Elementary Yeast Starter Question

[Tobywan19]

I’m new to yeast starters so any insight is appreciated.

So plugging in the info to BeerSmith I get following info for my starter:

1.7 l starter size
1 packet of liquid yeast
112 grams (3.95 oz) or DME
1/4 teaspoon of nutrient

Boil for 15 mins, cool to 80*, pitch yeast and park on the stir plate for 2-3 days.

When I do this, due to boil off over 15mins I end up w much less than 1.7l of starter.

Is BeerSmith calculating this loss? Do I have the right size starter (it boiled down to about 1l)?

Am I obsessing over a minute detail?

 

[jdauria]

Couple things...
Don't worry this time, but that seems like a lot to boil off in 15 minutes. Is the one liter after cooling the starter as you will lose some to evaporation and shrinkage. I stopped doing 15 minute boils for starters about 4 years ago, I only boil for 5 minutes. Never had an issue.

What was the OG of the beer you are making? Using http://www.yeastcalculator.com/ DME calculator, a 1.7 liter starter with 112 grams of DME only has a gravity of 1.024. Unless you are making a low ABV beer, that's a low OG for a starter, I usually shoot betwenn 1.035-1.042 for my starters.

And remember "Relax. Don't Worry. And Have a Homebrew."

 

[Kealia]

I was going to mention that boil off rate as well. You'll also need to know the age of your yeast to plug into the calculator linked above. That makes a big difference in your starting yeast count/viability.

The fact that you are doing a starter of any kind is great, so as mentioned, don't worry too much about this one. Just live and learn.

There are two approaches:
1) Let starter run it's course, chill and decant pitching only the yeast (not the rest of the wort)
2) Pitch it at high krausen which will be in the 12-24 hour range

There are proponents to both approaches.

 

[rhys333]

I’m new to yeast starters so any insight is appreciated.

So plugging in the info to BeerSmith I get following info for my starter:

1.7 l starter size
1 packet of liquid yeast
112 grams (3.95 oz) or DME
1/4 teaspoon of nutrient

Boil for 15 mins, cool to 80*, pitch yeast and park on the stir plate for 2-3 days.

When I do this, due to boil off over 15mins I end up w much less than 1.7l of starter.

Is BeerSmith calculating this loss? Do I have the right size starter (it boiled down to about 1l)?

Am I obsessing over a minute detail?

A couple things to mull over...
Easy rule of thumb to obtain 1.040 gravity starters is to use a 10:1 ratio of water to DME. For 1L that's 100g, and for 1.7L that's 170g.

If I want to end up with a given volume, I'll just add a 100-150 ml extra water to account for evaporation. In your case maybe 1.9L water starting.

Now, regarding the starter question, and you'll get a diverse range of opinions on this. Here's mine. Yeast calculators heavily over-estimate the number of cells required. WY states that 1 pack is enough to ferment a standard gravity 5 gallon batch, and I agree. As long as the pack fully inflates within a day, I pitch directly without a starter. It works flawlessly, and I skip unnecessary steps. As for the number of cells in a given pack (or harvested slurry), I simply estimate about 15% loss per month.

 

[Tobywan19]

Thanks for all the input, and I'll take all this into consideration for next time. This is an IPA with a 1.069OG. I thought a 900mL boil off was pretty high myself, but with no experience I shrugged it off.

So for future brews, I'll use the calc and add 500mL or so for boil off.