Half size batch questions

[snipper_cr]

So I have a few beers under my belt. My big "hold up" between brews (I avoid saying problem) is that 5 gallons is a LOT of beer to drink, even with help. I would like to make smaller batches to give me more chance to experiment and try new batches. Plus given my current residence, smaller is better, especially when it comes to boiling water!

So I have quite a few questions on half size brewing. As far as ingredients, I understand that you halve all the ingredients EXCEPT yeast. What about hops? I hear that hops depend on the gravity. Since both the ingredients and water have been halved, the gravities SHOULD be the same right?

As far as yeast, to them its almost as if I've doubled the amount of yeast cells. So for instance, if a 5 gallon recipe called for 60billion cells, I should be fine with a 30 billion cell vile of liquid yeast?

I would assume boil times do NOT chance, still 60 minutes with normal hop additions. With boiling, evaporation would be a bigger problem I bet since loosing 1/4quart of water to evaporation is far more significant with 2.5 gallons versus 5 gallons.

How about gravity readings? They should be the same right? For instance if I have a recipe that calls for a SG of 1.050 and final of 1.015, I should expect those with a half gallon recipe?

If I use specialty grains, I would use half the amount? What about a partial mash? Half water and grain bill? All-grain; half water and grain bill? I have not done any all grain yet but I figured I'd ask now in case I do half size all grain further down the road.

Finally, would I use half the priming sugar when bottling?

Thanks!

 

[cyberbackpacker]

I highly recommend investing in some brewing software. If you are on a PC Beersmith cannot be beat; honestly for as much money we spend on brewing $20 for the software is a sound investment. Additionally they offer a free trial to test it out: BeerSmith Brewing Software, Recipes, Blog, Wiki and Discussion Forum

That being said, Beersmith has a "scale" feature that will take any recipe and it automatically scales it up or down as you need it. It gives you the proper amount of hops, water, grains, extract, etc. to make the recipe exactly as the original, just for a different final volume. So if you have a recipe for a 5 gallon batch, you just select the "scale" button, type in 2.5 if you want a true "half-batch", click enter, and your recipe is now exactly scaled for 2.5 for everything needed to brew.

Additionally though, your boiling times always remain constant.

 

[McGarnigle]

I don't see why people say not to halve the yeast. Granted yeast amounts do not have to be as precise as grains or hops, but there is a potential downside to over-pitching. This may mean not having to do a starter, or perhaps throwing out half of a dry yeast packet.

 

[ifishsum]

For that matter, you could probably do all-grain half batches with the same equipment you'd use to do a partial mash full batch. My little 2 gallon round cooler will do 5 lbs of grain comfortably, enough for a 2 gallon batch in the Mr. Beer keg.

 

[cyberbackpacker]

I don't see why people say not to halve the yeast. Granted yeast amounts do not have to be as precise as grains or hops, but there is a potential downside to over-pitching. This may mean not having to do a starter, or perhaps throwing out half of a dry yeast packet.

You are quite correct... however liquid yeast vials or smack packs are actually at perfect levels for 2.5 gallon batches, and to be at ideal pitching conditions for 5 gallon batches, a starter needs to be utilized. So in this instance, the idea of not halving the yeast could do with this.

As far as dry yeast... the cell count is appropriate for 5gallon batches in a dry yeast pack, but I have utilized full packets on countless 2.5g batches without any perceptible drawbacks (and these beers have been bjcp reviewed).

I believe that the threshold for negative side-effects of overpitching are much higher than what a dry yeast pack gives you. However underpitching side-effects are seen/occur much easier in my experience.

 

[murphyslaw]

So it wouldn't matter if you're ale pail is half air?

 

[cyberbackpacker]

During primary fermentation enough co2 is produced to provide a nice blanket over the wort that the extra headspace is not an issue.

Additionally, I rarely use an airlock, and I do not use a secondary, and as a rule primary for 6 weeks on all but very few batches.

I have never had oxidation issues (and have had bjcp review on my beers). With so much head space I do not see a need for an airlock; I just use a lid on top of the pail without a grommet hole. It is not an "airtight" seal so the co2 is able to displace o2 through this opening.

This is just the way I do my 2.5-3g batches.

 

[aidanpryde18]

If you want to do Secondary of a 2.5 to 3 gallon batch, buy a 3 gallon better bottle. These things are wonderful.

I also have to second the recommendation of brewing software, the scale function and boil-off automation are invaluable sources for brewing.

I went to 3 gallon batches so that I could do all-grain on a stovetop full boil. I will never look back. It makes about 24 Grolsch bottles, which is perfect for my drinking habits.

I have a couple of extract five gallon batches if someone wants me to make beer for a party, but other than that, all I do is 3 gallons.

Good luck.

 

[cyberbackpacker]

You can also use carlo rossi wine jugs for fermenters... I use three for a 2.5 gallon batch. They hold over 1 gallon each, and I can get as many as I want for free.

 

[jennieD]

This thread has great info, I'm a noob and also have the need to brew in smaller batches.

