Yeast Starters

[Carnot]

After making my introduction I was asked to explain my yeast starters using honey. Here we go

After reading Ken Scrhamm's book on mead he made a comment about yeast starters and I followed this up with other research and it struck an accord. I wanted to avoid boiling the must for mead making and a strong vigorous starter is essential.

My starter is nothing special. I add 200 g of honey( I have several types available) and make it up to 1000 ml in a conical flask. This sits on a magnetic stirrer ( available on eBay) and is stirred vigorously. Add the yeast ( about 10g per 20-25 lts and about 2 g of Fermaid K and watch is explode. It takes about 12 hrs to really get going and can then be pitched into the must. I have done this with all my brews.; ale , cider and mead. It does not fail. The yeast is so strong that it crowds out any other invaders. I prepare the yeast the day before pitching and at the same time I work up the must / beer wort. Overnight I allow the must to cool to room temp and add about 2 g per 25 lt of potassium bisulphite to prevent infection. This is the only time I use sulphites. The next day I pitch the yeast and it always results in a vigorous fermentation. I add around 2-2.5 g Fermaid K to the must on pitching.
The rest is textbook.The honey gives a noticeable twist to the flavour/taste of the beer and the cider. For the mead it just get better with time. Mead does require a lot of racking. Eventually it all ends up in Corny kegs (cider, mead, beer) I have many (40+) of them and cannot recommend them more highly.

[Jambo]

Interesting info, thanks, and certainly makes sense for pitching into mead.

However most of what I have read would suggest that firing yeast up with the enzymes to ferment honey (glucose and fructose) and then pitching into an ale (maltose etc.) wasn't best practice by any means?

Anyhoo I look forward to reading more of your posts, I took up beekeeping myself this year and I'm hooked! Hats off to anyone who can make it break even never mind profitable.

[Wonkydonkey]

intresting read, on starters with fermaid k and honey, this year ive gone fullon making cider, but I really have just let it do its thing with the wild/fruit yeast. i have nearly 200lt apple juice in about 8 vessels, some ive added honey from washing the wax cappings. we will see how they turnout. some time will be needed for sure, and I can see some blending happening.
btw, im a beekeeper
cheers

[McMullan]

Yeast prefer simple sugars like glucose. It's us beer drinkers who prefer malt, where about 50% of the sugar is maltose. The idea that yeast lose any ability to metabolise maltose after being cultured in any media not containing maltose is a myth peddled by 'blog wisdom'. We shouldn't be so superstitious as Brewers. There really is no need these days.

[Kev888]

Regular brewers often have access to free or cheap wort, such as saved from the last runnings of the previous batch. But if you have to buy malt extract (or similar) to make starters then using other media does seem more attractive - both for price and for not having to deal with DME (which is something I personally dislike).

If you pitch the whole starter then something with reasonably desirable flavours may be beneficial. But I'd be interested if anyone knows what nutrients etc would need to be added to even plain white sugar to make the yeast as happy as possible - are any of the commercial homebrew offerings complete/sufficient?

[Jambo]

Yeast prefer simple sugars like glucose. It's us beer drinkers who prefer malt, where about 50% of the sugar is maltose. The idea that yeast lose any ability to metabolise maltose after being cultured in any media not containing maltose is a myth peddled by 'blog wisdom'. We shouldn't be so superstitious as Brewers. There really is no need these days.

McMullan I'm also against going with superstition and blog wisdom, but I didn't get this from a blog.

P136 of Yeast by Chris White: "Use all-malt for starters. The sugar in the starter needs to be maltose, not simple sugar. Yeast grown exclusively on simple sugars stop making the enzyme that enables them to beak down maltose. Since brewing wort is mainly maltose, fermenting it with yeast grown on simple sugar results in a beer that will not attenuate properly."

That said, I don't mind a beer with plenty of residual sugar! And the wild yeasts abundant in raw honey may make for interesting character. The point another poster made about nutrients is also important if the amount of nutrient specified in mead recipes is anything to go by.

[McMullan]

Glucose represses synthesis of the enzyme 'maltase'. Once pitched into wort (containing maltose) yeast cells produce maltase, unless dysfunctional cells were selected for in the starter, to dominate the population, which is unlikely, even if starting from an individual yeast cell/colony. I can only assume Chris White is recommending all malt because it contains sufficient nutrients for culturing yeast for fermenting batches of wort. If the required nutrients are included in a simple non-malt sugar media, the yeast ferment wort downstream without any issues.

[McMullan]

Regular brewers often have access to free or cheap wort, such as saved from the last runnings of the previous batch. But if you have to buy malt extract (or similar) to make starters then using other media does seem more attractive - both for price and for not having to deal with DME (which is something I personally dislike).

If you pitch the whole starter then something with reasonably desirable flavours may be beneficial. But I'd be interested if anyone knows what nutrients etc would need to be added to even plain white sugar to make the yeast as happy as possible - are any of the commercial homebrew offerings complete/sufficient?

Yeast extract (the nutritious contents of dead yeast cells) and peptone (free amino nitogen source) are commonly used in lab based media. The 'complete nutrients' offered by WL and Wyeast should work, but ignore the recommended dosages for nutrient-rich wort. Add a lot more.

[wessexwyvern]

The "blog myth" probably comes from studies that showed that in worts containing 30% sucrose as an adjucnt, the fermentation of maltose was severly repressed or a large percentage of it didn't ferment at all.

[McMullan]

The "blog myth" probably comes from studies that showed that in worts containing 30% sucrose as an adjucnt, the fermentation of maltose was severly repressed or a large percentage of it didn't ferment at all.

Sounds like the yeast might have experienced a 'sugar rush' and gave up before finishing the second course. Did they dilute wort with additions to control for initial gravity? Also, this sounds like a fermentation experiment, not a culture/starter experiment.

[wessexwyvern]

It was a controlled fermentation experiment. The enzymes that utilise maltose are effectively switched off. As per our previous discussion I was unable to find out if it was a permenant state of affairs. However less biomass is produced in sugar. Just pointing out that there is substance to the myth, even if it was a misunderstanding..

[McMullan]

It was a controlled fermentation experiment. The enzymes that utilise maltose are effectively switched off. As per our previous discussion I was unable to find out if it was a permenant state of affairs. However less biomass is produced in sugar. Just pointing out that there is substance to the myth, even if it was a misunderstanding..

The genes coding for particular enzymes are 'switch off' when they're not required. Under favourable conditions they’re 'switched on', if the substrate becomes available. Reduced biomass is usually a sign of nutrient deficiency, not the type of sugar substrate. Yeast cultured on dextrose-based media agar (slants), stored for months then grown in dextrose-base media ferment wort without any issues.

[Jambo]

I can only assume Chris White is recommending all malt because it contains sufficient nutrients for culturing yeast for fermenting batches of wort.

I think the quote I put above clearly shows his reasoning is enzyme related, although he does talk about nutrients too.

Don't get me wrong, if I can stop paying for and messing around with DME I'll be delighted to do it, but for now I'll go with White.

[McMullan]

Perhaps you should challenge him for some convincing evidence. If I made such statements in a book, I'd be sure to supply a reference, to avoid any blame at a later date, if for nothing else

I think I know more about enzymes than Chris White, TBH.

[Jambo]

Perhaps but I won't because I don't have a direct line to him, don't have any knowledge on which to base a disagreement with him and, crucially, can't be arsed!

Is there a more accurate book you would recommend on yeast?