Head Retention Experiment: No-Rinse vs Rinse

[yankinoz]

An experiment showed that one no-rinse sanitiser, one based on phosphoric acid + surfactant, reduces head retention; that is, rinsing improved retention.

In each of two trials, well-carbonated 60% wheat beer was poured from two bottles that had been filled in close succession from primary. To avoid cross-contamination the fermenter had been rinsed with boiled water before filling with wort.

Defender was used on all bottles before draining upside down for four minutes and filling. In each trial I rinsed one bottle twice with boiled water (“Rinse”) and left the other bottle unrinsed (“No Rinse”). Five weeks after bottling I poured each into a glass.

The results of each trial were nearly identical. Beer from the “Rinse” bottle about 40% of its head after three minutes. Beer from the “No Rinse” bottle lost almost all its head after only two minutes.

I took photos but could only attach one this post, because of site limits on file size. I can send a full set to interested parties as email attachments.

Here's the photo of the beer from the rinsed bottle three minutes after pouring

View attachment images2.pdf

In contrast the beer from the No-Rinse bottle retained a head only around the rim. It did have nice lacing.

Discussion:

Threads on no-rinse sanitisers and head retention have appeared on this and other brewing websites, but actual experiments are hard to find. One I did find is meant to test Star-San, but has little value because it really compares the head produced during filling, which is subject to variables that are hard to control.

Only further experiments can determine how applicable the results are to other no-rinse sanitisers. Unlike Defender, Iodophors do not contain surfactants. Star-San contains the same surfactant, dodecylbenzenesulfonic acid, that is reportedly used in Defender, but not necessarily in the same concentrations, and Star-San also contains a foaming agent that the manufacturer's website does not identify.

Because kegs have a smaller internal surface area than a collection of bottles holding the same volume of beer, remnant sanitiser should be less in kegged beer than in bottled beer, assuming equally good drainage. From my measurements of tall neck 500 ml bottles and online measurements of 5 gallon corny kegs, the internal surface area of (38) bottles would be about 2.8 as great as that of the corny keg.

Brewers who keg and/or use Iodophor or Star-San may wish to do a like trial. It's easy as experiments go.

 

[Parks]

While I haven't done the test on star san I've never had any head issues and use it very liberally.

--EDIT-- removed dumb comment

 

[verysupple]

Defender has a surfactant in it and you wonder why it harms head retention :blink:

While I haven't done the test on star san I've never had any head issues and use it very liberally.

Apparently Star San has the same surfactant. It seems you think the OP should expect a loss of head retention when not rinsing Defender, but you say you use Star San and don't have any problems. So which do you believe? The surfactant does or does not harm head retention?

Anyhoos, thanks to the OP for posting. It's always good when someone actually does an experiment.

And FWIW I use Defender (I think it's just called Phos-san now) and don't rinse it. My head retention seems fine. Who knows though, maybe it would be better if I rinsed.

 

[Parks]

Ah, well there you go.

I wonder if it could be the result of incorrect strength or if the Phos-san has different "inert ingredients" that affect it.

 

[Jack of all biers]

Yankinoz,

Thanks for posting your experiment results. It's not something I had considered (effects on head retention), but I religiously rinse with boiled water (twice) to flush out the visible foam (I use Star San) in a just in case fashion.

You may well have considered this variable and covered off on it, but your post doesn't allude to it. What about the glasses the beers were poured into? The glasses may have various residual amounts of dirt/grease/fat deposits or surfactants/detergent that will effect head retention.

I know you had the consistency of similar head retention with two lots of rinse and no-rinse bottles, but it maybe that you were unlucky in glass selection. I'm sure there will be other variables to consider in this type of experiment, but that is the one that springs to fore for me.

Edit - (after thought) Another variable maybe the amount of carbonation from one bottle to another, which may effect the time the head stays in a higher formation (you stated the no-rinse still had good lace remaining around the sides), so therefore equal carbonation in the individual bottles is also an important variable. From this I would also say that if there was a detrimental effect on the head retention, could it be possible that the residual sanitizer is effecting the amount of viable yeast (given the lower amounts at this stage of fermentation) to carbonate the bottles? Could this have a greater effect on head retention as opposed to the surfactants effecting it? Not sure, but another variable to take into consideration.

 

[wobbly]

Interesting topic.

