Basics Of Making And Using A Yeast Starter

[Wolfy]

A yeast-Starter is a small volume of wort used to increase yeast health and to grow yeast cells before pitching.
Please do not be put-off by the fact it took me 3 posts to explain the utterly simple procedure of making a yeast-starter (just read the bold bits and look at the pictures if you like). All it is is a small quantity of wort that is used to grow liquid yeast and increase the yeast health before pitching. If you can make beer you can make a starter, in some ways a starter is even easier than brewing good beer at home.

You do NOT need to use a starter if you are using dry-yeast, starters are only useful for liquid yeasts and then only if you need to increase the yeast health or cell count. If you have newly-manufactured packs of yeast, they should be good to pitch into 5US gallons of standard gravity wort, if you have more wort, higher gravity wort, if your yeast pack is more than a week or two old, or if you are growing yeast from a slant/slope or from bottle-harvested yeast, a starter can be very useful or even essential.

The usual size for a (Ale) starter is 1L to 2L.
If you are making a starter from a packet of freshly opened and recently manufactured pack of commercial liquid yeast the MrMalty calculator or the Wyeast version will give a very good indication of what is required.

The gravity for a starter should be between 1.030 to 1.040, if your yeast is old and tired a lower gravity can help, even if you are making a high-strength beer, the starter gravity should still be within this range.

A starter should be made from malt (or malt-extract) do not use sugar or other adjuncts, where possible keep the starter wort similar to that of the beer you will pitch the yeast into. Starters do not need to have hops added, you can add hops, or use pre-hopped wort, but it is not essential or even that useful.

Most often starters are made from DME.
Mixing LDME at the rate of 100g per 1L water will give the required gravity.

If you have it, add a pinch of yeast-nutrient or a pinch of old yeast (that will be boiled and turned into nutrients for your yeast):

Liquid malt extract, even out dated tins of hopped extract also makes a good starter, however you do need to learn how much to use:

(I find that about 2 heaped teaspoons is a good quantity to use)

If you brew all-grain, you can save the last runnings from the mash-tun, then boil them down in a saucepan to give the required gravity.
After cooling, let the break settle out and decant the clear wort into your starter container:

Or you can collect the residual wort (and hops and break material) from the bottom of the kettle after boil.
Let it sit for a while so the break and hop debris settle out and then decant the clear wort, before adjusting to the required gravity:

 

[Wolfy]

The starter wort and container should be as sterile (or at least sanitized) as possible. Ideally both the wort and container should be autoclaved, but in most cases boiling for at least 15mins is sufficient, if you are unable to autoclave or boil your starter-container sanitize it chemically as best you can, any bugs or infection in the starter will be propagated into your beer.

Starter wort should be boiled for at least 15mins, if possible you should do that inside the starter container. Otherwise, if possible boil the wort in a saucepan and add it to the container while still boiling hot, else if you use plastic containers, boil the wort and let it cool before tipping it into your starter container.

Any container of an appropriate size that can be easily sealed and easily shaken or stirred can be used.

Plastic PET soft-drink bottles make useful and cheap starter containers.
However, since they cannot be heat-sanitized, chemical sanitizers (bleach, StarSan, Idophor) must be used and starter wort needs to be boiled and then cooled in another container - while this works it is less than ideal.

Since glass jars and bottles can be heat treated (and even autoclaved) they make a much better starter container.
If you have an autoclave or pressure cooker big enough (I do not) the starter and container can both be sterilized.
Otherwise the wort can be boiled and then poured into the glass container. I soak the glass bottles shown below in a sink full of hot-tap water to raise their temp, this has allowed me to fill them directly with boiled wort without breaking them (this may or may not work for you, please do not do anything dangerous or silly or hurt yourself or others).
Adding the wort to the container while it is still boiling helps to ensure that everything is sanitized well.

Plastic PET bottles, glass bottles and jars can easily be capped and shaken to help improve the yeast health and growth. By using an over-lay of cling wrap (as shown in the pictures above) you can open the bottle to release the CO2 build-up, but also seal the bottle to shake vigorously without exposing the starter to risks of contamination.

However, the best starter containers are those made from borosilicate/lab glass. These can be directly heated, boiling and sterilizing the wort and the container at the same time, this greatly reduces the chance of infection and means you do not need to rely on chemical sanitizers:

Lab flasks with flat-bottoms also allow for the use of a stir-plate which can also help increase yeast cell growth.

Starter-containers do not need an airlock, cling-wrap, aluminum foil or a lid works well, as long as bugs and contaminants cannot get into the starter that is what matters most.

 

[Wolfy]

The starter should be kept at comfortable room temperature (low/mid 20degC) if you are comfortable the yeast will be comfortable, higher temps will cause the yeast to grow more quickly, but also increase the risk of mutations, colder temps are not as useful for good yeast growth since it slows their metabolism.

The starter should be aerated (shaken or stirred) on a regular (ideally constant) basis, this provides the yeast oxygen required for growth and helps degas CO2 which can inhibit growth and health:

Yeast growing on my DIY stir-plate, it is usually covered with a tea-towel so that the cat does not find it so interesting and to keep out any dust or airborne contaminants.
If you do not have a stir-plate try to put your starter in a prominent location where you will remember to shake it on a regular basis, you will get more yeast growth and better yeast health if you shake the starter very frequently.

Making a starter is all about growing a quantity of healthy yeast ready to pitch into your beer. The conditions - in particular temperature, wort and aeration - are designed for good healthy yeast growth, NOT for making good tasting beer, which would often be done at lower temperatures and not aerated.

Yeast cell growth should be completed after about 24-36 hours, the starter does not need to ferment out fully before you can pitch the yeast, you are just looking to grow a quantity of healthy yeast.

