brewing question about yeast and alcohol percentage

I find yeast packages expensive these days.
is there a way to take half a dry yeast package and grow it into enough yeast that you need to pitch. sort of what they do in big breweries? Is there a name for this technique ?


second question: in beer brewing how do they increase the alcohol percentage?
is it just adding more malts ? but thats more sugars.
example there's some beers I like that are 6%. how do they achieve this ?


Thanks everyone

Yes to the yeast question. Make a starter and grow the yeast cells on.

There are many things things that can increase abv. Sugar, lme, dme, more grain. Depends which method you use and what flavours etc are you after

Well, I guess �£2.50 for a packet of yeast might be considered steep for 25l of beer. If so, as Leon suggests, make a starter. Make a big one & you can start a few beers off in one go. Loads of info on this - search here or Google it. Also, harvest yeast from your brew & re-use. Again. this is a well-discussed topic.

How to increase the alcohol? Yep, just add more fermentables (well, up to a point - you can't ferment to whisky strength!!!)
I'm guessing you're using a beer kit. Well, the simplest way to make it stronger is just to add table sugar. That won't make it taste any better, though. So - more expensive, but better result - is to use dried malt extract to boost your beer's alcohol content whilst also maintaining well-balanced flavour.

Personally i wont scrimp on the ingredients, as homebrewing for me is trying to achieve quality at a much reduced cost. But not so much that it compromises flavour, as there would be nothing worse than having 40 pints of ****e beer to drink. I aim for my brews to cost around £25 which includes kit/yeast/dme and any other bits. This gives a pint at 62.5p which is still a lot less than what you can buy commercially.

huxley001 said:

I find yeast packages expensive these days.
is there a way to take half a dry yeast package and grow it into enough yeast that you need to pitch. sort of what they do in big breweries? Is there a name for this technique ?


second question: in beer brewing how do they increase the alcohol percentage?
is it just adding more malts ? but thats more sugars.
example there's some beers I like that are 6%. how do they achieve this ?


Thanks everyone

Click to expand...

The technique is called stepping up, we do it at various times like culturing yeast from a bottle or reviving an old culture. Also for high gravity beers when we need a bit more yeast than normal.
It's not normally done with dry yeast though, mainly liquid.
Dry yeast (gram for gram) has a much higher cell count and generally only needs rehydrating before pitching. Personally I'd save making starters for using liquid yeast as dry yeast packets are so cheap (sometimes only a quid or so) that if you want to pitch more just use two packs.

Increasing the abv is simply a case of increasing the fermentables, there are many ways as mentioned above.
Personally, when getting to 6% and above I'd start thinking about simple sugar additions as all malt wort at high gravities can get a bit cloying.

As Mentioned above there's cheap and there's cheap... If you are trying to cut the price of your homebrew by splitting packs of dried yeast I'd be wary. We can make much better beer than you'll get anywhere else at a fraction of the cost, so further cutting costs as you suggest may not be a really clever saving.
I use the best ingredients I can get including liquid yeast at 3-4 times the cost of dried. But by culturing up and splitting batches means it actually works out cheaper than using dried yeast.
There are better ways to make it cheaper to produce beer in my opinion.

To spread the cost of the yeast I make one brew using the full packet of yeast, then when I bottle it I save the yeasty trub from the bottom of the FV and do a second brew - 2 or 3 table spoonfulls of the trub gets the second brew off to a flying start, and before anyone asks, I haven't noticed any deterioration in the quality of the beer produced. I wouldn't do this a second time though as I guess that would be when you'll find out just how good your sanitizing is.
Of course if you wanted a third brew from a packet of yeast, if you've got 2 FVs, then after the first brew you could use the trub to start off 2 new brews at the same time.

In terms of increasing the alcohol, this can be influence by the choice of yeast. Different yeast strains can munch through more more or less of the fermentable sugars which will have an effect on the alcohol in the beer and also the residual sugar left behind.

Something like US-05 or Nottingham will get about 80% attenuation meaning there you would get a stronger beer than if you used something like Winsor which gives closer to 65% attenuation and leaves a weaker sweeter beer as a result.

The other way to get cheap yeast is to harvest it from bottle conditioned beers. I've just had my first go at this and have cultured up a starter from Young's London Gold.

Assuming you are happy to buy a couple of bottles of beer which you get to drink , the only other cost is a bit of dry malt extract to make the starter with.

Hi all,
The main bearing on yeasts' ability to munch through sugars is to do with its' ability to tolerate alcohol, rather than the type of sugar present due to mashing protocol. Some yeasts' even in the presence of simpler sugars will give up the ghost at certain low ABVs.

