Diluting partial boils with Wort/Apple Juice?

[vast_reaction]

Hi there. I think this question belongs in this category, if not I'll be happy to re-post it where it needs to be.

I live in an apartment, and do stove-top brewing. I have a 5-gallon brewpot, and I tend to boil about 4 gallons, which leaves me with a 3.5 gallons of wort that I need to top up to 5 before pitching. When I made a wheat beer, I used a gallon of apple juice, which had a SG of 1.042. I didn't even realize this was helping me to maintain efficiency at the time.

My question is, should I keep doing this? The resulting beer didn't really have an apple flavor from just 1 gallon, and it added some alcohol content. Are there downsides to topping up to the 5 gallon mark with, say... a 1.050 wort? I want to brew a stout in the 1.070 range, but it will be hard since I have to do partial boils. Anything that anyone can add on this would help! Thanks a million.

-Matt

 

[WrongCoastBrewery]

I have the same problem with doing partial boils all the time. My stove only can boil about 3-4 gallons without it taking an eternity to boil. Someone suggested to me to make a heatstick to help to do full boils. I have yet to do this but once my current project (keezer) is up, I will be moving onto the heatstick.

This is the link to making a heatstick:

http://www.cedarcreeknetworks.com/heatstick.htm

 

[MetallHed]

Make a concentrated wort from the partial boil and dilute with spring water to bring it down to the style/target OG.

This is common for pretty much every kit I've ever seen sold online for extract and partial mash brews.

Changing the volume of the boil will change the IBU, color, and gravity of the final beer.

If you are making your own recipes and you don't already have a beer program, get one. You can then adjust the amount of water used to determine the final outcome of your beer.

 

[frazier]

Is there a downside to using AJ? Not if you want what it provides! Check out Brandon O’s Graff recipe for an example. But if it’s beer you want, the AJ will add a flavor that may or may not go with the recipe.

I wouldn’t think of it as “increasing your efficiency.” More like, adding simple sugars, since it doesn’t change the amount of maltose you get from the grains. Where I come from, AJ has an SG of 1.050 – 1.052. So one gallon in a 5 gal batch will raise the OG by ten points (.010).

It sounds like you’re brewing with extract, doing partial boils. If you have enough extract in the recipe to reach your target gravity, it doesn’t matter (with regard to gravity) if you add it all at the start and do a concentrated boil, or add some (or most) of the extract toward the end of the boil. When you top off to 5 gallons with water at the end, you automatically reach the target OG. The AJ would put you over the top (by 10 points). If you want the boost, and the apple flavor, fine. Otherwise, just increase the amount of extract, which will give you more beer in your beer.

 

[Justibone]

Also, if using apple juice, ensure that it doesn't contain preservatives (other than ascorbate, *not* sorbate).

EDIT: to be clear --
sorbate - BAD (in fermenting beer)
ascorbate - GOOD (yeast like citric acid)

 

[vast_reaction]

If you have enough extract in the recipe to reach your target gravity, it doesn’t matter (with regard to gravity) if you add it all at the start and do a concentrated boil, or add some (or most) of the extract toward the end of the boil. When you top off to 5 gallons with water at the end, you automatically reach the target OG.

This is where I'm slightly confused. I use Beersmith to generate my recipes. I made a recipe for a stout with an OG of 1.064, but my Boil Volume is only 4 gallons. I lost .5 gallon due to evaporation last time, so I plan to end up with 3.5 gallons of wort. Using Beersmith's dilution tool, it shows that adding 1.5 gallons of water will make the gravity 1.045.

Making a stout with an OG of 1.091 will drop it to 1.064. Is that the way to do it with a partial boil? Make a super concentrated wort and dilute it? Sorry for my long-windedness.

 

[ReverseApacheMaster]

Making a stout with an OG of 1.091 will drop it to 1.064. Is that the way to do it with a partial boil? Make a super concentrated wort and dilute it? Sorry for my long-windedness.

Yes.

If you top off a partial mash with apple juice you do risk some apple flavor but probably more likely you're going to get the dryness associated with cider because apple juice is completely fermentable.

If you top off with either apple juice or wort you are going to reduce your IBUs. That's why you need to concentrate both sugar and hops in the partial boil so it will dilute down to the correct OG and IBUs.

 

[robbyg]

If you're using Beersmith to design your recipes, you're probably trying too hard on this one. When you're building your recipe, just uncheck the box that says "Set Boil Volume Based on Equipment" and manually enter your boil volume (4 gallons in this case). Beersmith already calculates for evaporation, and will assume you're topping off your batch with water to make up for the lost volume.

Therefore, your OG estimate would be based on a 4 gallon boil, with evaporation, and then topping off to reach your final batch size.

 

[vast_reaction]

Holy crap, you're right. I already uncheck that box, I have my Boil details set to my equipment, etc. However, why doesn't the estimated OG change when I change the boil volume? Just for kicks, I changed to boil volume to 2 gallons, assuming a .25 gallon loss from boiling. That would mean adding 3.25 gallons of water... but the estimated OG didn't change at all. That seems impossible. Thanks for the help though.

 

[frazier]

Holy crap, you're right. I already uncheck that box, I have my Boil details set to my equipment, etc. However, why doesn't the estimated OG change when I change the boil volume? Just for kicks, I changed to boil volume to 2 gallons, assuming a .25 gallon loss from boiling. That would mean adding 3.25 gallons of water... but the estimated OG didn't change at all. That seems impossible. Thanks for the help though.

The OG depends on two things, and two things only: The amount of sugars going in, and the final volume. That's all.

 

[Tombstone0]

However, why doesn't the estimated OG change when I change the boil volume?

Because your OG is based on the volume in your fermenter and the amount of fermentables. For a 5 gallon recipe the volume in the fermenter will be 5 gallons and the fermentables will be whatever the recipe called for. The boil volume doesn't effect either so it doesn't matter when you're calculating the OG.

 

[vast_reaction]

Wow. That was pretty concise, lol. Thank you all for the information, I think I've got it clear in my head now. If it tastes good, I think I win. High five.