Tannin Detection

[Fletch78]

If I boiled too much residue from bad vorlaufing, or screwed up the sparge, and suspect tannin extraction, is it something you can detect in the post-boil hydro sample, by taste, or does the sugar mask it?

Thanks!

 

[Malticulous]

You can taste it, or more correctly feel it. Nothing covers it up. The best it could do is balance it.

Some brewers have questioned the need to vorlauf and have stopped doing it. It's not as important as has been thought.

 

[Fletch78]

Ok, good. I didn't taste any.

On vorlaufing, I vorlaufed for about an hour and it still wasn't running clear, and the mash was starting to gelatinize and stick, so I went ahead and just started collecting wort and batch sparging about a gallon at a time (limited space, couldn't add it all at once)

My 3rd AG batch. 1st Zap Pap method.

 

[Malticulous]

The not clear wort may even be good for fermentation. You may want to read page 76 in the pdf from the Weihenstephan.
http://mediatum.ub.tum.de/doc/619244/619244.pdf
They continually raked the mash as they took the first running. It ran off much faster that way.

If you got tannin extraction it was from the sparge. The poor vorlauf had nothing to do with it. And as long as you had good conversion you should not have any starch haze in the final beer.

 

[Fletch78]

So grain bits in the kettle, boiled, don't contribute to tannin extraction?

 

[Fletch78]

Wait a minute... I just watched some of the decoction mash sticky from Kaiser.. he's boiling grains. I have always been told that extracts tannins and makes the beer taste bad.

 

[Malticulous]

Tannins come from the husks. To extract them you need high temp and high pH. Because the pH goes down as you sparge over sparging can extract them.

 

[nebben]

I was initially confused too about the concept of a decoction mash. It seems contradictory to common advice to not get your mash above 168F or else tannin extraction can occur.

I believe I did do a sparge with too hot of water though a few batches ago. I even entered the beer into a homebrew competition- and got "astringent" on all three judges reports. My suspicion is that I either sparged too hot, had a bad crush, or a combination of the two.

 

[Revvy]

Boiling grains do not extract tannins (yes we boil when we decoct) squeezing the grain bag doesn't cause tannins (in BIAB squeezing the grain bag is recommended.) Despite all those things we've "heard" the only thing that cause tannins to be produced is you PH AND high temps together.

From Aussie Homebrewer.com

Tannins And Astringency

If you are worried about squeezing your bag too much or crushing too fine, relax! Astringent beers do not come from finely crushed or squeezed husks but come rather from a combination of high temperatures and high pH. These conditions pull the polyhenols out of the husk. The higher your pH and the higher temperature you expose your grain to, the worse the problem becomes. Any brewer, traditional or BIAB, should never let these conditions arrive. If you do allow these conditions to arrive, then you will find yourself in exactly the same position as a traditional brewer. Many commercial breweries actually hammer mill their grain to powder for use in mash filter systems because they have control of their pH and temperatures. This control (and obviously expensive complex equipment) allows them non-astringent beers and “into kettle,” efficiencies of over 100%.

From BYO, MR Wizard;

The two most influential factors affecting the extraction of tannins from malt into wort are pH and temperature. All-grain brewers are very careful not to allow wort pH to reach more than about pH 6 during sparging because tannin extraction increases with pH. In all-grain brewing wort pH typically rises during the last stages of wort collection and is one of the factors letting the brewer know that wort collection should be stopped.....

Temperature also affects tannin extraction. This relationship is pretty simple. If you don’t want to run the risk of getting too much tannin in your wort, keep the temperature just below 170° F.

This is where the answer to your last question begins. You ask whether steeping and sparging released "unwanted tannins" in your beer. For starters, all beer contains tannins. Some tannins are implicated in haze and some lend astringent flavors to beer.

The type most homebrewers are concerned about are those affecting flavor. In any case, it is up to the brewer to decide if the level of tannins in their beer is too high. The (in)famous decoction mash is frequently recommended when a brewer is in search of more malt flavor. Decoction mashes boil malt and — among analytical brewers who are not afraid of rocking the boat with unpopular ideas — are known to increase the astringent character associated with tannins. In general I wouldn’t consider 170° F dangerously high with respect to tannin extraction. However, if you believe your beers may suffer because of too much astringency, consider adjusting your steep pH and lowering the temperature a few degrees.

 

[Malticulous]

The batch I had noticeable tannins in did not get over 168F. The pH was the problem and channeling may have been part of why. That helped push me to batch sparging.