Corn Sugar Starter. I know what you're thinking.

It's not that. My LHBS SAID I COULD WITH NO PROBLEM. So I got some questions.

Why not?

I have read over and over that the yeast will :
a) Become accustom to their environment and when poured into wort, may be shocked and many may die.
b) Be unable to ferment maltose to the extent it would have because it has found an easier time consuming simple sugars. It would also most likely floc out and stop before the job is done.
c) This happens at such a rate because you are creating a new generation, or two, in one environment so they evolve to survive. Then you switch there environment and only the first generation is adapted. So you've just undone the work of the starter.

But.
I have recently had a talk with LHBS guy who has been reading the new yeast book they have and is telling me all about his starters and propagation. At first I didn't say anything because, hey, I don't know everything. Maybe the science has changed. He said the book went to explain that, "sugar is sugar is sugar". I went on my way and got my phone and looked it up. All I could find was info on not doing it that way. So I call the LHBS and talk to their main guy. I tell him what I found, he opens the book and doesn't find anything about it.. Hmmm. He even said it was probably fine.

So now I'm torn.
How do I know that I should or shouldn't use sugar. It would be cheaper, easier and quicker. So of course I would like it to be true.

QUESTION:
Where is the study that says that yeast will take on these traits or have problems when being put in wort. Is this book full of it? Where is the scientific PDF that is over my head with info. I need to read it so I can sleep at night.

Thanks

I don't have the sources to back it up, but a few facts:

Corn sugar is glucose.
Maltose is a glucose dimer (glucose bound to glucose).
Yeast can only metabolize monosaccharides, so the must break maltose into glucose using an enzyme before it can used.

Non-fact based conjecture:
Will the yeast forget how to make the enyzme after a few generations of eating only dextrose? No.
Will the yeast have low stores of this enzyme if they never need to use it prior to being pitched into wort causing a lag between the time they are pitched and start actively fermenting? Probably.
Will yeast that has been using this enzyme to break down maltose have higher levels of the enzyme and start fermenting the wort faster? Probably
Will yeast fed glucose still be able to metabolize maltose? Yes
Will your beer be ruined? No

/now I'm off to find peer reviewed literature to back up my claims

*Edit
Johnston, M. (1999). Feasting, fasting and fermenting. Trends Genet. 15, 29–33. looks like an interesting read, but I can't find a free copy online. The article is summarized in this presentation:
http://www.ccbb.pitt.edu/BBSI/2007/jc_talk/genzor.pdf

Not a ton of detail, but it shows that if yeast has an excess of glucose it will signal the yeast to stop producing the enzymes needed to metabolize alternate carbon sources, such as maltose.

See now that is what I'm talking about. I will read, absord and cross ref. Thanks!
Anybody else?

There was a massive **** tossing, chest thumping thread a few months ago about using dextrose in a starter. I suggested someone do a side by side, 1 starter with dextrose, 1 with dme and compare. Don't think anyone followed up on it because of all the **** talking in the thread.

I just wouldn't do the dextrose starter, mainly because after listening to the brewstrong episode on starters, they concluded that it would work, but the yeast probably wouldn't be as healthy as they should be before pitching (i.e. enzyme reserves), which would generate a longer lag time and that by using a maltose based starter you have a better chance of getting a healthy ferment - especially when doing a high gravity beer. Now, that said, they pointed out that if you convert rice sugars, you pretty much get maltose, so that would actually work. But there are other things in DME that make it preferable for use. Listen to that brewstrong show on the brewing network, it could help answer your question more definitively.

One of my pet projects I want to do is to test this theory. I need to borrow a hemacytometer to get the results.

I'll stick my neck out and claim that corn sugar *will* work just fine *if* you supplement it with nutrients. I would recommend a mix of Fermax and Fermaid K, 1/2 tsp of each per liter of starter, since corn sugar (duh) doesn't have any nutrients. Otherwise it'd be like locking you in a room with a 5 gallon pail of sugar and a 5 gallon pail of water for a week. You would live, but you would be malnourished...

answer: just use dry yeast, and don't worry about all that stuff

I think if you want to test this, to get true results you would have to ferment the exact same beer, side by side. Just split a batch into two, and have one with the corn sugar starter, and one with a DME based starter and see how they turn out, how the fermentation goes. Because I think the arguments all surround how healthy the fermentation will be after using corn sugar for a starter. The only way to know is to do a test and find out.

Looks like I'm going to have to read a bit further into Jamil and White's yeast book... I don't remember this being in there.... stupid bad memory.

I'll stick my neck out and claim that corn sugar *will* work just fine *if* you supplement it with nutrients.

Click to expand...

Ditto

Saccharomyces said:

One of my pet projects I want to do is to test this theory. I need to borrow a hemacytometer to get the results.

