yeast starter boil off

[Arbe0]

I made a 1 L yeast starter and ended up with .75 L. Because I added DME and Water for the 1 L starter, will I still get enough to bring the yeast up enough? Made the starter with 1L water, 3.6 g of DME for a 3 gallon lagger at 1.057 OG, needed 2.37 billion cells. Will I still get the right amount for my beer when boiled down to .75 L?

 

[rburrelli]

Why would you be boiling down a starter? You don’t boil that long.

 

[Arbe0]

how long should I boil? I have seen 15 minutes of boil for the yeast starter isn't that correct?
some missing info/ Festbier using German Lager WLP830, 3 gallon brew.

 

[McMullan]

DME has been boiled already, before being dried. So there's not much point in actually boiling with the lid off. A short 'boil' for about 15 minutes is just to dissolve the DME quickly and ensure it's sufficiently sanitary for a yeast starter. I find it better to control evaporation/water loss (maintain starter gravity @ 1.040) by simmering with the lid on. Just keep an eye on it, lift the lid occasionally and adjust the heat if necessary. You might want to reassess how you plan to culture enough cells for your lager fermentation. 0.36% (w/v) DME is a bit low and might not even elicit much of a biological response from the yeast. They might even conclude you're having a laugh. Use about 10% (w/v) and aerate well. For a lager at your batch size, you might want to consider stepping up from, say, 500ml to 2500ml.

 

[madscientist451]

I haven't been boiling my DME starters. I was under the (maybe false) impression that at 180F or so the water is sterilized and its not necessary to boil the DME/water mixture. So I usually get the water boiling, shut off the heat and add the DME. Am I doing it wrong? I haven't noticed any issues.

 

[McMullan]

I haven't been boiling my DME starters. I was under the (maybe false) impression that at 180F or so the water is sterilized and its not necessary to boil the DME/water mixture. So I usually get the water boiling, shut off the heat and add the DME. Am I doing it wrong? I haven't noticed any issues.

Sterilised at 180F? You'd be lucky to achieve a satisfactory level of sanitation at 180F. It depends what's going in there, of course. And how much faith you have in your water and your DME supplier's processes. I mash out for 15 minutes @ 78℃ and the spent grains go absolutely rank if left for a day at ambient temperature. Nor is a 90-minute boil enough to sterilise wort. It's sanitising effect is only temporary and why it's so advisable to get fermentation going as soon as. A stalled start to fermentation - due to poor pitching practices - is just inviting problems, increasing the chances of failure.

 

[kevin58]

180° will not sterilize. Sanitizing and sterilizing are two different processes.

 

[hotbeer]

Just get some dry yeast that can be direct pitched and be done with it.

 

[madscientist451]

Sterilised at 180F? You'd be lucky to achieve a satisfactory level of sanitation at 180F.
Sorry, your lazy corner-cutting isn't something I'd prescribe, but you're entitled to choose whatever methods your acceptance criteria decides work for you.

I heat the water to boiling , then shut off the heat and add DME, so my starter solution stays above 200F For a while.
I started using that process after making some no boil extract NEIPAs without any issues.
It turns out you can cut all kinds of corners.
A lazy brewer,? Yup, that's me.
I also sometimes re fill kegs without disassembling and cleaning every part, dont wash my yeast and have dumped wort into just empty carboys (to re-use the yeast cake) without any cleaning. Yeah I know, the details of a lazy brewers day can be downright disgusting.

 

[Arbe0]

DME has been boiled already, before being dried. So there's not much point in actually boiling with the lid off. A short 'boil' for about 15 minutes is just to dissolve the DME quickly and ensure it's sufficiently sanitary for a yeast starter. I find it better to control evaporation/water loss (maintain starter gravity @ 1.040) by simmering with the lid on. Just keep an eye on it, lift the lid occasionally and adjust the heat if necessary. You might want to reassess how you plan to culture enough cells for your lager fermentation. 0.36% (w/v) DME is a bit low and might not even elicit much of a biological response from the yeast. They might even conclude you're having a laugh. Use about 10% (w/v) and aerate well. For a lager at your batch size, you might want to consider stepping up from, say, 500ml to 2500ml.

I have used a yeastcalculator.com and Captain brew yeast calculator at times to find the right amount of DME and starter volume. Using the lager at 3 gallons and OG of 1.057 it says I need 239 billion cells, I set the calculator at 1 L starter volume. Using a stir plate using the K troester I find I get 237 billon and the J Zninasheff it shows 223 billion. looks like I missed it by a few. What is the difference in each of the stir plates? Not sure which one to use. the one I have is black bought at the local home brew store (not sure of the name I think it is called "the Stirstarter Yeast stir plate" ) that can do up to 2000 ml.

