“Sparge” water temp

[BrannDon]

Relatively new to BIAB and have a water temp question. Once my bag is hanging and draining post mash, I want to run some fresh hot water through the grains rather than just add water to hit my pre boil volume. Assuming that most enzymatic activity is complete after the mash, what would be he side effect/harm in rinsing with near boiling water straight out of my electric tea kettle? Some tannin extraction I suppose would be the obvious guess. Anyone have experience with this that can tell me more or less whether this will have an impact on my final product and whether I should just take the time hit and use proper temp water?

 

[doug293cz]

Boiling water is only a problem if the pH is 6 or above. Most tap water is above 6 pH, so it comes down to how much alkalinity is in the water, and is it enough to raise the pH within the grain mass to above 6. The easiest way to avoid this is to add a little lactic or phosphoric acid to the water to bring the pH down to about 5.6. Most water calculators should be able to tell you how much to add for your water (assuming you know the alkalinity of your water.)

Of course you don't even have to heat your sparge water to get an effective sparge. But you will have to spend a little more time heating to boil if you sparge with cool/cold water.

Brew on

 

[BrannDon]

Boiling water is only a problem if the pH is 6 or above. Most tap water is above 6 pH, so it comes down to how much alkalinity is in the water, and is it enough to raise the pH within the grain mass to above 6. The easiest way to avoid this is to add a little lactic or phosphoric acid to the water to bring the pH down to about 5.6. Most water calculators should be able to tell you how much to add for your water (assuming you know the alkalinity of your water.)

Of course you don't even have to heat your sparge water to get an effective sparge. But you will have to spend a little more time heating to boil if you sparge with cool/cold water.

Brew on

Interesting. Hadn’t even considered a cold sparge. I use hose water and my hose is sitting right next to the kettle... hmmm

I thought that water pH has the biggest effect on the mash. What would be the effect of the high alkalinity at this stage?

 

[doug293cz]

Interesting. Hadn’t even considered a cold sparge. I use hose water and my hose is sitting right next to the kettle... hmmm

I thought that water pH has the biggest effect on the mash. What would be the effect of the high alkalinity at this stage?

Water pH is pretty much irrelevant, it's the pH of the mash that matters. The enzymes work best with pH from about 5.2 - 5.7, and high pH (6 or above) can lead to tannin and silicate extraction. Most tap water (at least from municipal systems) has a pH around 8, but can have alkalinity from around 20 to over 100. It takes very little acid to lower the pH of low alkalinity water, but much more acid to lower high alkalinity water to the same pH, which is why the original pH of the water is much less important than the alkalinity. In the mash, the grain supplies some of the acid required to get the proper pH, but depending on the alkalinity of the water, and the type of malt, more acid may be needed to get to the proper pH range for the mash.

High alkalinity sparge water can raise the pH of the mash, and if pH goes above 6 and temps are above about 170°, then tannin extraction can get excessive. Keep the pH of the mash less than 5.8, and you don't have to worry about high temps.

Brew on

 

[Saunassa]

If I were to use hot water versus boiling water would I have to be as concerned with alkalinity and tannin extraction?

 

[kevin58]

Sparges are typically done at 168°. With BIAB just get yourself some heat resistant barbecue gloves and squeeze the bag. You'll be amazed at how much liquid is left in there.

 

[mongoose33]

If I were to use hot water versus boiling water would I have to be as concerned with alkalinity and tannin extraction?

The extraction of tannins happens when two things occur: high alkalinity and temps over 170. So if you sparge with hot water that's under 170, you will be fine.

When I was batch sparging (not BIAB but analogous), I always heated my sparge water while mashing. Why? It just shortened the time to bring the wort to a boil. Cold water would have sparged as well. Some people think that you need hot sparge water to "dissolve" the sugars remaining in your spent grain, but they're already dissolved. All you're doing is rinsing that sugar off and between the grain particles. It's already dissolved.

 

[mabrungard]

I keep telling brewers that its less about pH and temperature and more about the gravity of the final runnings. Its low gravity wort that increases the possibility of tannin extraction. Don't oversparge.

 

[LittleRiver]

... squeeze the bag. You'll be amazed at how much liquid is left in there.

That is certainly true if you squeeze the bag soon after you hoist it.

What I do is hoist the bag, fire the burner, and let gravity drain the bag into the kettle. It will drip for half an hour or more.

By that time there's not much liquid left in the grains. Not enough to make squeezing worth the effort.

 

[homebrewer_99]

I Batch Sparge with 200F water which raises my mash to about 164F when stirred in. No tannins.

 

[cloudybrewer]

That is certainly true if you squeeze the bag soon after you hoist it.

