Yeast Start w/extract kit & Stir Plate?

[jwetzler]

I have a few extract kits under my belt now, and am wanting to start wading out to the deep end of brewing a little more...slowly lol.

I am subscribed to weekly emails from Beer Smith, and recently received an email talking about the benefits of using a Yeast Starter for brewing, and using Beer Smith to scale a 5 gallon recipe to 1.5-2 Liters for a starter.

So far I only brew 5 gallon extract kits, and haven't ventured out to PM or All Grain.

Here are my questions:

-If my extract kit comes with DME, can I use part of that DME to make my starter? (I figure doing this will effect my OG, but FG should be the same right?)

-Or is it best to get some DME from my LHBS to use specifically for starters only, without robbing from my actual extract kit?

-Do I add the scaled down amount of spices, ingredients, hops to my starter wort? Or should I just leave it plain, and will that effect final flavor at all?

-Will I need to do anything special with my yeast starter if I plan to use a stir plate? (I would think not, but I'm still a novice...I have the parts to make my stir plate, just have to put it all together.)

 

[BlackGoat]

I would have a dedicated bag of DME specifically for making starters. One reason is that - at least for me, I don't use a stirplate and I just shake the hell out of my starters as often as possible to introduce dissolved oxygen and to keep the yeast in suspension as much as I can. So, after a day or two, what I essentially have is a small batch of oxidized beer. I'm not real crazy about adding that to my beer, so I will cold crash the starter for a bit,then decant off the beer leaving only the yeast, which is what I pitch. Making a small version of what you are going to brew, including all the ingredients just sounds like an unnecessary hassle, and you may run into the oxidation issues. What do you plan to make your starter in? Most people use an erlenmeyer flask for their starters, which is placed on the stir plate. You will also need a stir bar.

 

[241]

I make starters every time I brew (or at least hydrate for things like nottingham). I have a stir plate and don't ever experience stuck fermentations or higher than desired final gravity. Stirstarter.com is a good place to get a cheap, well built stir plate. If you don't want to buy anything extra, just cover your flask with aluminum foil and shake it every time you walk by for 30 seconds or so. Make sure you get a big enough flask - I love my 2000 ml one.

As for your questions, BlackGoat is right. Keep a separate very light DME stash for starters. You can decant if you want, I don't as there are yeast in suspension and I'll take every last cell I can. Keep it at room temp. Try to get the temp of the starter wort the same temperature as your large batch when you pitch it. You can shock the yeast if there is too much of a variance - think jumping into a swimming pool in the morning.

No need to hop or spice the starter. Light DME is pretty tasteless, which is what you want your starter to be, and against the rest of your beer you won't even notice the taste (again why I don't decant personally).

This is all my opinion and what I do, you'll find a way that works for you.

 

[jwetzler]

So, after a day or two, what I essentially have is a small batch of oxidized beer. I'm not real crazy about adding that to my beer, so I will cold crash the starter for a bit,then decant off the beer leaving only the yeast, which is what I pitch. Making a small version of what you are going to brew, including all the ingredients just sounds like an unnecessary hassle, and you may run into the oxidation issues. What do you plan to make your starter in? Most people use an erlenmeyer flask for their starters, which is placed on the stir plate. You will also need a stir bar.

You have a good point I didn't think about the starter wort/beer becoming oxidized. I'm guessing there would still be a decent amount of oxidization if you saran wrapped the top of the container and left a small hole for ventilation.

When you cold crash your starter and dump the beer, do you wait for the yeast to warm to room temperature and then spoon it into the wort?

As far as the container for the starter, I'll either look for a flask, or use an oversized mason jar. I guess if I found something large enough that I could put a lid on, I could also punch a hole in it for an airlock.

Luckily I work in IT, so I have lots of old CPU fans, magnets, etc. I did pick up a stir bar. Also have a rheostat, just need a hobby box of some sort.

 

[jwetzler]

I make starters every time I brew (or at least hydrate for things like nottingham). I have a stir plate and don't ever experience stuck fermentations or higher than desired final gravity. Stirstarter.com is a good place to get a cheap, well built stir plate. If you don't want to buy anything extra, just cover your flask with aluminum foil and shake it every time you walk by for 30 seconds or so. Make sure you get a big enough flask - I love my 2000 ml one.

As for your questions, BlackGoat is right. Keep a separate very light DME stash for starters. You can decant if you want, I don't as there are yeast in suspension and I'll take every last cell I can. Keep it at room temp. Try to get the temp of the starter wort the same temperature as your large batch when you pitch it. You can shock the yeast if there is too much of a variance - think jumping into a swimming pool in the morning.

No need to hop or spice the starter. Light DME is pretty tasteless, which is what you want your starter to be, and against the rest of your beer you won't even notice the taste (again why I don't decant personally).

This is all my opinion and what I do, you'll find a way that works for you.

