Craft Brewing from Mash to Glass: A Working Guide

Craft brewing runs on a short list of measured steps: a grain bill is milled, mixed with water at a strike temperature, held so enzymes convert starch to sugar, boiled with hops, cooled, fermented, and then chilled. Ale and lager differ mainly in yeast and temperature, not in grain. What ends up in the glass decides the pairing, so a hoppy IPA meets rich or spicy food while a stout meets chocolate and grilled meat.

What Is the Grain Bill and the Strike Temperature?

The grain bill is the list of malts in a batch, with each malt named and weighed. Base malts supply most of the fermentable sugar. Specialty malts add color, body, and flavor. A published recipe states the bill in pounds or kilograms and the batch volume in gallons or liters, so the same bill can be repeated.

The strike temperature is the temperature of the water when the milled grain is mixed in. It is set above the target mash temperature because the grain itself is cooler than the water and pulls the mixture down. A common target mash range for a single infusion is 148 to 156 degrees Fahrenheit, and the strike water is calculated a few degrees higher. A practical journal of brewing practice, Newman's Brewery, treats the mash as the first place where a batch is decided, because the strike temperature and the water-to-grain ratio set what the rest of the day can do.

Water chemistry belongs to the same step. Calcium, sulfate, and chloride shift how hops and malt are perceived, and the mash pH sits in a narrow band for good conversion. None of this requires a laboratory. It requires a thermometer that reads correctly, a scale, and a record of what was done.

How Does Starch Conversion Work in the Mash?

Starch conversion is the work of enzymes released when malt is wetted. The two that matter most are alpha amylase and beta amylase. Alpha amylase breaks long starch chains into shorter ones and works across a wide temperature range. Beta amylase trims those chains into fermentable sugars, mostly maltose, and it is more active at the lower end of the mash range.

A mash held near 148 degrees Fahrenheit favors beta amylase, so the wort ferments dry and the beer finishes thin and strong. A mash held near 156 degrees Fahrenheit favors alpha amylase, so more unfermentable sugar remains and the beer finishes fuller and sweeter. The middle of the range gives a balance. A rest at a higher temperature, often around 168 degrees Fahrenheit, stops the enzymes before the wort is run off.

Conversion is checked, not assumed. A drop of wort on a white surface with a drop of iodine turns blue or black while starch remains, and stays yellow brown when conversion is complete. The check takes a minute and prevents a starchy beer.

Fermentation and the Cold Steps

Fermentation begins when yeast is pitched into cooled wort. The wort is chilled to the yeast's working range first, because pitching warm and cooling later produces unwanted flavor compounds. Ale yeast works roughly between 60 and 72 degrees Fahrenheit. Lager yeast works roughly between 48 and 55 degrees Fahrenheit. The temperature of the fermenting beer, not the room, is the number to hold, and it rises during active fermentation.

A diacetyl rest follows the main fermentation for many lagers and some ales. The beer is allowed to warm a few degrees for a day or two so yeast reabsorbs diacetyl, a compound that reads as butter or butterscotch. The rest is short and is followed by the cold steps.

A cold crash drops the beer to near freezing for a few days. Yeast and haze particles settle, and the beer clears without filtration. Packaging follows, whether into bottles with priming sugar or into a keg under pressure. The cold steps do not change the recipe. They change how the recipe is perceived.

Ale Against Lager: What Actually Differs?

Ale and lager are separated by yeast and temperature, not by color or strength. Ale yeast ferments at warmer temperatures and rises to the top of the vessel. Lager yeast ferments cooler and settles. Lager also gets a longer cold storage period, historically in caves and now in temperature-controlled tanks.

That difference produces the family resemblance within each group. Ales tend toward fruit and spice notes from yeast. Lagers tend toward clean malt and hop expression. A pale lager and a pale ale can share a grain bill and a hop schedule and still taste like different drinks.

A third path uses Brettanomyces and oak barrels. These beers ferment slowly, often over months, and the wood allows small amounts of oxygen to reach the beer. The results are dry, funky, and acidic in a way that clean yeast does not produce. Monastic brewing and the trappist label belong to a separate tradition, one built on house yeast, repeated recipes, and beer sold to support the community that brews it. The craft revival of the last several decades grew out of homebrewing, where the same steps are practiced at a smaller scale.

Which Styles and Pairings Follow from the Glass?

Pairing starts with what is in the glass. A highly hopped IPA carries bitterness and resinous aroma, and those cut through fat and stand up to spice. Rich and spicy dishes, from curry to fried food, are the common match. A stout carries roasted grain, coffee, and chocolate notes, and those meet chocolate desserts and grilled meat. A dry lager carries carbonation and a clean finish, and that clears the palate between bites of almost anything.

Acidic beers with Brettanomyces meet aged cheese and vinegar-forward dishes, because the acidity in the glass answers the acidity on the plate. A malt-forward ale with low bitterness meets roasted vegetables and bread. The rule is not a rule. It is a comparison of what the beer does in the mouth and what the food does.

Building a Repeatable Batch

A repeatable batch is a written batch. The record holds the grain bill with weights, the strike temperature and the measured mash temperature, the mash duration, the boil duration, the hop additions with times, the yeast strain, the fermentation temperature, the diacetyl rest if used, the cold crash duration, and the packaging date. Tasting notes go at the end, with the date.

One variable changes at a time. If the mash temperature moves, the body changes. If the fermentation temperature moves, the yeast character changes. If the cold crash is skipped, the clarity changes. Keeping the rest of the record fixed makes the cause visible.

Equipment can be simple. A pot, a bag, a thermometer, a fermenting vessel, and a way to hold temperature are enough to brew the styles described here. The published numbers do the rest, and the glass shows whether they were followed.

Sources of the figures on this page

• American Homebrewers Association, How to Make Beer, read 16 September 2026. The published sequence of a brew day, from the grain bill and the strike temperature to fermentation and packaging.