conflicting info. on yeast starters ...

[justenoughforme]

i was told on here not to use corn syrup for my yeast starters as it acclimates the yeast to only simple sugars.
... but i also read that you want to use light LME not dark because it's easiest for the yeast colony to grow in the simpler syrup.


is there a definitive answer?
... the starter with corn syrup really took off, tons of bubbles. and gave me a very vigorous brew with LOTS of krausen.

... i'ts harvested yeast from a previous batch of saffbrew abbeye

 

[Vamptrump]

When you create a yeast starter using simple sugars such as corn syrup you are effectively "training" the yeast to eat these types of sugars.

They sugars from LME/DME are going to be different types of sugar than you would get from corn syrup. You want healthy yeast that will be trained to eat these sugars. The reason for light over dark has to do with the complexity of the overall solution, it will contain other compounds that will make it harder to build the healthy yeast population.

Hopefully that helped.

 

[d3track]

Using extract gives the nutrients for the yeast, just sugar doesn't supply the nutrients. I'd use dme vs lme simply for the fact I find it much easier to measure and store.

I don't have my yeast book here to reference, but I would minimally call using wort a best practice.

 

[stpug]

It's the difference between feeding maltose vs fructose.

Feed a kid hot dogs only and the chances that they'll eat a hamburger is slim to none

 

[justenoughforme]

thanks guys that helped a ton

 

[Vamptrump]

It's the difference between feeding maltose vs fructose.

Feed a kid hot dogs only and the chances that they'll eat a hamburger is slim to none

Way to simplify my response. Go go analogies!

 

[outside92129]

As said previous it's the type of sugars and the other nutrients that differs between simple sugars and malt extract. Here are some details:



Table Sugar(sucrose):50% fructose and 50% glucose


From the FDA:
http://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm324856.htm

HFCS (high-fructose corn syrup) from 55% fructose and 45% glucose, up to 80% fructose and 20% glucose
(using HFCS55, HFCS42 is mainly for baking, etc)



From Briess:
http://www.brewingwithbriess.com/Assets/PDFs/Briess_PISB_CBWPilsenLightDME.pdf

TYPICAL ANALYSIS
Solids ...........................................................................97%
Fermentability...............................................................75%
FAN (syrup As-Is)........................................................3700
*Color (8º Plato) ........................................... 2.0º Lovibond
CARBOHYDRATE PROFILE (100g as-is) (Dry Basis)
Glucose......................................................13 .............13%
Maltose.......................................................43 .............48%
Maltotriose..................................................13 .............14%
Higher Saccharides....................................17 .............19%



From Palmer:
http://www.howtobrew.com/section1/chapter3-5.html

Typical Sugar Profile Extracted From Malted Barley
Maltose 50%
Maltotriose 18%
Glucose 10%
Sucrose 8%
Fructose 2%
Other Complex Carbohydrates including Dextrins 12%

 

[Gavin C]

i was told on here not to use corn syrup for my yeast starters as it acclimates the yeast to only simple sugars.
... but i also read that you want to use light LME not dark because it's easiest for the yeast colony to grow in the simpler syrup.


is there a definitive answer?
... the starter with corn syrup really took off, tons of bubbles. and gave me a very vigorous brew with LOTS of krausen.

... i'ts harvested yeast from a previous batch of saffbrew abbeye

That was me.

The others here have given a better description. Hot dogs and burgers is a good one.

A starter is just a little beer. You want it light (under 1.040) so as to give the yeast a good environment and feed them what will be in the beer. Unlike a beer you will drink you want lots and lost of O2 getting in during ferment. Flavor of the starter is not a concern. You only want to increase you number of healthy yeast and possibly confirm the viability of yeast, if there are any concerns.

A rapid, violent fermention is not indicative of a healthy fermentation. The lag phase during fermentation is important too. A violent rapid ferment does not mean an unhealthy one either of course, but one does not equate with the other.

Another reason you would use as light a dme as possible, is that you don't want starter wort affecting the color of a beer. Not an issue if you're making a stout, but certainly one if you are making a pilsner.

 

[agrazela]

I make starters (and yeast to bank) using high maltose tapioca syrup, yeast nitrogen/vitamin base and peptones, and it works a treat. Then I centrifuge down the yeast and decant the spent "pseudo wort."

But if I didn't have access to all that stuff (thanks, lab job!) I'd use DME, fridge to flocc, then carefully decant the spent wort. Which I have also done.

I have not used standard corn syrups / glucose syrups to make a starter, but I'd be willing to bet that growing a single generation of yeast for immediate use--that is, not creating and banking multiple generations--would work in a pinch. I doubt very much that the yeasts would lose their taste for maltose that quickly.