Does pH matter for BIAB?

My question is more on timing. I've read and experienced that with BIAB, conversion happens very quickly. By the time i get my corrected mash pH readings conversion has pretty much finished. I can hit my 5.2 by making the correct additions, but is it already too late?

Does pH still matter as it steeps after conversion?

Should i be more "predictive" with my pH and prep my water based on my ingredients? I use Beersmith and it can predict my pH based on the recipe. But i hesitate to add acids based on that without an accurate reading first.

thanks for your help

Short answer:. Yes. Water chemistry plays an important part in the mash, and also influences the taste of the final product (some of the only brulosophy experiments to find a statistical difference were the water chem ones)

Long answer: if it ain't broke, don't fix it. Perhaps your water combined with the recipes you like to make always seen to find a nice pH without additional help. If your water is mild on all the major minerals, and you aren't doing recipes that usually require major adjustment (huge dark beers or low alcohol pale beers) then you may never want to mess with it. I have ****ty water, so I buy RO for $0.30 a gallon. Adjustments are required for many beers with that or I get like 55-60% efficiency.

pH is probably more important with BIAB then with the traditional method because using the traditional method, you can adjust your mash pH by adjusting your mash thickness, atleast to a certain degree. With the BIAB full volume method, you have to adjust your water to hit the right pH range when the grain is added.

This is exactly what I'm trying to understand.

Biscuits said:

pH is probably more important with BIAB then with the traditional method because using the traditional method, you can adjust your mash pH by adjusting your mash thickness, atleast to a certain degree. With the BIAB full volume method, you have to adjust your water to hit the right pH range when the grain is added.

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hoey222 said:

My question is more on timing. I've read and experienced that with BIAB, conversion happens very quickly. By the time i get my corrected mash pH readings conversion has pretty much finished. I can hit my 5.2 by making the correct additions, but is it already too late?

Does pH still matter as it steeps after conversion?

Should i be more "predictive" with my pH and prep my water based on my ingredients? I use Beersmith and it can predict my pH based on the recipe. But i hesitate to add acids based on that without an accurate reading first.

thanks for your help

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As @Biscuits and @ZebulonBrewer stated, pH in BIAB is important. In answer to your second question regarding predictiveness, I say yes. While no software is 100% accurate, they can be used with great success. Beersmith is good, but I prefer Bru'n Water (BW). I've found that once I got my existing water chemistry numbers from Ward, the pH results from BW were almost always within +/- 0.1 of what I checked using a meter. Hope that helps. Ed


ETA: BTW, I normally shoot for a pH of 5.4 (a little lower for light lagers, a little higher for dark/black beers.) That way +/- 0.1 still puts me in the "sweet spot."

Conversion happens quicker with BIAB - Why?

shetc said:

Conversion happens quicker with BIAB - Why?

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Well, it's not because it's in a bag but a benefit of what the process allows. You can crush the grains to flour and still not have a stuck sparge.

There is definitely benefit in controlling pH with BIAB;

- I'm not convinced conversion occurs that quickly. Even so, you will leave it for an extended period and a high pH will extract tannins

- Controlling mash pH ensures correct pH downstream

I've brewed BIAB both controlling the pH and not and noticed great differences, definitely worth fiddling with!

hoey222 said:

This is exactly what I'm trying to understand.

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* Forenote: When I say 'BIAB' I am referring to those that do full volume mash. As some, including myself, do a version of BIAB that is really the same as a traditional 3 vessel method of mash and sparge where the bag is essentially a false bottom and makes cleanup a bit easier.


Simply put (because I am not smart enough to understand the complicated way) BIAB has a much thinner mash (water>grain) which means the natural buffering ability of the grain is not enough to effect the entire volume of water. If you play around in Bru'n Water and change the mash volume value, you can clearly see that as you make the mash thicker, the pH will drop closer to the desired pH range -to an extent.

Typically, water you buy or from your tap is somewhere in the 7.0-8.0 pH range which is considered neutral, but the desired mash pH (room temp) is somewhere between 5.2-5.6 (acidic). If you were to perform a thick mash, more than likely the grain would naturally get you close and if not a small amount of acidulated malt or an acid of some type (i prefer acid malt but sometimes use lactic acid) will get your pH where you want it. With a thin BIAB mash, the grain cannot reduce the pH enough on it's own so you will have to make adjustments before doughing in so that after the grain is in the liquor your pH is in range and the appropriate enzymes and other science'y stuff can happen and no tannins or other off-flavor producing reactions occur.

Hope this helps.

I challenge the assertion that conversion happens faster in BIAB. Can you support this claim with quantifiable data?

Mash pH is important regardless of what type of all-Grain process is used. The challenge with BIAB is that the mash is much thinner, meaning there is less grain per gallon to pull the pH down into the correct range.

It is probably fair to say that "Conversion" does not take any longer with BIAB than it does with any other method. Saying this requires you to assume that the speed of conversion dependent only on available starches and enzymes. If a BIAB and other type of mash could be done to release starches and enzymes at the same speed, then you should expect conversion (the actual time it takes for enzymes to convert starches) to be the same.

What is faster with BIAB (and no, this has not been measured, though some have done conversion tests) is that by grinding the grain finer, the kernel is broken up into smaller chunks. This increases the surface area of the kernel which is in contact with the wort. This makes it easier for the starches to disolve into the wort. This makes the starches available for conversion by the enzymes faster.

So while conversion may technically be as fast under both conditions, a mash with a more finely crushed grist should be able to allow for faster extraction of starches which should allow for conversion to complete faster as all starches become available before they would be available with a more coarse grist.

All that being said, I definitely agree that pre-adjusting your brewing liquor before starting the mash based upon predictions from Bru'n Water (or some other tool) is key to producing the best beers unless you are blessed with perfect water which the majority of us will not be.

Is it typical to finely grind the grain for BIAB? I was going to just have it crushed as usual.

Many people get increased efficiency with a finer or double grind.

Javaslinger said:

Is it typical to finely grind the grain for BIAB? I was going to just have it crushed as usual.

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I've either forgotten to double-grind my grain or just didn't bother, and I miss my OG by 10 points every time. Since I've started double-grinding every time, I hit my numbers every time, with 80% efficiency.