Mash Temperature Chart: What Temperature and How Long to Mash

The short answer: most beers mash at 148 to 158°F (64 to 70°C) for about 60 minutes. The lower end makes a drier, more fermentable wort and a crisper beer; the upper end leaves more body and sweetness. If you are unsure, 152°F (67°C) for 60 minutes suits most pale ales, IPAs and lagers.

Mash temperature chart

Mash temperature	What you get	Good for	Time
146–149°F (63–65°C)	Very fermentable wort; dry, light-bodied beer; slightly higher ABV from the same grain	Saison, Belgian tripel, pilsner, light lager, brut IPA	75–90 min
150–152°F (66–67°C)	Balanced; fairly dry with some body	Pale ale, IPA, most lagers, wheat beer	60 min
153–155°F (67–68°C)	Medium body, a little sweeter	Amber, brown ale, porter, ESB	60 min
156–158°F (69–70°C)	Full body, sweeter, less fermentable	Stouts, Scottish ales, low-alcohol beers that still need body	45–60 min
168–170°F (76–77°C)	Mash-out: stops the enzymes and thins the wort for lautering	Any beer, 10 minutes at the end	10 min

A few degrees matter. Mashing at 148°F instead of 156°F can move the final gravity of the same recipe by several points, which you taste as the difference between crisp and chewy.

Why temperature changes the beer: the enzymes

Malted barley contains the enzymes that turn its starch into sugar. Each one works best in its own temperature band, and all of them wear out faster the hotter the mash gets.

Enzyme	Best range	What it does
Beta-glucanase	95–113°F (35–45°C)	Breaks down gummy beta-glucans. Useful with a lot of oats, rye or unmalted wheat, which can make a mash stick.
Protease	113–131°F (45–55°C)	Breaks down proteins. Modern, well-modified malts rarely need this rest, and a long one can hurt head retention.
Beta-amylase	131–150°F (55–65°C)	Snips maltose off the ends of starch chains. Maltose is highly fermentable, so more beta-amylase activity means a drier beer. It breaks down quickly above about 150°F.
Alpha-amylase	154–162°F (68–72°C)	Cuts starch chains anywhere along their length. That leaves dextrins, which yeast cannot ferment and which give body, and creates more chain ends for beta-amylase to work on.

A single mash temperature is a balance between the two amylases. At 148°F, beta-amylase does most of the work and the wort is very fermentable. At 158°F, beta-amylase fades fast, alpha-amylase dominates, and more dextrins stay in the beer. Holding separate rests to favour each enzyme in turn is called step mashing; see step mashing explained.

How long to mash

• 60 minutes is the standard. With modern base malts, most conversion is done in 30 to 45 minutes at 150 to 154°F; the extra time is insurance.
• Mash longer when you mash low. At 146 to 149°F the enzymes work more slowly, so give it 75 to 90 minutes for a dry beer.
• High mashes can be shorter. At 156 to 158°F, beta-amylase is mostly gone within 30 to 45 minutes, so extra time adds little.
• Check with iodine if you are unsure. Put a few drops of wort on a white plate and add a drop of iodine. If it turns black or purple, starch is still there; keep mashing. Throw the sample away rather than returning it to the mash.

Hitting your mash temperature

Strike water temperature

Grain at room temperature pulls the water down when you mix them, so heat your strike water above the target. The standard formula, in US units:

Strike temperature = (0.2 ÷ R) × (target − grain temperature) + target

R is your water-to-grain ratio in quarts per pound. Example: 1.5 qt/lb, grain at 65°F, target 152°F gives (0.2 ÷ 1.5) × 87 + 152 = about 164°F. In a thicker mash (1.25 qt/lb) you need about 166°F; in a thinner one (2 qt/lb) about 161°F. Pre-heat a cooler mash tun, or you will land a few degrees low.

Mash thickness

Traditional cooler mashes run 1.25 to 2 quarts of water per pound of grain (2.6 to 4.2 L/kg). Single-vessel and full-volume mashes run thinner, often 2.5 to 3.5 qt/lb, and that works well: a thinner mash is slightly more fermentable and holds its temperature evenly. Just keep the temperature and pH on target.

Mash pH

Enzymes also care about pH. Aim for 5.2 to 5.6, measured on a sample cooled to room temperature. See our mash pH guide and water chemistry guide.

Holding the temperature

Hitting your number at dough-in is half the job. A cooler mash tun loses a degree or two over an hour, and the grain bed is rarely the same temperature top to bottom. Stir well after dough-in and check in two or three places.

Recirculating electric systems solve both problems: a pump moves wort through the grain bed while a controller holds the setpoint, so the whole mash stays within about a degree. The Unibräu does this in a single vessel, and the BräuPro and HERMS system do it with a separate mash tun. A controller also makes step mashes and mash-outs a matter of changing the setpoint.

Common mash temperature mistakes

Problem	Likely cause	Fix
Beer finished sweet and heavy	Mash ran hot, often above 158°F	Calibrate your thermometer; mash lower next time
Beer is thin and watery	Mash too low for the style, or a very long low mash	Mash 3 to 5°F higher, or add a little crystal or Carapils
Low efficiency, starchy haze	Mash above about 165°F, which kills the enzymes before conversion	Let strike water cool before dough-in; iodine-test before lautering
Temperature all over the place	Poor mixing, cold spots, no recirculation	Stir thoroughly, pre-heat the tun, recirculate
Stuck or slow lauter	Lots of oats, rye or wheat; mash too cool at the end	Add rice hulls; do a mash-out at 168°F

Frequently asked questions

What temperature should I mash at?

Between 148 and 158°F (64 to 70°C). Use 148 to 150°F for dry, crisp beers, about 152°F for most ales and lagers, and 154 to 158°F for fuller-bodied beers.

Is 152°F a good mash temperature?

Yes. It is the most common single-infusion temperature because it balances fermentability and body, and suits most pale ales, IPAs and lagers.

How long should I mash?

About 60 minutes. Mash 75 to 90 minutes if you mash below 150°F for a very dry beer.

What happens if my mash is too hot?

Between about 158 and 165°F you get a less fermentable, sweeter wort and a beer that finishes high. Much above 165°F the enzymes die before converting all the starch, which lowers efficiency and can leave a starch haze.

What happens if my mash is too cold?

Below about 145°F conversion is slow. Give it longer and check with iodine, or raise the temperature. The beer will be dry and light-bodied.

What is the optimum temperature for beta-amylase?

About 140 to 149°F (60 to 65°C). It works across 131 to 150°F but breaks down quickly above that.

Does mash temperature affect ABV?

Yes. A lower mash makes more fermentable sugar, so the same wort ferments further and finishes with slightly more alcohol. A higher mash leaves more unfermentable dextrins.