What I do is hoist the bag, fire the burner, and let gravity drain the bag into the kettle. It will drip for half an hour or more.

By that time there's not much liquid left in the grains. Not enough to make squeezing worth the effort.

Same here. I let it hang above the pot for most of the boil without ever squeezing. Sometimes i'll get bored and lift one side of the bag to roll the grain inside. When I dump the grain into a bucket during cleanup it appears mostly dry.

Although I have wondered, has all the water drained out of the grain carrying the dissolved sugars into the pot, or has the rising heat from the burner below the pot evaporated the water out of the bag leaving some sugars behind?

 

[RM-MN]

Same here. I let it hang above the pot for most of the boil without ever squeezing. Sometimes i'll get bored and lift one side of the bag to roll the grain inside. When I dump the grain into a bucket during cleanup it appears mostly dry.

Although I have wondered, has all the water drained out of the grain carrying the dissolved sugars into the pot, or has the rising heat from the burner below the pot evaporated the water out of the bag leaving some sugars behind?

The simple answer is no. The more complicated answer is that unless you add water (sparge) there will be sugars left behind no matter how long you let the bag hang. That then leads to another question, is there enough sugar left in that bag of grain to be worth a sparge step. I seem to gain 5 to 10% higher OG by sparging. YMMV

 

[LittleRiver]

... is there enough sugar left in that bag of grain to be worth a sparge step. I seem to gain 5 to 10% higher OG by sparging. YMMV

I'm getting ~83% efficiency with no squeeze and no sparge, and the ABV of my beers is where I want them to be. I'm enjoying the elegant simplicity of that.

Should I feel a need to make bigger beers then I always have the option of doing a sparge.

 

[brewbama]

I recommend mashing in a separate vessel (MLT) using the bag and grain bed as a filter and recirculate to get crystal clear sweet wort into the BK. This eliminates all the unwanted ‘stuff’ produced in the mash. If you mash in the same kettle and simply lift the bag you could get all that in the BK.

 

[doug293cz]

I recommend mashing in a separate vessel (MLT) using the bag and grain bed as a filter and recirculate to get crystal clear sweet wort into the BK. This eliminates all the unwanted ‘stuff’ produced in the mash. If you mash in the same kettle and simply lift the bag you could get all that in the BK.

And just what harm does that "stuff" cause to the taste and quality of the finished beer? References to authoritative sources preferred rather than anecdotes.

Brew on

 

[brewbama]

And just what harm does that "stuff" cause to the taste and quality of the finished beer? References to authoritative sources preferred rather than anecdotes.

Brew on

I simply made a recommendation. It’s certainly the brewer’s choice to brew how they see fit.

On the other hand, if references are required, and anecdotal comments are unwelcome on HBT, that tid bit should probably be posted in the ‘rules’. However, it would eliminate a large majority of all comments on this site.

But if you’re interested:

Fix in “Principals of Brewing Science (2nd Edition)”:

“The group of interest here is the long-chain, unsaturated fatty acids that are derived from malt. They are typically found in wort trub (i.e., particles suspended in the wort), which can consist of as much as 50% lipids (Meilgaard, 1977). Cloudy wort can contain anywhere from 5 to 40 times the unsaturated fatty-acid content of clear wort, an important fact because unsaturated fatty acids can have a significant negative effect even at low concentrations. On the positive side, fatty acids contribute to yeast viability via a number of mechanisms (see chapter 3), and they also inhibit the formation of some less pleasant acetate esters during fermentation (see chapter 3). On the negative side, they work against beer foam stability, as any fatty material does. Even more significantly, they play an important role in beer staling (see chapter 4). Thus, some investigations have reported that wort clarity (via trub removal) is essential (Zangrando, 1979), whereas other investigators have found some carryover of unsaturated fatty acids in the trub to be beneficial (Hough et al., 1981). In spite of these advantages, brewers still prefer clarified worts with minimum trub carryover, if for no other reason than the negative role wort-derived fatty acids play in beer staling. Another class of beer-staling constituents consists of fatty acids. In beer, fatty acids come from two sources, namely, unsaturated fatty acids from wort trub and saturated ones from yeast metabolism. As discussed in chapter 3, the saturated fatty acids can react with alcohols to form esters. The unsaturated fatty acids, on the other hand, are major players in beer staling. They tend to be fairly resistant to oxidation and spill over into the finished beer where they tend to produce “fatty or goaty notes.””

Kunze in “Technology of Brewing and Malting (5th Edition)”:

During malting the lipids are partly broken down and this breakdown is continued during mashing. This breakdown will later be of great interest to us. A large part of the lipids is later precipitated with the trub. Cloudy lautering and poor trub excretion lead to large amounts of free fatty acids in the wort, which the yeast cells require to produce new cell substances, but which can also contribute to a reduction in flavour stability.