Once the starter is complete, you can either:
Pitch the yeast at high krusen, since the yeast is most active at this time, some people like to pitch it into their beer. This means that the entire starter is pitched into your beer, and the starter wort should be similar to the beer-wort or else the yeast might need to acclimatise.
... or ...
Wait for the starter to ferment out fully, let the yeast settle, decant the spent starter beer and pitch only the yeast. This pitching method means you can pitch only the yeast, minimizing any off-flavours in your beer that may have been introduced by the starter. Allowing the yeast to fully ferment the starter and then settle (often with refrigeration) adds more time to the starter process, but it also allows the yeast to build up reserves so that they can acclimatize quickly and easily when pitched.

 

[Nevalicious]

Do you realise just how many old and new brewers out there this is going to help Wolfy. Bloody well done mate. I've always found your posts on yeast related stuff (of which there is heaps) to be so helpful...

Awesome work mate

Nev

 

[ianh]

Thanks Wolfy great tutorial, nice collection of yeasts you have.

cheers

Ian

 

[petesbrew]

Nice one wolfy.

 

[bignath]

Wolfy, i am just about to start my first foray into using liquid yeasts and i've been trying to get my head around all this stuff recently.

I brilliantly written article, and it couldn't have been timed better for me!

Cheers mate,

Nath

 

[keifer33]

Good stuff Wolfy will definetly be using this regularly as I'm only just moving into the world of starters.

 

[argon]

ahem... yeast sub-forum... ahem h34r:

Nice work Wolfy good info as always

 

[bignath]

ahem... yeast sub-forum... ahem h34r:

+1 Top Idea!

(we all know lots of posters have mentioned this before, particularly in things like "how would you improve AHB threads" and similar. would love it to come to fruition.)

 

[outbreak]

These pictorial how-to's are great. Thanks!

 

[proudscum]

made a quick climate control box for my yeast as its a bit cool in my lab area(has a laugh to himself)Used a 55lt esky temp control for heating and an old brew pad.Sat on a nice cosy
20 oC and both flasks are ready to go through the settling period before being used on Friday and Saturday.

Quick simple and using up things sitting around not being used.

 

[manticle]

Making a starter is all about growing a quantity of healthy yeast ready to pitch into your beer. The conditions - in particular temperature, wort and aeration - are designed for good healthy yeast growth, NOT for making good tasting beer, which would often be done at lower temperatures and not aerated.

..........


Once the starter is complete, you can either:
Pitch the yeast at high krusen, since the yeast is most active at this time, some people like to pitch it into their beer. This means that the entire starter is pitched into your beer, and the starter wort should be similar to the beer-wort or else the yeast might need to acclimatise.
... or ...
Wait for the starter to ferment out fully, let the yeast settle, decant the spent starter beer and pitch only the yeast. This pitching method means you can pitch only the yeast, minimizing any off-flavours in your beer that may have been introduced by the starter. Allowing the yeast to fully ferment the starter and then settle (often with refrigeration) adds more time to the starter process, but it also allows the yeast to build up reserves so that they can acclimatize quickly and easily when pitched.

Wolfy - great post and pictures.

One question though: If pitching the entire active starter in as I usually do, the first point about conditions not being needed to make good beer (temp aeration etc) is less so as far as I understand. I believe if you pitch 2 litres of oxidised estery beer into your wort, those flavours can transfer to the final product.

I treat my starters with vigorous shaking until krausen appears, then leave it alone at roughly ferment temps.

 

[corcatraz]

Good shit wolfy. Appreciate this!

p.s. I think the worcestershire sauce is ready for the bin :icon_cheers:

 

[HeavyNova]

Thanks for the info and pics Wolfy - also very good timing for me as I'm thinking about getting into this soon too.

Interested in Manticle's question too...

 

[MeLoveBeer]

If you brew all-grain, you can save the last runnings from the mash-tun, then boil them down in a saucepan to give the required gravity.

Have been toying with this idea for a while, but have been worried about the ph of the last runnings and its effects on the yeast; what are your thoughts?

p.s. Solid work putting this together :icon_cheers:

 

[manticle]

Alternatively just take a litre or two from the wort once you've finished draining the tun.

Can dilute to 1035-1040 if it's a big beer although I rarely bother.

 

[felten]

One question though: If pitching the entire active starter in as I usually do, the first point about conditions not being needed to make good beer (temp aeration etc) is less so as far as I understand. I believe if you pitch 2 litres of oxidised estery beer into your wort, those flavours can transfer to the final product.

I'd say there's definitely a difference between the two.

When building up the numbers you want the agitation and oxygen exchange to feed the yeast, and you want to let it run for 24-36hr so that after the yeast are done with their growth they have time to build up their glycogen reserves, of course though this usually doesn't result in a tasty beverage but that's not the point.

If you are just getting the yeast visibly active before pitching then you want to keep the temperature and aeration the same as you would for the main ferment so you don't build up those off flavours (or temperature shock the yeast when pitching), but you also won't get near the same amount of yeast growth as a fully aerated/fermented starter.

I know you separated them out already Wolfy, but it is a different beast imo.

 

[adryargument]

Great thread, however the iamge of your flask on a stove with alfoil brings bad memories. Did the same thing the other week and ended up with 120 degree water all over the ceiling and floor. Nasty burn to! Needs a warning!

 

[Dave70]

Great stuff mate.

I'm a visual learner, so the pics really help.

I think specific 'how to' posts like this should be stickied - or at least sub stickied somewhere.

Can we expect ' Trouble shooting tips for a non bubbling airlock' thread any time soon? That issue just gets swept under the carpet to often for my liking..