At times I bottle fully carbonated beer from out of my Williamswarn (to tide me over between brews!!) that when consumed direct from the machine have appropriate head retention yet when consumed from the bottle within a short time after bottling (1 week?) the head retention is non existent. Yet some time later (2-3 weeks maybe longer?) the same beer pours with acceptable head retention. It's not the glasses as they receive the same washing regime for consumption of all my beer. My thoughts to date have been focusing on the bottle washing regime to make sure that there wasn't some detergent residue remaining in the bottles.

A web search (http://discussions.probrewer.com/archive/index.php/t-9942.html) has indicated that there is some discussion that the Dodecylbenzenesulfonic Acid (surfactant) contained in Star San (and similar sanitizers) which I have been using can impact on head retention. I haven't paid very careful attention to the concentration I mix to the point I have most likely erred on the high side by maybe as much as 50/75% (?) above the recommended rate of 1.5ml/Lt. Previously when I brewed in a traditional plastic fermenter and bottle carbonated etc I used an Idophor solution without issue and only changed to Star San about the same time as I started using the Williamswarn.

The above article also references the use of Hydrogen Peroxide (sodium per carbonate) as an alternative because it doesn't contain the surfactant. Interestingly Sodium Percarbonate is the sanitizer detailed in the Williamswarn manual so the next beer I bottle I will try using sodium per carbonate instead of the Star San and see what if any difference that will/does make (if any)

Wobbly

Edit:- Don't have the answers as to why the beer would would pour acceptably after a "few" weeks in the bottle. These are just observations not answers.

 

[Jack of all biers]

Interesting topic.

At times I bottle fully carbonated beer from out of my Williamswarn (to tide me over between brews!!) that when consumed direct from the machine have appropriate head retention yet when consumed from the bottle within a short time after bottling (1 week?) the head retention is non existent. Yet some time later (2-3 weeks maybe longer?) the same beer pours with acceptable head retention. It's not the glasses as they receive the same washing regime for consumption of all my beer. My thoughts to date have been focusing on the bottle washing regime to make sure that there wasn't some detergent residue remaining in the bottles.


Edit:- Don't have the answers as to why the beer would would pour acceptably after a "few" weeks in the bottle. These are just observations not answers.

Could the above suggest that the lack of carbonation is the greater factor in the lack of head retention more so than the surfactant effect? One would think that if the surfactant is the problem then it wouldn't improve after a few weeks? Maybe with Wobbly's experience above the beer fresh from his "Williamswarn" (sorry I'm not familiar) holds its head as it is fully carbonated (correct me if this is not the case with the Williamswarn). So when it is then bottled, it naturally loses some of the carbonation due to the bottle head space and after one week isn't able to re-pressurise. After a few weeks with the yeast being able to fully carbonate, this may be the reason for the return of the head retention?

Wobbly will have to correct my assumptions as I am totally unfamiliar with his method or the "Williamswarn".

Or could it be possible that the surfactant breaks down into something else after a few weeks mixing with the brew? Anyone have any theories?

 

[Yob]

I haven't paid very careful attention to the concentration I mix to the point I have most likely erred on the high side by maybe as much as 50/75% (?) above the recommended rate of 1.5ml/Lt..

You do realise that starsan is not considered to be a no rinse solution used above its recommend ratios right?

Why would you not pay attention to this?

 

[manticle]

Could the above suggest that the lack of carbonation is the greater factor in the lack of head retention more so than the surfactant effect? Anyone have any theories?

A beer with the right proteins and dextrins can form and hold a head with very little carbonation.

 

[Matplat]

Really? To me it seems that the level of carbonation is directly linked to the amount of head?

 

[manticle]

Fizziness and/or an aggressive pour is one of the factors that will lead to bubbles gathering in the mouth of the glass. For that to form and remain as a proper head rather than short term froth relies on other factors. A low carbonated beer containing the right proteins, dextrins and hop oils will hold a nice, dense, tight head. A glass of fizzy coke or a straight kit and kilo will not.

I've mentioned before but I bookend my sacch rest with a short 55 rest and a slightly longer 72 rest. My carbonation errs on the low side (not quite cask ale but usually around 1.8 - 2). Fizzy beers does not directly correlate to good head formation and has little to do with retention.

 

[manticle]

Here's a rough breakdown:
http://brewwiki.com/index.php/Head_Retention

My experience bears this out.