I'll stick my neck out and claim that corn sugar *will* work just fine *if* you supplement it with nutrients...

Click to expand...

I think this is some good advice. The yeast prefer their food sources to be simple (most bang for the buck) so it may appear that they're just as happy with corn sugar as they would be with maltose -- but there are trace minerals and nutrients that may be missing. I'm trying to think if it would be like a human living off of sugary cereal and taking vitamins versus having a whole grain cereal right off the bat. I'll just stick with LME for the starters and be done with it. Haven't had any issues with it.

Just do it and report back. You can be the trail blazer for the rest of us.

...... When you post the thread "Why did my gravity end high" remember to reference that you made your starter using just corn sugar.

So after doing some reading and listening I will never use corn sugar in a starter and have reconsidered how I would use it in fermenting.
After listening to brew strong episode 4 of their High Gravity series, I will never add candi/corn/turbinado sugar to primary ferm. The "lazy yeast" problem can occur during fermentation and affect attenuation thus flavor. They recommend adding sugar after primary ferm is complete so all maltose have been eaten before they get any simple sugars.

We'll see! I've got a stout planned for tomorrow. About an hour ago, I set out to prep my starter and, as it happens, I'm out of DME. I do however, have four lbs of dextrose! ...and yeast nutrient! Yay?

I guess we'll see how this little experiment goes! If not, I had the same stout planned for next week so, I've got another smackpack ready to go...

Even though this thread's a little old, I went and found the page in the Yeast book. From page 23:

"It is so easy for yeast to utilize glucose that the presence of glucose actually suppresses the yeast's ability to use maltose and maltotriose." Unfortunately the book doesn't have citations within the text, but there's a load of sources in the back for the entire chapter.

I agree with some of the others that you probably won't ruin your beer. I also think some side-by-side testing is in order, but I don't think you can do this for just one generation. I'm thinking it needs to be at least 3, maybe even 5 beers deep until you can get some definitive answers. Build two starters, one made from each substance, pitch into two beers. Harvest yeast and build two more starters.

I predict that each time the dextrose-fed starters would perform a little worse. Going back to the yeast book, on page 83 there's a chart showing the SG of a beer during the period of a fermentation. The purpose of the study was to investigate what happens to yeast that are under-supplied with oxygen over the course of several batches. There are three fermentations that were measured, the 1st generation, the 3rd, and the 5th.

You can see that with each successive generation, the yeast take a little longer to begin fermentation, the fermentation proceeds a little slower, and the difference between the 1st and the 5th in terms of attenuation is an entire degree Plato.

I think this study is probably indicative of what might happen with the dextrose starter. If I learned anything from the Yeast book, it's that you need to do everything to ensure that your yeast are as healthy as possible once they hit your wort. ESPECIALLY if you plan on reusing your yeast. There's no excuse for anything less. Sure, you can make beer with less than optimal yeast, but can you make the best beer possible? And can you keep making good beer with that yeast?

With sufficient other nutrients (vitamins, nitrogen source, amino acids, minerals, etc), yeast will grow just fine with glucose as the primary carbon and energy source. Yeast biologists grow yeast all the time in YEPD, which is Yeast Extract, Peptone (peptic protease digested meat) and Dextrose and a minimal medium known as SD, Synthetic Defined (some say Dextrose). I grow all my pre-starters in YEPD, then pitch them into a DME based starter.

Lifting an old post of mine:

That said, yeast also don't get "lazy"; they switch off genes they're not using. They then switch them back on later, as needed. If later is very long, there can be some genetic drift, but that would be over dozens of re-culturing steps, if at all.

Depending on temperature, some specifics of the strain, etc. it'll take at least two hours or more to switch the relevant gene, MAL, on and have the maltase enzyme accumulate to an appreciable amount. That's two or more extra hours that your wort isn't guarded by active fermentation.

That's why you should grow in malt!

Click to expand...

kanzimonson, yeast start to perform poorly over time/generations when under-supplied with oxygen because oxygen's needed by yeast to synthesize sterols, important components of the cell membrane. They can scavenge sterols from other dead cells and trub. Give 'em some good healthy starter and, well, BAM, they're back in business. Unless someone's very unlucky*, they'd never see any change in the ability to degrade maltose. The state of the various MAL genes is independent of the fitness of the cell membrane.

*I know, I know, there's always "if it weren't for bad luck, I'd have no luck at all, gloom despair and agony on me"

That's cool stuff! It's good info like that that keeps me from deactivating my HBT account permanently.

FWIW, Greg Fix's book New Brewing Lager Beer has a great discussion on pgs 174-178. The fourish pages are alot to type out but the basic jist is that the yeast need the maltose. PM is you want a PDF of the pages.