I’ll leave to you to choose to use or not use the information as you see fit.

 

[doug293cz]

I simply made a recommendation. It’s certainly the brewer’s choice to brew how they see fit.

On the other hand, if references are required, and anecdotal comments are unwelcome on HBT, that tid bit should probably be posted in the ‘rules’. However, it would eliminate a large majority of all comments on this site.

But if you’re interested:

Fix in “Principals of Brewing Science (2nd Edition)”:

“The group of interest here is the long-chain, unsaturated fatty acids that are derived from malt. They are typically found in wort trub (i.e., particles suspended in the wort), which can consist of as much as 50% lipids (Meilgaard, 1977). Cloudy wort can contain anywhere from 5 to 40 times the unsaturated fatty-acid content of clear wort, an important fact because unsaturated fatty acids can have a significant negative effect even at low concentrations. On the positive side, fatty acids contribute to yeast viability via a number of mechanisms (see chapter 3), and they also inhibit the formation of some less pleasant acetate esters during fermentation (see chapter 3). On the negative side, they work against beer foam stability, as any fatty material does. Even more significantly, they play an important role in beer staling (see chapter 4). Thus, some investigations have reported that wort clarity (via trub removal) is essential (Zangrando, 1979), whereas other investigators have found some carryover of unsaturated fatty acids in the trub to be beneficial (Hough et al., 1981). In spite of these advantages, brewers still prefer clarified worts with minimum trub carryover, if for no other reason than the negative role wort-derived fatty acids play in beer staling. Another class of beer-staling constituents consists of fatty acids. In beer, fatty acids come from two sources, namely, unsaturated fatty acids from wort trub and saturated ones from yeast metabolism. As discussed in chapter 3, the saturated fatty acids can react with alcohols to form esters. The unsaturated fatty acids, on the other hand, are major players in beer staling. They tend to be fairly resistant to oxidation and spill over into the finished beer where they tend to produce “fatty or goaty notes.””

Kunze in “Technology of Brewing and Malting (5th Edition)”:

During malting the lipids are partly broken down and this breakdown is continued during mashing. This breakdown will later be of great interest to us. A large part of the lipids is later precipitated with the trub. Cloudy lautering and poor trub excretion lead to large amounts of free fatty acids in the wort, which the yeast cells require to produce new cell substances, but which can also contribute to a reduction in flavour stability.


I’ll leave to you to choose to use or not use the information as you see fit.

Thanks for the references. By anecdote I mean statements like: "I only send crystal clear beer to my BK and I make great beer." This is no more helpful than someone saying "I get very cloudy wort from my mash, but my beers are great." Both statements could be true, and that would imply that there are more important factors to making great beer than just the clarity of the wort going into the BK. But there is no actionable information in either statement without a lot more backup.

It's unclear to me if Fix is talking about wort into the BK or wort into the fermenter. He also says unsaturated fatty acids are bad, but they are also good. And then doesn't provide anything quantitative about how much FA is needed to achieve the benefits, or what the too much FA threshold is.

Kunze is definitely talking about wort into the fermenter. He also appears to say that a sufficient cold crash will precipitate out enough of the suspended material that the remainder is not an issue.

There seem to be three big concerns with the suspended material:

1. Amount of trub loss. This is mostly about whether the trub losses are accounted for in the bottom of the BK or the bottom of the fermenter. For some brewing setups it may make some difference in the overall system performance, but this has to be determined on a case by case basis.
2. Flavor stability. Fatty acids in the finished beer can degrade over time to create off flavors. This is often more important to commercial brewers, since they cannot guarantee cold storage throughout a beer's journey from brewery to customer. Homebrewers can more easily assure that they keep their beer cool/cold, which is very effective at slowing down staling reactions.
3. Foam stability. If this is important to you, then efforts to minimize FA's in the finished beer make sense.

For me, I don't see any reason yet to fret about clarity of the wort into the BK. YMMV.

Brew on

 

[brewbama]

Edited: I had counter points written but deleted them. “... this has to be determined on a case by case basis.” We agree. In my case, I recommend crystal clear sweet wort into the BK.

Cheers!

 

[dmtaylor]

I almost always use near-boiling water 190-200 F. No complaints of tannin extraction. Go for it.

 

[nh_homebrew]

Didn’t want to make a separate thread for this. My hot water is 110 Fahrenheit. Would this be sufficient for sparging?

 

[doug293cz]

Didn’t want to make a separate thread for this. My hot water is 110 Fahrenheit. Would this be sufficient for sparging?

Yes, but you may need to acidify it if it has significant alkalinity.

Brew on