First, I'll preface by saying that I have never used it for a starter. But I have looked at the ingredients, and based on that, wouldn't recommend it. Here are the first five.. water pure malt caramel malt high fructose corn syrup corn syrup Here are my thoughts... water - OK pure malt - Assuming it hasn't been converted to maltose, maltotriose, etc., this is not fermentable caramel malt - Somewhat Fermentable, but not as fermentable as a base malt derived sugar profile high fructose corn syrup - Simple Sugars, not recommended for a starter corn syrup - Simple Sugars, not recommended for a starter
It's because feeding the yeast high proportions of simple sugars will cause them to make the enzymes needed to use simple sugars. Essentially training them to eat simple sugars and potentially ignore or not use efficiently the higher sugars in the beer wort.
I've heard this repeated a lot but am not sure I've ever actually seen anything to back it up. Is it one of those homebrewing myths similar to "adding table sugar to your beer will give you cider flavors" or does it actually have some basis in science?
I don't know if I've ever read a paper on it, but I have heard it said by enough gurus and pros for me to believe it unless proved otherwise. I know we have a biochemist or two on here that might want to chime in.
FWIW, I looked this up in "Yeast" (White and Zainasheff) when I got home. On page 136, they say basically the same thing that I said. Not exactly a scholarly research paper, but Jamil knows a little bit about homebrewing, and Chris White knows a little bit about yeast propagation.
Interesting. I finally ordered that along with Gordon Strong's book a few days ago. Excited to check them both out.
Exactly. And within a couple of generations some yeast will totally lose the ability to ferment maltose. In the 1990's Malta contained a lot more malt and a lot less simple sugar and would have worked well; doesn't sound like the case now.
I have read this book "Yeast" by (White and Zainasheff) and also advised by my brew store that "Simple sugars will make the yeast sluggish". any way, not all your wort is pure complex sugars, so as the Goya Malta.
I just believe the ratio of simple to complex sugars is too high in Malta, certainly much higher than in beer wort. Where do you live? If supplies are hard to come by quickly you might be able to get some malt syrup from a nearby bakery (many use it instead of sugar). If you are stuck with the Malta, it will probably work ok as long as you don't plan to reuse the yeast, but if you have fermentation problems, you will know where they came from.
I've used it a couple of times. It does the job, but I would not recommend it. It discolors the beer and (maybe it is my imagination) I could swear it contributed some funky flavors. Mostly just not cost effective.
FWIW: I just read this a few hours ago in Palmer's "How to Brew" book. p75. "Yeast that have been eating a lot of sucrose, glucose, and fructose will quit making the enzyme that allows it to eat maltose - the main sugar of brewers wort."
I find it highly suspect that conditioning yeast to metabolize only simple sugars would prevent them from reverting to a state where they could metabolize more complex sugars. Yeast are very resilient and resourceful organisms and there is no reason they wouldn't begin to make the necessary enzyme when exposed to complex sugar sources. This would perhaps delay the metabolism of complex sugars just a touch (though it's hard to know if it would even be a noticeable or measurable difference). I wasn't able to find any relevant scientific work but it may be out there. Interesting topic though.
A google search for "inhibition of yeast maltose metabolism by glucose" turns up a bunch of published papers on this topic. As a resident grumpy biochemist on this forum, heres a link to a review article ( http://www.ftb.com.hr/42/42-213.pdf ) that answers the question (specific data in references)... In short, glucose represses the genes (Six I believe) responsible for maltose metabolism and transport (General inhibition phenomenon aka Catabolite repression), and also regulates their degradation at the protein and mRNA levels (mal62 & mal61 mRNA). Two things worth noting, allelic variants of the genes responsible for maltose metabolism (e.g. strain dependent variants) as well as constitutively active (e.g. on all the time) genes for maltose metabolism/transport can have a large effect on the efficacy of glucose repression. A more detailed description is available in the paper, but I'm too tired from dealing with broken SPR machines at work to recapitulate it. One other thing, worth noting, in metabolism involving genes, proteins and small molecules is incredibly complicated, with shitloads of feedback loops, repression, activation, modifications, etc. etc., so much so that a human can't accurately predict what a cell or metabolic pathway will do under specific conditions, which results in the need to generate mathematical models and computer simulations to accurately predict outcomes (Which we still aren't doing all that well), so, while we can identify the specific effects in simple systems or under very specific stimuli/conditions we can't always predict exactly what will occur with the system in its entirety. So...... In short, I probably wouldn't use Goya Malta to make a starter.
How much does a pound of Goya Malta typically cost? Would it even be cost effective to use in place of DME?