You can also use carlo rossi wine jugs for fermenters... I use three for a 2.5 gallon batch. They hold over 1 gallon each, and I can get as many as I want for free.

This is a great idea...do you fit the jugs with some kind of airlock?

 

[cyberbackpacker]

Yes, I use a drilled rubber stopper (I cannot remember the size right now) with an airlock.

 

[Indy418]

+1 On BeerSmith. Plug in the recipe or your own for a 5 gal. batch then convert to three to 2.5 gal. It's what I do and have had no problems.

And it lets me do all grain without having a turkey fryer or jet engine to boil my wort.

 

[secinarot]

I do small batches (3 gal) for beer styles that I know my BMC loving friends and family will not like. Beersmith or other software is invaluable when formulating recipes, and well worth the investment.

 

[Bob]

Other folks have answered many of these questions, but I figured I'd add my tuppence.

So I have a few beers under my belt. My big "hold up" between brews (I avoid saying problem) is that 5 gallons is a LOT of beer to drink, even with help. I would like to make smaller batches to give me more chance to experiment and try new batches. Plus given my current residence, smaller is better, especially when it comes to boiling water!

You and me both. I prefer 3-gallon batches.

So I have quite a few questions on half size brewing. As far as ingredients, I understand that you halve all the ingredients EXCEPT yeast. What about hops? I hear that hops depend on the gravity.

Yes and no. While the grist can be scaled linearly, the hops cannot. Has to do with different boil dynamics, surface-to-volume ratios and the like. It'll take some time and empirical evidence to give you an idea of how to scale hops additions.

As for yeast, the pitching rate - 0.75 to 1 million active cells per milliliter of wort per degree Plato - doesn't change dependent on the volume. If you're pitching a wort of 12P (1.048), you still need to pitch approximately 12 million cells per milliliter. Refer to the Mr Malty page for further information.

Since both the ingredients and water have been halved, the gravities SHOULD be the same right?

Yes.

I would assume boil times do NOT chance, still 60 minutes with normal hop additions. With boiling, evaporation would be a bigger problem I bet since loosing 1/4quart of water to evaporation is far more significant with 2.5 gallons versus 5 gallons.

Also correct. Exact numbers need to be established through empirical observation - you'll need to measure your pre-boil and post-boil volumes to determine exactly what percentage of loss you experience.

How about gravity readings? They should be the same right? For instance if I have a recipe that calls for a SG of 1.050 and final of 1.015, I should expect those with a half gallon recipe?

Because the grist can be linearly reduced, the OG should remain the same.

As for FG, the best advice I can give you is to stop relying on the paper. Yeast can't read. The FG is never dependent on recipe, but on the individual ferment. Different yeasts will perform differently given the exact same fermentation parameters, and a single yeast will perform differently if the fermentation parameters change. A piece of paper can't know your particular fermentation parameters, so there's no way you should look on the recipe's FG number as some Grail. You dig?

Finally, would I use half the priming sugar when bottling?

You're best off consulting a carbonation calculator for that. Most brewing software will contain a calculator.

You've gotten recommendations on software, which I will now cloud. I prefer ProMash, mainly because I've been using it for the best part of a decade. Opinions differ. Play with as many different software suites as you can before making a decision.

Bob

 

[snipper_cr]

Been messing around in Beer Smith with scaling recipes. It scaled down my hops to half... that is correct? I thought I read somewhere that when scaling recipes to NOT scale hops down cause its not the amount but gravity that matters. Truth to this?

+1 for Beer Smith. Just downloaded and will be buying later on when I get to my wallet and a secure computer. Great program!

Happy friday! It's 5 Oclock somewhere!

 

[Bob]

Been messing around in Beer Smith with scaling recipes. It scaled down my hops to half... that is correct? I thought I read somewhere that when scaling recipes to NOT scale hops down cause its not the amount but gravity that matters. Truth to this?

Again, yes and no. As I wrote above, hops do not scale linearly, but it's nothing to do with gravity in the kettle. Though kettle gravity does affect utilization (lower gravity = better utilization), the thing that affects hops in recipe scaling is boil dynamics.

BeerSmith is giving you a place to start, because there's no way - none - to predict how the scaling will affect utilization in your brewery. You have to start somewhere, though, before you can start brewing and assembling data empirically; scaling hops amounts by the same percentage as you're scaling your malt gives you as good a starting point as any.

You dig?

Bob

 

[snipper_cr]

NQ3X Thanks for the great replies. I typed my response to the previous post and then THOUGHT I clicked "submit reply" and walked away from my computer. Came back a bit later and saw I didnt so I clicked it again... AFTER your post. Sorry about that!

But great information there. Looks like I'll be doing some experimentation. For my first few batches, I'll scale my hops back linearly, at least according to Beer Smith. Worst that happens is I get a bit overly sweet beer but instead of 5 gallons of it, I only have 2.5 gallons of it... way more manageable!

Thanks again!

 

[Bob]

I find I get more bitterness when I scale linearly. Others report less-efficient extraction. All you can do is drink it!

I know, I know - the horror.

Bob