starter, sitting it on a stir plate for 12-20hours, then pitching the entire thing in a 5+ gallon batch of wort

due to the use of the stir plate, will my starter be oxidized and if so will the 5% volume I am adding to the wort effect my final product?

 

[WoodlandBrew]

Assuming you are starting with 100 billion cells, 12 hours you'll be at about 90% of the cell count, at 20hrs it should be just about done. (based on measurements I've done)

Good question about the effect on beer quality. It would be nice to hear from someone that has done it. I've always decanted the spent wort. My inclination is that you wouldn't notice it.

 

[trentm]

another question:

I plan on making a 1L starter, sitting it on a stir plate for 12-20hours, then pitching the entire thing in a 5+ gallon batch of wort

due to the use of the stir plate, will my starter be oxidized and if so will the 5% volume I am adding to the wort effect my final product?

Your 5% starter is the upper limit of what the book "Yeast" recommends if wanting to pitch the entire contents, so you should be OK. The negative effects of pitching the entire starter has more to do with off flavors from higher than normal fermentation temps and perhaps foreign wort. If using a similar wort and a yeast strain that doesn't produce off flavors at higher temps or you are propagating at lower temps, you should have less worries. Here is my best guess on the oxygen issue: Oxidation should not be a problem unless you have let the starter continue to spin after the propagation is complete. While the yeast is still reproducing it is keeping oxygen levels in the starter very low.

 

[schematix]

As a rule I always decant anything that ferments to completion on a stir plate. The only time i'd pitch the whole thing would be if its 1L or less into a 5G batch, and it's relatively young (e.g. at high kraussen), and its of a style that isn't significantly impacted by dilution (e.g. an IPA).