60 minute boil vs 90 minutes boil

[ghosthef]

A quick question regarding boil times...I wasn't getting the best efficiency so I increased my spare volume and the boil time to 90 minutes. My efficiency has increased but I wasn't sure what other factors I should be aware of hen it comes to the longer boil time?

Thanks for any insight.

 

[Geordan]

Short of some very minor (most negligible, in my experience) additional darkening of the wort, the effects are positive: you're giving another 30 minutes of boil time to drive off DMS. Since a huge majority of my beers are pils based, I don't remember the last time I did a 60m boil -- you won't see any negative impact lengthening your boil.
Note that I still do my hop additions at T-60m.

 

[progmac]

increasing the boil time is not going to increase your efficiency...once the mash is over, your efficiency is what it is

 

[ghosthef]

Don't you get more sugars from the grain by increasing your pre-boil volume and boiling it down more?

 

[TrustyOlJohnson]

The efficiency of your mash is what it is, in percent, as a result of the types of grain you use, how your grains are milled and mashing technique and equipment, etc. However, continuing to sparge and collect beyond your preboil target volume, will carry more sugar to your boil kettle and increase your volume while decreasing the OG of the preboil wort. Mash runnings generally should not be collected once OG drops below 1.008-1.010 to reduce an increase in tannins. Once you have collected all you want, begin boiling and boil to you preboil target volume, the add your first (typically T-60) hop additions and follow your recipe. Boiling more than 60 minutes will decrease DMS, at the risk of carmelizing the sugars and darkening the wort with slight changes in flavor. However, the best method, remains an efficient mash and collecting the correct amount of preboil volume for the recipe.

 

[funnycreature]

The efficiency of your mash is what it is, in percent, as a result of the types of grain you use, how your grains are milled and mashing technique and equipment, etc. However, continuing to sparge and collect beyond your preboil target volume, will carry more sugar to your boil kettle and increase your volume while decreasing the OG of the preboil wort. Mash runnings generally should not be collected once OG drops below 1.008-1.010 to reduce an increase in tannins. Once you have collected all you want, begin boiling and boil to you preboil target volume, the add your first (typically T-60) hop additions and follow your recipe. Boiling more than 60 minutes will decrease DMS, at the risk of carmelizing the sugars and darkening the wort with slight changes in flavor. However, the best method, remains an efficient mash and collecting the correct amount of preboil volume for the recipe.

Isn't the increase in pH more important than the SG of the wort? But I agree that that's the cut-off most go by.

 

[betarhoalphadelta]

Based on this, I've been doing 90 minute boils for all beers:

http://bavarianbrewerytech.com/news/boilhops.htm

Unfortunately, that was written in 1999, is a random web site, and I'm not sure if the advice is still current wisdom of the brewing community. Anyone have anything more recent / more authoritative?

 

[progmac]

Don't you get more sugars from the grain by increasing your pre-boil volume and boiling it down more?

no, you just get a more concentrated wort. but the way you ask your question has me concerned that you are boiling grain...

 

[ghosthef]

Not boiling grain. Mash for 60-90 minutes...batch sparge. Had been hitting a preboil volume of 6.5 gallon and boiling the wort for 60 minutes. How I'm getting 7.25 gallons and boiling for 90 minutes.

 

[billl]

There seems to be a bit of confusion here on "efficiency".

Mash efficiency is how much of the available sugar you convert in the mash tun. That isn't impacted by how much you sparge.

Brewhouse efficiency is how much of the available sugar you get into the fermenter. That most certainly is increased if you use more sparge water to rinse the sugars out of the grain.

Of course, if your efficiency for a 60 minute batch is quite low, you might look at what the underlying problems are rather than just upping the sparge water. I'd spend a few minutes troubleshooting efficiency issues before adding an extra 30 minutes to every brewday.

 

[ghosthef]

Thanks Billl. I think my issue was one if sparge technique as well as equipment set up. I'm in a process of constant troubleshooting these days!

 

[Cyclman]

Efficiency is the amount of sugar going from the mash tun into the fermenter, a 90 min. boil can "fix" gravity but is more for DMS burnoff and more importantly, greater hop utilization. They seem intertwined, but really, they are separate processes.

I like a 90 min. boil, hops are expensive, why not optimize the utilization?

 

[billl]

"I like a 90 min. boil, hops are expensive, why not optimize the utilization?"

A 90 minute boil is going to up your utilization by a couple percent. Extending the boil from 60 to 90 minutes increases your fuel costs 50%. It really isn't a money saving proposition.

And you are using one of the many possible definition of efficiency in brewing. You an measure you efficiency at any step in the process, not just the final one. That is why it is important to specify what efficiency you are talking about when trouble shooting.

 

[eric19312]

I do the same to improve efficiency with larger grain bills. I batch sparge. My "normal" bill would be 12 or so pounds to make 5.5 gallons 1.050 wort. For that I collect total of 7 gallons, boil down to 6 gallons, transfer 5.5 - 5.75 gal to fermenter.

For bigger beers bill may be in 16-17 pounds range to make a 1.075-1.080 wort. With the larger bill, there is more sugar left in the water that wets the grain, so if I merely increased water enough to run off the same 7 gal I would lose efficiency. For these beers I will collect at least 7.5 gal and sometimes 8 in order to get closer to efficiency I get with smaller grain bills.

As for the economics, I am sure adding 30 min to my boil has a pretty modest impact on propane use...no way is it a 50% increase. I tend to burn pretty fast heating mash and sparge water, and bringing wort to a boil. Once a boil is reached I can turn my burner way down and maintain a vigorous boil. I run through about $4-5 per batch of propane. Guess dif between 60 and 90 min boil is probably $1. Am sure I make that back with improved efficiency given my grain costs. While grain is a savings i doubt if I save more than a quarter ounce of bittering hops with the higher utilization for the longer boil.

Finally I've only entered a couple competitions so far but my one award winner was from a beer that got a 150 min boil...adding to my favorable impression of longer boils.

 

[machfive55]

As someone mentioned, efficiency is what it is. You can drive off water by boiling more but your efficiency doesn't change. It will only change by perception because as you drive off water your gravity increases, but the volume is less so you have to calculate efficiency based on the new volume. Remember, efficiency is basically the ratio of sugar extracted from the mash compared to a theoretical maximum. I don't know why homebrewers get so hung up on it.

That said there are good reasons to lengthen a boil. Driving off DMS in lighter beers is one of them.

 

[ghosthef]

Thanks for all the feedback everyone. I think I'm going to change my set up and go back to a 60 minute mash/60 minute boil. Ordered some new equipment and off to buy supplies for a fly sparge set-up.

 

[StMarcos]

As someone mentioned, efficiency is what it is. You can drive off water by boiling more but your efficiency doesn't change. It will only change by perception because as you drive off water your gravity increases, but the volume is less so you have to calculate efficiency based on the new volume. Remember, efficiency is basically the ratio of sugar extracted from the mash compared to a theoretical maximum. I don't know why homebrewers get so hung up on it.

That said there are good reasons to lengthen a boil. Driving off DMS in lighter beers is one of them.

Well it sort of does. If you've used more water and ended up with more preboil volume, you've left less sugar in the grainbed and this corresponds to a higher extraction efficiency. What is true is that your efficiency of extraction is fixed once you've finished sparging/lautering, no matter the amount you intend to boil off.