From that paper: "The maltose metabolism in S. cerevisiae is under the control of three general regulation mechanisms: induction, glucose repression and glucose inactivation. The presence of maltose in the cell environment is necessary for the induction of synthesis of maltase enzyme and maltose transporters. The carbon source on which yeast was precultivated does not influence the induction rate (6). With the addition of glucose into the maltose medium, total inactivation of maltose transport system occurs in 90 min (7,8). During that period maltase activity remains almost unchanged. When the cells are shifted back into the pure maltose medium, fast regeneration of maltose transport system is observed (in approximately 1 h)." This would suggest two things to me: if glucose is present, maltose uptake is nonexistent (so any media with glucose would inhibit maltose transport - malt extract can have up to 10% I believe?). Secondly, the time for maltose transporter regeneration is relatively inconsequential (1h). Believe me, I understand that signaling pathways are incredibly complicated and it is hard to predict outcomes as I am also working with them (though mainly mammalian - others in my lab are working on sacch c).
With all due respect, I think you are trying to disprove the theories of evolution here. Not disagreeing with the idea that yeast will eventually resort back to creating the necessary enzymes to break down longer more complex sugar strains, but I don't think that will happen over night in time for the batch of beer to get optimum results. Basically yeast gets lazy...if you had a fridge filled with prepared food or ingredients to prepare food, which would you eat first? And once you were full, would you start preparing those ingredients in the fridge if all the prepared food was gone? Basically more strains will flocculate before they get to that point and you will end up with a sweet beer! Again, no disrespect, cheers!
Well, I am really talking on a protein expression timescale, not on an evolutionary one. If you talk a look at my previous post, an excerpt from the paper barfdiggs posted claims that it takes about 1 hour to reconstitute the maltose transporter proteins that are required for maltose uptake (and ultimately metabolism, though those proteins do not actually execute the breakdown of maltose).
I'm inclined to believe this based on personal anecdotal evidence. I've brewed plenty of beers with simple sugar additions (up to 10%+ of the fermentables) and have very rarely had problems reaching desired FG.
That's a small proportion with tons of non-simple sugars about... I suggest you read up on mead production and how to get it done.
My biggest simple sugar addition was in a Duvel clone, which was about 1/3 simple sugar. That beer reached an FG of 1.005. If the yeasts will metabolize glucose first (as cited above) then they are definitely capable of continuing to metabolize maltose pretty efficiently afterward, based on my experience. I'm definitely no scientist though. I'm just reporting what I've personally observed. I guess what I'm trying to say here is, what is the difference between malta goya and a beer with a relatively high percentage of simple sugar in the wort? Does anyone know what percentage of malta goya is maltose?
If your yeast are nice and healthy, and are low to medium flocculating, then it will clean up shop...but we are talking about yeast starters here, not just recipe additions. If you brew a braggot with a crap ton of honey, the yeast will eat.the honey first because the sugars are so simple...if they are still hungry and in suspension after that, they will eat the more complex sugars, but if not your batch could get stuck.
I am also curious to know what the OG of goya malta is. Here it is claimed to be 1.060: http://www.thebrewingnetwork.com/forum/viewtopic.php?f=7&t=8090&start=10 You'd want to dilute it down to get a 1.030-40 OG starter.
Yay! Now I can do the "is it cheaper" math. 1 gallon of goya malta would cost $7.25. (128 oz/gallon / 12 oz/bottle * 0.68 $/bottle), yielding a wort of 1.060. To get 1 gallon of 1.060 wort you would need approximately 1.33 pounds of DME (assuming 45 ppg) which costs about $6 (based on Northern Brewer's $4.50 a pound). If buying in bulk it is much cheaper ($2.70 a pound if you buy 50#). So at a minimum Goya is 20% more expensive! Of course this completely ignores shipping costs, sales taxes, bottle deposits (all where applicable), time & convenience.
I used it only because I wanted to make a starter but was out of DME, and the bodega down the street had Malta Goya. It worked fine. By that I mean that the starter acted normally and the beer came out without any off flavors. (I decanted before pitching.) In my mind it was better than no starter. So, based on this experience, I'd say it could be used in a pinch. But I certainly haven't made it a practice, nor do I plan to do so.
D Ditto. I've used it here and there with no ill effects. Not my first choice in most cases, but it's preferable to no starter at all.
I had what I thought was a pack of bad yeast a while back. Typically I just pitch straight in for low gravity beers, but I wanted to be assured of viability so I pitched the night before in Malta Goya. Needless to say, it worked and the beer turned out great but it was just 12 ounces of Malta Goya to get the yeast roused.
I think there is a big difference between using a healthy pitch of yeast in a wort composed of 10-20% simple sugars and actually propagating yeast in a starter wort composed of mostly simple sugars.
Not saying there isn't, just asking the question. Specifically, does anyone know the percentage of maltose in malto goya? Definitely not advocating that people use it regularly, but it could work in a pinch if you need to make a starter, you're out of DME and the homebrew store is closed.
My buddy and I have been using Goya Malta for a starter a long time now. We start six or seven days before we brew with either a 7oz. bottle or a 12oz. bottle each day. Also, we brew from 20 to 60 gallons at a time. And never had a problem!
