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Must I use DME for a starter

I have three AG kits headed my way. I did not think of ordering any DME and only ordered one smack pack as I plan to harvest the yeast for the other two runs. Is there any real reason that I can’t just use corn syrup boiled for an hour in gallon of water?

I don’t have a convenient supply house so this one could be a pain.

If not Corn syrup what other alts would work and how much?

Barry

One option would be to pull a quart or so of your first batch aside and use that as a starter of sorts. Shouldn’t take long to get started and then you can pitch the whole thing into the rest of the batch at high krausen. I don’t think using simple sugar as a starter is ideal, I believe it lacks some of the nutrients you’d want in the starter.

I’d pick one of the kits to short-change on gravity, take about 2 lb of base malt from it, and do a small mash. That should yield 1.5 gal of wort at ~1.035, depending on efficiency.

You could also try to find Malta Goya, assuming you have a decent Mexican grocery selection nearby. That would probably cost more than shipping some DME, though.

Actually I have a few very large Mex stores here. The Malta Goya idea might save me.

What about Malt Powder you can buy at the grocery store for Malt Shakes? That stuff tastes just like Lite DME to me and I would think it is pretty close, being called malt powder.

As far as I know industrial yeast growers don’t use malt based media for yeast growing though I could be wrong.

The reason I had assumed (you how those go) that since you can use corn syrup for bottle priming that it would work for a yeast starter (as flavor would be a minor factor).

I am going to see if I can get NB to add it to my order. They have billed but not shipped. Waiting for them to get to work so they can answer my call. Otherwise I am going to be in punt land. My second option is to call the (somewhat shady) “health food” store and see if they can be bothered to show up to work and sell me something (they are rarely open). Gotta love a health food store where the proprieteress is a chain smoking nutcase. This place gets horibble reviews online.

Barry

No love on the add to order idea. Bill processed = no changes.

SO. It looks like I will be looking for Malta Goya.

I read somewhere about freezing wort from a batch right after running it off, then thawing and boiling to make starters. This is what I do.

It’s my understanding that in an all-simple-sugar growth medium, yeast MAY lose the ability to create maltase and/or maltotriase. I know some people use dextrose all the time for yeast starters with no apparent ill-effects though, so I think some strains may be more flexible than others.

The chemist in me (environmental concentration not biochem)was wondering why corn syrup would not work. Thanks.

Corn syrup doesn’t contain maltose or maltotriose. No maltose/maltiotriose, no need for the yeast to make maltase/maltotriase. Maltose and maltotriose compose more than half of the wort. It’ll be sickly sweet if the yeast can’t eat it.

I just don’t see how growing yeast in sucrose or glucose medium would cause them to lose the genes needed for wort fermentation… Sure they may not be actively transcribed and translated in those conditions, but they wouldn’t disappear and will kick in once they’re in maltose etc rich environment.

Its like feeding a kid a bunch of cookies before dinner. He eats up all those simple sugars and doesnt care to eat the good stuff like broccoli. Sort of.

I don’t think they lose the ability permanently, but glucose definitely inhibits maltose metabolism: http://aem.asm.org/content/62/12/4441.full.pdf.

You can grow a lot of yeast in a glucose-rich environment. You can grow slightly less yeast in a sucrose-rich environment, because sucrose (glucose+fructose) isn’t as metabolically useful for yeast as dextrose (glucose) or maltose (glucose+glucose).

But the point of a starter isn’t just to have a lot of yeast. Having a few very healthy yeast is better than having a lot of very sickly yeast. For yeast grown in a glucose-rich environment, there will be a lag between being pitched into wort and their ability to synthesize maltase.

One reason we make a starter is to reduce the lag time between pitching and the start of fermentation, so “turning off” their ability to ferment most of the wort seems counterproductive, even if they can “turn it on” again.

OK so basically the paper you posted supports my theory. Glucose inhibits MALs and is taken up faster than maltose, probably because there is no point in keeping MAL when glucose is readily available. And once gluc/malt ratio is around 1, MALs start to kick in and skyrocket within 2 hours after glucose depletion. Which means there is a 2 hour lag in MAL activity from glucose to maltose environmental switch. This is also true for maltose grown cultures pulsed with gluc.
The point of the paper is not about this issue anyway.

Now lets consider a glucose starter that was depleted and the resulting yeast placed into an ocean of maltose products… what lag and sick yeast are you talking about exactly? 2 hours to recover while having greater numbers? So if you pitch 100 billion cells that start right away (or not, if you crash the starter) versus 150 billion that will take a couple hours to recover and then get to work… I don’t know… anyone wants to do a split batch?

Another idea could be a glucose starter spiked with malt extract in the end.
:cheers:

There is a lot more in malt extract than sugars that the yeast need for healthy replication. Wort or malt extract has trace minerals, electrolytes, b vitamins and proteins that the yeast use to make proteins (enzymes), cell walls, etc. Commercial yeast growers may use simple sugars for the energy source, but they are probably adding yeast nutrients as well to make sure the yeast are healthy. Making a starter with corn syrup alone would result in less healthy yeast in addition to the maltose issues, unless you add some yeast nutrient to be sure the cells have enough nitrogen for proteins, and other building blocks for cell walls, etc.

Well yeah that’s a given. Didn’t think I had to mention it. Of course you don’t use just sugar.

A split batch would be interesting. I’d go so far as to enter the two beers into a competition and see what judging notes they get.

Yep, they do AFAIK.

When I have run out of DME to make starters, I just wait until my brew day when my boil has been going for 15 minutes. I use a sanitized 1 quart measuring cup and pull off some of the wort and dump it into my flask. Throw it into the fridge to cool and pitch the yeast into it once it has cooled. Toss it on the stir plate and pitch the whole thing when it gets going. Has always worked like a charm. So much so, in fact, that I’ll typically pull a couple of cups of worts at 15 minutes into the boil as a matter of course, cool it, and add it to the yeast I have built up from a starter just to get them going once I have decanted the starter wort.

Never any taste issues from doing it this way and not decanting since the volume is usually pretty small.

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