Why not just use yeast nutrient and table sugar for a starter? I have heard about the esters etc... produced by using excess table sugar in recipes. My thought is that since you are pouring off the fermented wort and just pitching the yeast you could just use plain table sugar as your food for colony growth. This would have been a great question for Chris White.

The problem you face homegrown, is that the yeast will get used to the sugar very quick, and when it comes time to pitch into your wort they will tell you to F off, because sugar is easyer for them to feed on, remember that the yeast has already been grown on malt, what ever way you get it, its grown on malt, then if you introduce it to a simple sugar it will mutate slightly to feed of that, but it wont like comming back to malt

I like your arguement Oz, but would be interested to see if there is data to support the theory. While there is chance for some mutation in the time that cell growth will take place, it may be improbable that the genome would be changed enough to affect fermentation. I'll see what my genetics professor thinks about the matter when I see him next. There is a shitload of research info from yeast.


Cheers,
HH

Oz is right. It's not a genetic mutation, though, but an adaptation. Sucrose is made of glucose and fructose. Maltose is glucose and glucose. Yeast need to produce different enzymes to break the sucrose molecule into its component parts than they do to break up a maltose molecule. Invertase breaks down sucrose while maltase breaks down maltose. Yeast can make either of these depending on their environment, so it's a matter of timing and what they are used to eating when you pitch them.

If you grow a starter in sucrose the yeast will love it and multiply. But they have no way of knowing that you plan to eventually toss them into a maltose wort. They are busy building resources for their current environment, so they will have tons of invertase ready to use, but stop making maltase altogether. So when you do finally toss them into the wort without sucrose, they can't eat it until they change their metabolisms and make maltase. Depending on the individual cell's energy reserves, some may not be able to make this change in time and can actually starve to death in a sea of sugars. Most of them probably survive, though. You just get a longer lag time while they ramp up to eat maltose and stress the hell out of your yeast.

OTOH, if you make a malt starter, the yeast have never been exposed to sucrose and will build up reserves of maltase. So when you pitch them into the wort, they're primed and ready to start eating it and ferment your beer.

AFAIC, you're better off pitching a smack or tube directly than making a sucrose starter.

George,
Thanks for the information, your explaination makes perfect sense. I probably would have run across that information if I had done some research before posting. I had no doubt that Oz was correct(or close enough) but your explanation hit it home. I had a feeling that there was sufficient reason to not use sucrose or the pro's would be using it to reduce cost of yeast.

Thanks guys,

HH

I'm a cheap SOB too. But instead of sugar and nutrient, I just batch sparge a pound of malt in a 1 gallon drink cooler and do a 30 minute boil on the stove. I figure if I have enough grain to brew, I have enough grain to make starter wort. I am doing this a couple days ahead of time so it doesn't add time to the brew day. Heck, it doesn't really even cut into my beer drinking time. I can still drink beer, watch tv, post to this forum and make starter all at the same time. Doesn't take paying as much attention as when you actually brew.

Wayne
Bugeater Brewing Company

Thanks for posting this bug, this was actually my other option aside from using high dollar DME. I suppose making a 5 gallon mash for starters every so often will be in my schedule from now on. I will put them in gallon jars and pressure cook them instead of boiling them and saving though.


Cheers,
HH