Full or partial boil? Hops in too long?

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

pms67

Senior Member
Supporting Member
Joined
Feb 6, 2014
Messages
3,310
Reaction score
1,441
Location
Bannockburn
Kill two birds with one stone here and ask both on the same thread.
What do you guys find is the main difference between a full volume boil and a partial boil then topping up the concentrated wort? I only boil what can fit into my Burco then top up the rest when I’m transferring to my no chill cube.
Also, how can you leave hops in the FV for too long and get “grassy” flavours but everyone is now chucking them into the corny kegs for weeks on end and it’s deemed fine?

cheers
 
I always do a partial boil of 6L and then top up to 19 or 20L in the FV. I am an extract brewer as I have neither the time, equipment or space for AG. I think the main differences are to do with the hops. I have read many recipes that state a full boil is necessary in order to achieve the correct bitterness. Another problem that I have noticed is with recipes that use a lot of oats. I have a recipe for Mikkeller's Breakfast Beer Geek stout that is only for AG and it states that because of the amount of oats involved, it would be extremely difficult to replicate the recipe using extract.

As far as the grassy flavour thing goes, I have heard numerous theories. But I have recipes that say to dry hop for 2 weeks. I made an IIPA recently and dry hopped for 9 days. No grassy flavours that I could pick out. Someone on here suggested it might be something you can get from UK hops but not so much with US hops. I just try and stick to the recipes as best I can and things usually turn out fine. Can't say I have ever made a grassy flavoured beer and I dry hop a lot of my brews.
 
I am now a partial mash brewer. My recipes are all based on 1kg pale malt plus other grains and 1.5kg DME, with a majority of the DME going into the FV without being part of the boil. The final volume in the FV is governed by the recipe but is usually 19-21 litres. The boil is done in an 11 litre stockpot and wort volume is about 9 litres. I have had to scale down down full volume recipes and have found it can be a bit of art in getting the hop bitterness and flavour right for different recipes, although with experience I am now beginning to get to where I want to be. However I cannot really say how my method of working compares with a full volume boil recipe.
Never dry hopped for more than 7 days and never picked up 'grassy' flavours.
 
It depends on how much you top up. My cooker-top pot gives me about 10 litres of wort by the time it's boiled for an hour or so, and my FVs are 12 litres so I boil all the grain and hops for 12 litres and then "liquor back" (as James Morton would have it) to 12 litres with low-mineral, mineral water. If I've missed the Target OG, I might top up to less than 12 litres. If you use the Brewers' Friend hop IBU- Bitterness calculator you can work out how much more hops to put in. The stronger the wort, the less alpha acid is isomerised so you need more hops for the same IBUs. personally I don't bother, but if I was doubling the amount of liquid in the top up, then I would.

I don't believe leaving hops in a keg for weeks on end is a good idea, Some are grassier than others- Cascade, for example, is awful. I always dry hop in the secondary FV, using a hop sock, and for no more than three days. Just about all the flavour is extracted at then end of the second day in any case.

On one occasion, I made a mild and on another a session bitter by making 10 litres and topping up to 20. In each case I pitched the yeast into the 10 litres and diluted the brew the following morning so I could have time to boil the water and let it cool. In both cases, and with different yeasts the fermentation stunk to high heaven and the off-flavour was still detectable in the beer when it was conditioned. i can only assume that diluting the beer, once it has strarted fermenting, stresses the yeast.
 
IMG_20200107_180418_burst_02.jpg
I do partial boils most of the time: hoppy beers.
I use 1/4-1/2 of the extract in 2 quarts of water and boil 15 minutes with hops. I then mix in the remaining extract and add 6 quarts of ice cold water and pitch the yeast.
I'm quite satisfied with how it turns out.
 
I make 19-20L batches.

I mash with with 15L, so not quite full volume. I sparge with an additional 5L boiling water.

After moisture retained by grains and lost in boil, I tend to get about 17L at the end of the brew. I add a large 2L ice chunk after the immersion coil for cooling extra fast and topping up the quantity.

d1Pqerr.jpg
 
Kill two birds with one stone here and ask both on the same thread.
What do you guys find is the main difference between a full volume boil and a partial boil then topping up the concentrated wort? I only boil what can fit into my Burco then top up the rest when I’m transferring to my no chill cube.
Also, how can you leave hops in the FV for too long and get “grassy” flavours but everyone is now chucking them into the corny kegs for weeks on end and it’s deemed fine?

cheers

Your choice is limited as you haven't the room in your boiler, but as long as your top up water has been sterilised and treated, (presuming you adjust your water) it is fine. As for the dry hops, I don't go over the 7 day mark, 4 days is really all you need to extract the oils (which won't be much) and you can reuse the dry hops in another brew.
 
Why is it called dry hopping when they get soaked?

Shouldn't it be called cold hopping?
 
Your choice is limited as you haven't the room in your boiler, but as long as your top up water has been sterilised and treated, (presuming you adjust your water) it is fine. As for the dry hops, I don't go over the 7 day mark, 4 days is really all you need to extract the oils (which won't be much) and you can reuse the dry hops in another brew.
I’ve never heard of anyone using the hops twice but everyday is a school day!
Another quick question, I have made a pale ale and there isn’t enough bitterness, is there anything that can be done now? Also the hops you use for a dry hop, has the bitterness been extracted from them or just flavour/aroma?
 
I make 19-20L batches.

I mash with with 15L, so not quite full volume. I sparge with an additional 5L boiling water.

After moisture retained by grains and lost in boil, I tend to get about 17L at the end of the brew. I add a large 2L ice chunk after the immersion coil for cooling extra fast and topping up the quantity.

d1Pqerr.jpg
FWIW, I stopped sparging my steeping grains a while ago and it has had no noticeable difference. It is just another corner you can cut without repercussions.
 
I’ve never heard of anyone using the hops twice but everyday is a school day!
Another quick question, I have made a pale ale and there isn’t enough bitterness, is there anything that can be done now? Also the hops you use for a dry hop, has the bitterness been extracted from them or just flavour/aroma?

The hops are processed the same, whether used for boiling to add bitterness or for dry hopping to add aroma.

I've got to say though, the idea dry hopping only adds aroma is a myth, it adds plenty of flavour too, just more floral than when boiled. Try a bottle of BrewDog Dead Pony, nearly all the hop flavours are from dry hopping.

https://brewdogrecipes.com/recipes/dead-pony-club

People sometimes choose hop varieties specifically for dry hopping, usually ones that have low alpha acid levels, but there is no rule.

You could try getting a bottle of hop aroma oil. Get an idea of what it does by adding some to a can of commercial lager. You add it to the finished beer or to the keg while it is conditioning.

https://www.themaltmiller.co.uk/ingredients/?category=hop-aroma-oil
 
Last edited:
Your choice is limited as you haven't the room in your boiler, but as long as your top up water has been sterilised and treated, (presuming you adjust your water) it is fine. As for the dry hops, I don't go over the 7 day mark, 4 days is really all you need to extract the oils (which won't be much) and you can reuse the dry hops in another brew.
I have never seen anyone reusing hops
 
I’ve never heard of anyone using the hops twice but everyday is a school day!
Another quick question, I have made a pale ale and there isn’t enough bitterness, is there anything that can be done now? Also the hops you use for a dry hop, has the bitterness been extracted from them or just flavour/aroma?
You can still add isomerised hop extract after fermentation has finished to increase the bitterness.

I have never seen anyone reusing hops
Cold water/wort can extract very little bitterness from the dry hopping, making it possible to use the hops post dry hopping in another beer.
Have a read of Dry Hopping Oregon State University a thesis by Peter Wolfe.
 
Back
Top