In answer to the OP, 'propagation' is the correct term for growing yeasts in breweries. This is done on a regular basis to keep the yeast strain in the correct proportions if they use a multiple strain culture (most do) to stop one strain dominating. They may have one strain for flavour reasons, another for fermenting capacity. If a beer they produce is higher in ABV, it may favour one strain, therefore this one will flourish, but they will lose flavour and vice versa. Therefore, periodically they will retain the balance by repropagating.
Barley wines were produced with and ale yeast initially, up to about 6%ABV, they therefore had the typical beer flavours in the form of esters and the like, but was reinoculated with a wine yeast as the ale yeast had given up. This increased the ABV, it was primarily more tolerant of alcohol, as the extra OG was generally got from invert (simple) sugars, rather than its ability to ''munch" through complex sugars, as the resulting final gravity was proportionally higher anyway, and therefore not digested anyway.
WBR
Hoppy

thanks for everyone's help. I appreciate it.

Hoppy said:

Hi all,
The main bearing on yeasts' ability to munch through sugars is to do with its' ability to tolerate alcohol, rather than the type of sugar present due to mashing protocol.
Hoppy

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Gosh, this is virtually the opposite of what I've come across so far. I thought that my mashing temperature was critical - low temp equals a lot of readily-fermentable sugars. I'd read that higher temp gives a trend towards bigger sugar molecules that beer yeasts can't ferment so you get a sweeter, or heavier-bodied product.

From what you say, I'm totally wrong about this.
Can you explain further - I'd love to know what's really happening in my beer :)

Hoppyland said:

Gosh, this is virtually the opposite of what I've come across so far. I thought that my mashing temperature was critical - low temp equals a lot of readily-fermentable sugars. I'd read that higher temp gives a trend towards bigger sugar molecules that beer yeasts can't ferment so you get a sweeter, or heavier-bodied product.

From what you say, I'm totally wrong about this.
Can you explain further - I'd love to know what's really happening in my beer :)

Click to expand...

To answer your original post...
I just got some 11g packets of yeast out of the fridge.
Safale us-05 says "11.5g in 10 to 30 litres"
Safale s-04: ditto
GV12: says nothing.
So, the inference I take from that is you could split a packet of dried yeast between brews if you chose. I wouldn't keep it long once the packet was opened though.

Beer isn't usually strong enough for the alcohol content to affect the yeast, the limiting factor is the amount of fermentable sugar. Some strains of yeast are more flocculent than others so may sink to the bottom before all of the fermentable sugars are used up. For example, s-04 attenuates 75% compared to Mangrove Jack m10's 85%.

Mash temperatures can be adjusted to affect the sugars available in the beer. Plenty about it if you search.

HebridesRob said:

Beer isn't usually strong enough for the alcohol content to affect the yeast, the limiting factor is the amount of fermentable sugar.

Mash temperatures can be adjusted to affect the sugars available in the beer. Plenty about it if you search.

Click to expand...

Well, yes this is what I'd always understood - and my own brewing experience seems to bear it out. But the post by Hoppy sounded very authoritative - I just wondered if I was missing something. New information always welcome! :smile:

You can re-pitch from your trub three or four times without issue and this will cut your yeast cost down. I keep it simple I fill a sanitised bottle a third full with trub which you can refrigerate for a week or so but I use it within 24 hrs so I leave it at room temperature. When your new wort is ready fill the room temp bottle of trub with wort, give it a shake and then pitch it into the FV. Mine have always gone off like a rocket. To bring up your ABV you can add a tin of Lyons Golden Syrup or 50-60g of honey and you'll get about 6%. I just mix them with boiling water and stir them into the FV.

Hoppyland said:

Well, yes this is what I'd always understood - and my own brewing experience seems to bear it out. But the post by Hoppy sounded very authoritative - I just wondered if I was missing something. New information always welcome! :smile:

Click to expand...

You are correct in saying that mash temperature has the effect of determining the level of fermentable and non fermentable sugars. Once you have these sugars then the yeast plays it's part with some yeasts more attenuation and some more tolerant of alcohols than others.

it is a two part process to obtain the sugars for teh body and mouth feel you want and use the correct yeast to produce flavour and alcohol that is required. If you are producing low ABV ( 4-6%) I think most yeasts would be tolerant of this range.

Hi Hoppyland,

Sorry for the late reply, geetee has beaten me to it! My point was, that even if you had a low temp mash and even used an enzyme to produce a simple sugar rich wort, rather than complex sugars, depending on ABV, above 6% generally, the yeast will slow due to the presence of alcohol.

Yes, mash temperature does influence the sugar profile, (heat denatures one of the enzymes that breaks down sugar), but not quite as much as you think, as pH also serves to create a stable environment for this enzyme to survive longer into the mash. This enzyme, even at lower temps only really survives an extra 5-10 minutes into the mash (from about 20mins), before it is denatured by heat.

This is the reason you reduce the alkalinity of your brewing liquor (by adding acid), to adjust the pH for this enzyme to survive. This is why commercial brewers, who have slightly differing specs for the pH of their liquor, have slightly different mash temps for similar results.

Producing a slightly thicker mash can help preserve these enzymes too as the grain is more slowly re-hydrated and in turn heated.

Do all of these and you then really change the characteristics of your sugar profile.

WBR

Hoppy