You and BlackGoat nailed it, exactly the info I was looking for. Thanks!

 

[jwetzler]

Hey thought of another question, when I make my starter wort, how long do I boil it for? Certainly not 60 minutes for such a small batch?

 

[BlackGoat]

I wouldn't punch a hole in anything, just wrap the top in foil. Since I don't use a stir plate, I just use a 1 gallon apple juice jug, I've heard of people improvising with similar things with their stirplates in case you don't feel like spending the cash on a flask. The oxidation problem isn't really THAT big of an issue, as 241 pointed out, so don't go overboard with it. As for pitching, my procedure is to take the starter out of the fridge at the beginning of my brew session (usually I have it in there overnight, or for at least 8 hours or so), pour off most of the liquid then let it sit at room temperature during the brewing. By the time you pitch a couple hours later it should have warmed up enough to where it will match up with your wort. Once you are ready to pitch, I just swirl the yeast in the starter to get it re-suspended in what small amount of liquid that I left in there and dump it on into the wort. As for boiling the starter, I usually go with about 5-10 minutes. You really are just trying to kill bacteria, so just long enough to do that is enough.

 

[241]

You're really only boiling to sanitize the liquid and DME. I boil for 10-15 minutes.

This link will be helpful for you, specifically the area around the below quote including cooling: http://www.howtobrew.com/section1/chapter6-5.html

Boil a pint (1/2 quart) of water and stir in 1/2 cup of DME. This will produce a starter of about 1.040 OG. Boil this for 10 minutes, adding a little bit of hops if you want to. Put the lid on the pan for the last couple minutes, turn off the stove and let it sit while you prepare for the next step. Adding a quarter teaspoon of yeast nutrient (vitamins, biotin, and dead yeast cells) to the starter wort is always advisable to ensure good growth. It is available from your brewshop.

If you add yeast nutrient, do it during the boil.

 

[jwetzler]

So when using a stir bar, do I need to keep the flask/jar uncovered so that oxygen to it is available?

 

[BlackGoat]

Most people wrap the top tightly with a piece of sanitized aluminum foil. some people use those foam stoppers that are designed for this purpose.

 

[jwetzler]

Most people wrap the top tightly with a piece of sanitized aluminum foil. some people use those foam stoppers that are designed for this purpose.

so the yeast doesn't necessarily need to be exposed to a constant source of oxygen, it just needs something to stir up everything.

 

[Flykilbosa]

So when using a stir bar, do I need to keep the flask/jar uncovered so that oxygen to it is available?

I use a foam stopper...works great. I wouldn't leave it uncovered though.

 

[BlackGoat]

so the yeast doesn't necessarily need to be exposed to a constant source of oxygen, it just needs something to stir up everything.

I can't speak to the science behind this, suffice to say I've seen it debated on this forum whether the purpose of the stir plate is to introduce a constant source of oxygen through a vortex, or whether its to keep the yeast constantly in suspension instead of letting them settle to the bottom. I suspect the latter but maybe someone can weigh in.

 

[kaconga]

A stir plate helps distribute the nutrients more effectively while maintaining a gas transfer. CO2 out and O2 in. These are the primary reasons yeast counts can be significantly higher than just a simple starter or intermittent shaking. However any form of starter with liquid yeast will improve your beer. Dry yeast don't need a starter.

 

[wherestheyeast]

Came across this the other day & it's appropriate to this conversation.

http://braukaiser.com/blog/blog/2013/03/19/access-to-air-and-its-effect-on-yeast-growth-in-starters/

Short: more oxygen = more yeast.

 

[BlackGoat]

Came across this the other day

interesting article, good stuff!

 

[ACbrewer]

If you are making a starter, it is preferable to decant, but if you can't decant (ie let the yeast settle and poor off the top) you can pitch the whole starter if it is small enough. Like 1L on a 5 gallon batch. Yes the beer is 'oxidized' but 2 things, 1 it gets diluted and 2 oxidized beer is beer where the yeast has gotten more O2 and is able to use more of the wort for energy. This usage takes out of the beer chemicals that you want to taste, like alcohol, and other byproducts.

Yeast need O2 not just to create energy, but to build sterols which are used to make more yeast. So the point of a stir plate is to allow more O2 exposure from the air, and to force off the CO2 in the solution. There is some preasure and such discussions about getting things through the cell membrane, but I'll leave that out of this.

Anyhow, a small starter in th 1L range can be safely added with little negative effect. Reasons for doing so? Well the most likely is that you need to make a starter but don't have enough time to let it settle - most likely with a wheat yeast. When you decant, the liquid while not clear, should be fairly clear/transparent. In the case of wheat, it take a long time to floculate, and if you decant the lighter yeast, you will have dumped some of the yeast that are specific to the style. In general, if you can make the starter ahead of time, and decant, you should.