 

[KeizerBrewr]

I use my electric water kettle to heat up the needed volume of water for the starter I need. While that is coming to a boil, I weigh out the needed DME, pour it into my flask, drop in my stir bar and wait for the kettle to finish it's process. Then it's just the matter of pouring it into the flask and swirling the water and DME around until it all dissolves. Once it dissolves, the top gets a piece of aluminum foil over the top and into the water bath it goes to chill down to 72F. You should look to overshoot your needed pitch rate, that way you can always thief some for future batches.

 

[IslandLizard]

Using the lager at 3 gallons and OG of 1.057 it says I need 239 billion cells, I set the calculator at 1 L starter volume.

That estimate seems about correct.
I mostly use this yeast calculator:
BrewUnited's Yeast Calculator

Using a stir plate using the K troester I find I get 237 billon and the J Zninasheff it shows 223 billion. looks like I missed it by a few.

They're just different grow models, or estimates of such. Not a big difference or anything you'd notice, as everything in yeast business are just approximations anyway.

The health (vitality) of the yeast cells at the time of pitching into your batch plays a major role, too. Coming directly from a stir plate starter their vitality should be about optimal, so even if you're a bit short on cell count (say, as much as 10-20% short), chances are it will still be fine.

But... in a 1 liter starter of 1.040 you'd only get that target pitch amount of 239 billion if your yeast package was manufactured quite recently, and never mishandled like extreme temps during storage or shipping. The yeast we buy is typically 2-4 months old and shipped at some point during whatever weather conditions at that time.

With that in mind, in your yeast calculator, don't forget to set your liquid yeast's age, by using the date of packaging/manufacture, or 6 months before the "best by" date, whatever is on the package.

In my calculator (above), even if your yeast package is 3 months old, and your starter wort was 3/4 liter of 1.050 (instead of 1 liter at 1.040) you'd still have around 192 billion cells once the starter is done. A little low, but I don't think is something to worry about. Don't cold crash, just pitch the whole thing right off the stir plate, for optimum vitality.

And aerate, or better, oxygenate well at time of pitching. That makes a big difference too.

 

[BeerAndTele]

I hope you meant 3.6 oz of DME rather than 3.6 g. 3.6 grams won’t do it; you’ll need 100 g (3.6 oz) with 1L for a 1.040 starter. Depending on exactly how much boil off you had, you’ll be north of 1.040 but you’ll be alright. And as islandlizard said, depending on the viable cells you’re starting with, you could be a tick short … but you’ll be in the right neighborhood and your yeast will be ready to rock. RDWHAHB.

 

[IslandLizard]

I hope you meant 3.6 oz of DME rather than 3.6 g. 3.6 grams won’t do it;

The OP provided the correct information in #10.
Also some critical additions to his OP in #3.

 

[BeerAndTele]

The OP provided the correct information in #10.
Also some critical additions to his OP in #3.

Ah, my bad. I missed that.

 

[McMullan]

I have used a yeastcalculator.com and Captain brew yeast calculator at times to find the right amount of DME and starter volume. Using the lager at 3 gallons and OG of 1.057 it says I need 239 billion cells, I set the calculator at 1 L starter volume. Using a stir plate using the K troester I find I get 237 billon and the J Zninasheff it shows 223 billion. looks like I missed it by a few. What is the difference in each of the stir plates? Not sure which one to use. the one I have is black bought at the local home brew store (not sure of the name I think it is called "the Stirstarter Yeast stir plate" ) that can do up to 2000 ml.

Unless you're actually counting cells I'd take any recommended pitching numbers with a pinch of salt. It's a ridiculous pretence otherwise. It's a bit like predicting the length of a piece of string by guessing what the two ends look like. I'd advise home brewers to work on starter volumes instead and make empirical observations. Everyone can manage that without a microscope. For example, you'd expect your lager to be done fermenting within about 7 days. If it takes longer you're under pitching. Stir plates are a great way to keep yeast cells suspended in wort to better access resources for growth. The rpm only needs to be sufficient to keep the cells in suspension. There is very little difference between home made stir plates made from HD magnets glued to PC fans and $$$ lab models. They spin at controlled speeds. That's all. Faster doesn't equate to significantly higher growth. A starter much bigger than 2000ml can be prepped on a stir plate described as being suitable for up to 2000ml. As long as it's strong enough to hold the weight, of course.

 

[Conehead]

I get a standard 500 ml of evaporation in my starters. I make a larger starter every time. I boil for around 5 minutes. I use 50/50 RO/well water in my starters. No science behind that, just what I do.

 

[Arbe0]

Thanks guys for all your iformaton. l have re-educated myself on starters. seems I had more to learn that I thought I knew after many years of brewing (mr know it all here).